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COPYRIGHT DEPOSIT, 



The Technical Control 
of Dairy Products 



THE 

TECHNICAL CONTROL 
0/ DAIRY PRODUCTS 

A Treatise on the Testing, 

Analyzing, Standardizing and the Manufacture 

of Dairy Products 



By 

Timothy Mojonnier, M. S. 

President Mojonnier Brothers Company 

Milk Engineer 
Consulting Chemist for Dairy Industries 

and 

Hugh Charles Troy, B.S.A. 

Professor of Dairying, in charge of 

Testing in the Department of Dairy Industry 

Cornell University, Ithaca, New York 

Consulting Chemist for 

New York State Department of Farms and Markets 

Formerly State Chemist, New York 



FIRST EDITION 



Published by 

MOJONNIER BROS. CO. 

Milk Engineers 

CHICAGO, ILLINOIS 

1922 






Copyright, 19^2, by Mojonnier Bros. Co. 

Copyright, 1922, in Great Britain and other countries. 

All rights reserved. 



FRED KLEIN CO, 
PRINTERS 
CHICAGO 



OCT 10 '2? 

IC1A686421 



To all who are interested in the 

progress of the dairy industry, in 

its varied branches, this book is 

dedicated. 



Preface 



IN THE compilation of this book, the authors have endeavored 
to systematize and present a large amount of original in- 
formation and data, in such a way as to make it of the greatest 
value to teachers, students, plant operators, chemists and dairy 
control agencies. Some of the material has already appeared in 
addresses, and technical papers, but the larger part has not hereto- 
fore appeared in print. The diagrams and standardizing tables 
shown in Chapters X to XIV inclusive, have been developed in 
connection with and used for some time, with Mojonnier stand- 
ardizing equipment, and in instruction work. They are incorporated 
in this book with the hope that a larger number may profit by 
their proven merit and utility. Drawings and tables largely based 
upon original data are used frequently to make more clear the 
operation and application of several new methods and appliances 
for testing and controlling dairy products. The numerous graphs 
shown have been drawn from tabulated results of carefully planned 
and executed experiments, some of which have covered a period 
of several years. 

It is realized that there are many milk plant practices upon 
which opinions differ, but the aim in this book is to present facts 
and methods that have proven in actual practice to possess the 
greatest merit. Constructive criticisms or suggestions that readers 
may be prompted to make will be greatly appreciated. 

Acknowledgment of other sources of information as far as 
])ossible is made in the text. Special credit is due to Mr. J. A. Cross 
for conspicuous services as mentioned in several places in the text ; 
to Mr. W. O. Frohring for valuable suggestions in connection with 
Chapter XVI, as well as for arranging for the loan of numerous 
valuable graphs and photomicrographs from the Telling-Belle- 
Vernon Co. ; to Mr. O. W. Mojonnier for valuable suggestions in 
connection with Chapter XIX ; to Mr. Roscoe Moon for help and 
co-operation in the preparation of illustrations and in proof reading; 



X PRKI'ACE 

to the Fred Klein Co., Chicago, 111., for excellent co-operation in 
all matters pertaining to the printing of the book, and to Mr. H. J. 
lyiedel for careful aid in many ways. Credit is further due to 
Mv. J. J. Mojonnier. Miss Lucy Klein, Mr. E. C. Jensen, Mr. Len 
Fortney, Mr. H. O. Buhrman, and others connected with Mojonnier 
Bros. Co. Acknowledgment is also made of courtesies extended 
by Mr. Mark Shanks of the Standard Ice Cream Co., Chicago, and 
Mr. Mark Goodman, of the Goodman- American Ice Cream Co., 
Chicago. Till' Authors. 



Contents 



CHAPTER I 1-9 

The Dairy Plant Laboratory: Location; Floor; Ventilation; Temperature; 
Tables and desks; Hood; Sinks; The microscope; Steam and electricity; 
Lighting; Apparatus; General plans for dairy laboratories. 

CHAPTER II 10-33 

The Constituents of Milk: General statements; The physical properties 
of milk; The composition of milk; Variations in content of fat and solids not 
fat; Distribution of constituents; Gases; Water; Total solids; Solids not fat; 
Milk fat; Casein; ililk sugar, solubility, crystalline condition, uses; Albumin; 
Mineral constituents; Lecithin; Vitamines; Citric Acid. 

CHAPTER III 34-61 

History and Principles of Fat and Total Solids Tests: Various fat tests; 
The Mojonnier milk tester; Reagents used in the Mojonnier Milk Fat test, 
their functions; Results of comparative fat tests by Mojonnier and other 
methods; Proofs of accuracy of fat tests by Mojonnier method; Total solids 
and moisture tests; ^lojonnier total solids and moisture tests. 

CHAPTER IV 63-69 

Assembling the Mojonnier Milk Tester: Its different parts, their uses. 

CHAPTER V 70-79 

Preliminary Instructions for Operating the Mojonnier Milk Tester: Care 
to give the tester; Care and use of the balance; Influence of temperature 
upon results obtained in weighing; Care to give power unit, water circulating 
imit, vaciuim ovens, cooling ovens; Turning on the current; Heating, weigh- 
ing and cleaning fat and solids dishes. 

[xil 



xii Contents 

CHAPTER VI 80-92 

Sampling Dairy Products: Sampling milk ami cream; Composite sam- 
ples, preservatives, care, preparation and testing; Sampling whole milk for 
making evai)orated and sweetened condensed milk; Sampling skim-milk, 
evaporated milk, sweetened condensed milk, ice cream mix, ice cream, butter, 
buttermilk, cheese, whey, powdered milk products, malted milk, milk chocolate, 
cocoa. 

CHAPTER VII 93-119 

Directions for Making Fat Tests, Using the Mojonnier Milk Tester: 
Weighing the samples; Adding the reagents; ^Jixing milk and reagents; 
Pouring of!" the ether solution; Evaporating the ether solution; Weighing 
the fat dish; Recording results and calculating percentages; Running blanks 
upon reagents; Testing for fat, milk, skim-milk, whey, buttermilk, evapor- 
ated milk, condensed buttermilk, sweetened condensed milk, ice cream, cream, 
malted milk, chocolate, cocoa, butter, skim-milk powder; Order of operations 
in testing evaporated milk for fat and total solids with the ilojonnier tester; 
Precautions; Causes for high tests; Causes for low tests. 

CHAPTER VIII 120-129 

Directions for Making Total Solids Tests, Using the Mojonnier Milk Tester: 
Outline of method; Weigliing samples for fat and solids tests; Treatment 
given dishes during the evaporation of moisture; Cooling and weighing the 
solids dishes; Calculating percentage of solids; Testing for total solids, whole 
milk, skim-milk, whey, buttermilk, evaporated milk, unsweetened and sweet- 
ened condensed milk, condensed buttermilk, ice cream mix, cream, malted milk, 
milk chocolate, cocoa, clieese, butter, skim-milk powder, whole milk powder, 
buttermilk powder; Causes of too high solids tests; Causes of too low solids 
tests. 

CHAPTER IX 130-141 

General Information on Standardizing Dairy Products: Standardization 
defined; Steps involved; Obtaining samples and weights; Methods to use in 
testing and calculating results; Order of operations; Principles of calculations 
involved. 

CHAPTER X 142-161 

Calculations for Standardizing Whole Milk and Cream: Standardizing 
for fat; The use of various products; Standardizing for both fat and solids; 
Problems met in standardizing milk and cream; Problems worked out in 
detail. 



Contents xm 

CHAPTER XI 163-319 

Standardizing Evaporated Milk: Successive steps in standardizing before 
condensing; Constants for evaporated milk; Order of operations in standardiz- 
ing; Recording standardizing data; Obtaining weight of the finislied batch; 
Calculating the point at which to strike the batch; Relation between tempera- 
ture and specific gravity; Relation between specific gravity and composition; 
Calculation of Baume reading at any desired condensation; How to strike the 
pan batch; Holding tanks; Standardizing tables; Key to standardizing formu- 
las; Problems in standardizing evaporated milk both before and after con- 
densing and methods for solving them. 

CHAPTER XII 220-371 

Standardizing Sweetened Condensed Milk: Successive steps; Methods of 
sampling; Testing; Order of operations; Recording data and obtaining 
weights; Striking the batch; Relation between specific gravity and composi- 
tion; Improved method and equipment; The use of tables in shortening calcu- 
lations; Key to formulas; Problems in standardizing before condensing and 
methods for solving them; Tables for ascertaining sugar required. 

CHAPTER XIII 273-432 

The Composition and Standardization of Ice Cream Mixes: Suggested 
composition; Physical and chemical properties; Composition ratios; Nutritive 
ratios; Commercial factors as influenced by composition; Functions of the 
various constituents; Relation of gelatin to the incorporation of air; Sources 
of supply of ingredients ; Name and description of flavors, fruits and nuts used 
in ice cream and sherbet; Relation of composition to ice cream defects; Sandy 
ice cream, its cause and prevention, influence of sugar crystals, pasteurization, 
composition, overrun, solubility of milk sugar on sandiness; Influence of 
sugar and gelatin; Standardization, steps involved; Method of compounding, 
Order of operations; Kinds of problems encountered in standardizing; Key to 
factors in formulas; Problems in standardizing and methods for solving them; 
Use of unsweetened condensed skim-milk in ice cream mix; [Methods of calcu- 
lations for using sweetened condensed skim-milk; Tables for calculating the 
amount of sweetened condensed skim-milk and how to use them; Proofs of 
accuracy of tables; Compounding ice cream mixes of various tests from vari- 
ous products; Methods of calculations for deriving ingredient formulas; Ta- 
bles giving mixes of various compositions. 

CHAPTER XIV 433-442 

The Standardization of Miscellaneous Dairy Products: Unsweetened con- 
densed milk, milk powder, chocolate, cocoa and milk cliocolate. 



xiv CONTKNTS 

CHAPTER XV 443-475 

The Overrun in Ice Cream: General facts regarding overrun; Different 
pliases in freezing and liardening ice cream; Proper overrun; Composition; 
Aging; Acidity; Viscosity of the mix; Homogenizing and drawing the mix 
into the freezer; Type of freezer; Brine temperature; Control of freezing 
operation; Pvctaining the overrun; Relation of gelatin to overrun; The Mo- 
jonnier Ice Cream CHerrun Tester; Setting up and applying the Mojonnier 
Overrun Tester; Standardizing the overrun; Determining the overrun in ice 
eieanr containing crushed fruits. 

CHAPTER XVI 476-553 

Microscopical and Bacteriological Tests of Dairy Products with Directions 
for the Care and Use of Cultures: The microscope in the dairy industry; 
Microscopical examination of fat in dairy products; Bacteria in milk; Patho- 
genic bacteria in milk; Bacteria producing acid but no gas; Acid gas pro- 
ducers; Common types of fungi found in milk; Quantitative determinations 
of milk organisms; Collection of samples for bacteria counts; JNIicroscopic 
colony count; Standard methods of bacterial milk analysis; Microscopic count 
of bacteria (Breed method); Verification and researcli methods; Detection of 
specific pathogens in milk; Commercial applications of bacteria to dairy prod- 
ucts; Apparatus designed to propagate pure cultures; Description of the 
i\iojonnier Culture Controller and Sterilizer used with the ^Mojonnier Culture 
Controller; Propagation of cultures and summary of directions for operating 
the Mojonnier Culture Controller; The application of pure cultures in the 
manufacture of buttermilk; pot cheese, baker's cheese, cheddar cheese and 
butter. 

CHAPTER XVII 554-683 

Analysis and Miscellaneous Tests of Dairy Products: Specific gravity de- 
terminations; Lactometers; Formulas for calculating milk solids; Baume and 
Twaddell hydrometers; Calculating percentages of adulteration by skimming 
and watering; Determining viscosity; The Mojonnier-Doolittle viscosimeter 
and directions for operating it; Casein determination and tests; Nitrogen 
determination by Kjeldahl-Gunning method; Determining quality of casein; 
Determining percentages of albumin, milk sugar, sucrose, in dairy products; 
Qualitative tests for sucrose; Relative solubility of milk powders; Determin- 
ing lecithin and citric acid; Standard solutions; Acid tests; Alcohol test; 
Tests for preservatives, gelatin, added color; Butter analysis; Cheese analysis; 
Melting point of milk fat; Detecting foreign fats: Reichert-Meissl number; 
lodin number; Detecting giuns and thickeners; Analyzing salt; Analyzing 
vanilla extract, gelatin, gum arabic, gum tragacanth; Specific heat and freez- 
ing point of dairy products and their determination; Preparation of pure milk 
constituents; Hydrogen ion concentration and its electrolytic and colorimetric 
determination. 



CoNTKNTS XV 

CHAPTER XVllI 0S4-7 18 

The Purpose and Advantage of the Vacuum Pan in the Dairy Industry: 
Description of the vacuum pan; Tlie vacuum pump; Tlie steam piping; Eola- 
tion of condenser water required to water evaporated; Steam required to con- 
dense milk; Relation of gas, oil and coal to steam production; Calculating 
the water, steam and fuel required; Operating tlie vacuum pan; forewarming 
milk, starting and controlling the evaporation, striking and finishing tlie 
batch, superheating the batch; Precautions in pan operation, condition of 
heating surfaces, air leaks; Influence of bicarbonate of soda; Cleaning the 
pan; Entrainment losses; Sweetened condensed whole milk and skim-milk, 
forewarming, operating the pan, striking the batcli; Condensing other liquid 
dairy products. 

CHAPTER XIX 719-771 

Evaporated Milk: Its Sterilization and Physical and Chemical Control: 

Sterilizing; The ]Mojonnier Evaporated Milk Controller; Factors that influ- 
ence tlie coagulating point; Steam distribution in the sterilizer; Standardiza- 
tion of fat and total solids; Sodium bicarbonate solution and its use; Prepar- 
ing, sterilizing and cooling sample cans; Testing sample cans for viscosity 
and color; Adding sodium bicarbonate before sterilizing; Adjusting sterilizing 
records upon different sizes of cans; Changing temperature of heating in hot 
wells; Failure to react with sodium bicarbonate; Reducing amount of bicar- 
bonate; Seasonal variations in the coagulating point; Efi'ects of sterilizing 
temperatures upon nitrogenous constituents; Changes in viscosity at various 
stages of manufacture; The function of shaking and its influence upon the 
viscosity; Resterilization and its influence on viscosity; Detection of spoils; 
Factors influencing the quality; Factors influencing the color; Acidity in the 
various stages of manuf actvu'e ; Influence of freezing temperatures; Viscosity 
as related to feathering or curdling; Effect of cooling on color and viscosity; 
Gases in evaporated milk cans. 

CHAPTER XX 722-80'J 

Score Cards for the Dairy Industry: Development of the score card; Milk 
inspection question sheet; Score cards for sanitary inspection of farms, milk 
distributing plants, stores; Veterinarian's score card; Score cards for certified 
milk, milk, skim-milk, cream, butter, culture, buttermilk, cheese, cottage 
cheese, Swiss cheese, limburger cheese, ice cream, condensed whole milk and 
skim-milk, evaporated milk and powdered milk products. 

CHAPTER XXI 810-848 

Definitions and Standards for Dairy and Related Products: Standards of 
the United States Department of Agriculture for dairy products, sugar, cocoa 
products and flavoring extracts; State standards for composition; State 
standards for bacteria; Statistics on milk and cream regulations in cities 
and towns; Grading milk and cream. 



xvi Contents 

CHAPTER XXir 84'J-8(34 

Miscellaneous Information Regarding Dairy Products: Flow sheets; 
Temperatures for holding, manufacturing and storing; Action of milk on 
metals and certain properties of metals and alloys; Action of condensed and 
evaporated milk upon tin and iron; Heat transmission of metals, alloys 
and glass. 

APPENDIX 8G5-888 

Constants of the Elements; Conversion of degrees centigrade to degrees 
Fahrenheit, or vice versa; Specific gravity corresponding to degrees Baume 
for liquids lighter than water and liquids lieavier than water; Degrees 
Twaddell with corresponding specific gravity; Properties of saturated 
steam; Converting U. S. weights and measures cvistomary to metric; 
Metric to customary; Miscellaneous equivalents of metric weights and 
measures; Equivalents of metric weights and British Imperial weights and 
measures, metric to Imperial and Imperial to metric; Alcohol tables; 
Capacities of cylindrical tanks; Composition of different mamalian milks. 

Index of Proper Xames 8<Jl-89;j 

Index of Subjects 895-90<J 

Index of Figiu'es xvii-xxi 

Index of Tables. xxiii-xxviii 



Illustrations 



Fig. 1. Floor plan for laboratory in plant manufacturing various 

dairy products 8 

Floor plan for laboratory in plant manufacturing ice cream. 8 

Variation in fat and solids not fat in milk 13 

Fat globules in whole milk 18 

Fat globules in ice cream mix 18 

Fat globules in ice cream mix after homogenizing 18 

Solubility of milk sugar in water at various temperatures. ... 24 

Crystals of milk sugar 26 

Crystals of sucrose 26 

Milk sugar crystals 27 

Citric acid crystals 31 

Saving of time upon fat tests by Alojonnier method 43 

Results by jMojonnier and Babcock methods upon whole milk 50 

Saving of time upon total solids tests by Mojonnier method 59 

Model A Mojonnier Milk Tester 62 

M odel D Mojonnier Milk Tester 63 

Model G Mojonnier Milk Tester 63 

The Mojonnier Milk Tester with enumeration of parts 64 

Phantom view of fat side of Mojonnier Milk Tester 68 

Dimensions of Mojonnier Milk Tester 69 

Wiring diagram of thermostatic control of Mojonnier Milk 

Tester 72 

Analytical balance 7^ 

Analytical chainomatic balance 74 

Mojonnier Composite Sample Bottle 80 

Milk thief 81 

Milk sampling dipper 81 

McKay milk sampler 81 

Butter sampler 81 

Cheese sampler 81 

Method of obtaining drip sample of milk 83 

Composite sample bottle water bath 85 

Fat extraction flask 93 

Fat dish • 93 

Weighing cross with rubbers and pipettes 94 

Weighing pipettes with holder 95 

Position of weighing pipette before placing in holder 95 

Flask hanger with flask 96 

Flask hanger 96 

Butter boat 97 

Adding reagents 97 

Holder with llasks in position for adding reagents 98 

Correct position of flask when shaking 98 

Position of holder while shaking flasks 99 

Correct position when pouring ether solution into dish 100 

[ xvii ] 



Fig. 


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xviii Illustrations 

Fig. 45. Dividing line before and after raising in fat extraetion flask. . 100 

Fig. 46. I'^vaporating the ether 101 

Fig. 47. Transferring dishes to vacuum oven 102 

I'^ig. 48. Placing dish upon the balance pan 102 

Fig. 49. Valve handles controling vacuum in fat and solids ovens... 103 

Fig. 50. I'^illing water tank in Mojonnier Milk Tester 104 

h'ig. 51. I'^illing vacuum pump with oil 104 

Fig. 52. Placing calcium chloride in cooling desiccators ; . . . 104 

Fig. 53. Laboratory report blank 105 

Fig. 54. Solids dish 120 

Fig. 55. Weighing the solids sample 121 

Fig. 56. Dish contact maker 122 

Fig. 57. Cross diagram method for standardizing cream 148 

Fig. 58. Cross diagram method for standardizing milk 149 

Fig. 59. Fvaporated milk laboratory report 168 

Fig. 60. Blank report for evaporated milk 169 

Fig. 61. Green Gauge 171 

Fig. 62. Specific gravity of ice cream mixes at different temperatures 

and for different compositions 177 

Fig. 63. Pan striker for attaching to the waist of the pan 178 

Fig. 64. Pan striker for attaching to outlet of pan 178 

Fig. 65. Hydrometer cylinder 175 

Fig. 66. P)aumc hydrometer 179 

Fig. 67. Jacketed copper tank. 180 

Fig. 68. Glass enameled tank 181 

Fig. 69. Blank report for sweetened condensed milk 225 

Fig. 70. Specific gravity of sweetened condensed milk at various tem- 
peratures and compositions 228 

Fig 71. Relation of specific gravity and composition in sweetened 

condensed skim-milk at various temperatures 232 

Fig. 72. Pycnometer cup 233 

Fig. 73- I'.quipment for making sweetened condensed milk using 

Mojonnier process 235 

I""ig. 74. ]\Iilk sugar crj'stals in sweetened condensed milk of good 

crystalline quality 236 

Fig. 75. Milk sugar crystals in sweetened condensed milk of poor 

crystalline quality 236 

Fig. 76. Sweetened condensed milk cooler 237 

Fig. 77. Sweetened condensed milk cooler 237 

Fig. 78, Sweetened condensed milk cooler 238 

Fig. 79. Scale showing relative diameters of smooth and coarse 

texture water crystals '. 300 

Fig. 80. Per cent of frozen crystals 300 

Fig. 81- vSpecific gravity of various compositions of ice cream mix at 

different temperatures 304 

Fig. 82. Tee cream mix and cost report 307 

Fig. 83. Ice cream batch mixer 308 

Fig. 84. Ice cream batch mixer 308 

Fig. 85. Ice cream batch mixer 309 

Fig. 86. Ice cream batch mixer 309 

Fig. 87. Tee cream holding tank 309 

Fig. 88. Ice cream batch mixer 310 



Fipf. 


89. 


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90. 


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91. 


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Il,IvUSTR.\TIONS XIX 

Diagram showing graphic method of standardization 418 

Relation temperature, specific gravity and compositon in 

condensed whole milk 436 

Relation temperature, specific gravity and composition in 

condensed skim-milk .■;■■■■.■ '^ 

Relation temperature, specific gravity and composition in 

condensed buttermilk 438 

The four phases in the normal freezing of ice cream 444 

Influence of composition upon the freezing of ice cream... 448 
Influence of the sugar content of the mix upon the overrun 

in ice cream 450 

The mfluencc of aging upon the overrun in ice cream 451 

Manton-Gaulin Homogenizer 453 

Progress Homogenizer 454 

Viscolizer 455 

Suggested location of Mojonnier Overrun Tester in the 

freezer room 464 

Removing wire and rod from scale beam of overrun tester 466 

Leveling scale on overrun tester 466 

Filling dash pot w'ith oil 466 

Dash pot in cross section 467 

Adjusting movement of pointer 468 

Phantom view of scale 469 

Adjusting the overrun cup for any composition of mix.... 470 

Fmptying overrun cup into freezer hopper 471 

Adjusting telescopic bottom upon overrun cup 471 

Filling overrun cup with ice cream at the freezer 472 

Scraping overrun cup level full of ice cream 473 

Making reading for overrun 473 

Blank for recording overrun readings 474 

Microscope with names of various parts 477 

Microscopic substances found in milk 486 

Bacillus subtilis 495 

Bacillus subtilis with spores 495 

Streptococcus lacticus 524 

The relation between time of incubation and acid develop- 
ment in the growth of culture 526 

Influence of quantity of culture used upon acid develop- 
ment in media ^-^ 

Increase in titratablc acidity, using 15 cc. and 40 cc. of cul- 
ture to 750 cc. of media 528 

Influence of holding temperature of cultures upon the 

growing qualities of the same ^30 

Mojonnier Culture Controller 532 

Mojonnier Culture Controller in cross section 533 

Sterilizer to be used with Mojonnier Culture Controller... 534 

Culture jar 537 

Culture pipette 539 

Buttermilk machine 544 

Buttermilk machine 545 

Pfaudler buttermilk machine 546 

Buttermilk machine 547 



XX Illustrations 

Specific gravity chainomatic balance 554 

Specific gravity bottle 555 

Sprengal tube 556 

Westphal balance 557 

Quevenne lactometer 558 

Baume hydrometer 558 

N. Y. Board of Health lactometer 559 

Relation between B. of H. lactometer, Quevenne lactometer 

and speciiic gravity scales 560 

Mojonnier-Doolittle Viscosimeter 567 

Mojonnier-Doolittle Viscosimeter dial 568 

Tube for Hart casein test 569 

Kjedahl apparatus for single nitrogen determination 571 

Polariscope and tube for sugar solution 589 

Nafis acidity tester 601 

Wizard sediment tester 605 

Wisconsin sediment tester 605 

Troy salt test apparatus 615 

Hunziker salt test apparatus 617 

Troy moisture tester for cheese 623 

Melting point apparatus 625 

Abbe-Zeiss Refractometer 627 

Distilling apparatus 629 

Lovibond Tintometer 645 

Specific heat determination apparatus 651 

Specific heat of several dairy products 654 

Hortvet Cryoscope 658 

Casein coagulating apparatus 661 

Apparatus for making electrometric titrations of solutions 

containing protein 675 

60. Pounds of water evaporated per hour per square foot of 

heating surface 686 

Mojonnier type vacuum pan 687 

Straight type wet vacuum pumps 691 

Piping scheme suggested for vacuum pan 693 

Factors that influence heat transmission 713 

Device for breaking whirlpool in jacketed hot well 714 

Fort Wayne Sterilizer 720 

Berlin Sterilizer 721 

Sterilizer arrangement when using hot water in sterilizing 723 
Relation between coming-up time, holding temperature, 
holding time and cooling time in sterilizing evaporated milk 724 

Mojonnier Fvaporated Milk Controller 725 

Average seasonal variations in the coagulation point of 

evaporated milk 753 

Viscosity of evaporated milk 756 

Fort Wayne Shaker 757 

Berlin Shaker 758 

Calcium citrate taken from cans of evaporated milk 762 

General flow sheet of milk 849 

Flow sheet of pasteurized whole milk 850 

Flow sheet of pasteurized cream 850 



Fig. 


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Fig. 


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159. 



I-Ig. 



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FiR. 


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176. 


Fig. 


177. 


Fig. 


178. 



Illustrations 



Fig. 179. Flow sheet of butter niannfacture at centralized creamery 850 

Fig. 180. Flow sheet of bulk condensed milk manufacture 851 

Fig. 181. Flow sheet of evaporated milk manufacture 851 

Fig. 182. Flow- sheet of sweetened condensed milk manufacture.... 851 

Fig. 183. Flow sheet of ice cream manufacture, Method 1 852 

Fig. 184. Flow sheet of ice cream manufacture, Method 2 852 

Fig. 185. Flow sheet of ice cream manufacture, Method 3 852 

Fig. 186. Flow sheet of cheddar cheese manufacture 853 

Fig. 187. Flow sheet of cream and skim-milk powder manufacture.. 853 

Fig. 188. Flow sheet of whole milk powder manufacture 853 

Fig. 189. Flow sheet of casein and milk sugar manufacture 854 

Fig. 190. Flow sheet of milk chocolate manufacture 854 

Fig. 191. Flow sheet of culture buttermilk manufacture 854 

Fig. 192. Parts per million of metallic lactates required to impart a 

definite taste to water 857 

Fig. 193. The influence of the acid content of milk upon the solubility 

of metals 859 



Index of Tables 

Table 1. The water, fat and solids not fat content of dififerent dairy 

products derived from a certain whole milk 11 

Table 2. Distribution of constituents of whole milk 15 

Table 3. Solubility of milk sugar at different temperatures 25 

Table 4. Fat percentages obtained by different methods 41 

Table 5. Effect of using varyitig amounts of reagents 47 

Table 6. Content of whole milk as found by three methods 51 

Table 7. Comparison of fat tests by Mojonnier, Adams and Bab- 
cock methods 51 

Table 8. Comparison of fat tost of skim-milk by Mojonnier and Bab- 
cock methods 52 

Tabic 9. Comparison of fat test of sweetened condensed milk by 

Alojonnier method ; 52 

Table 10. Comparison of fat test of buttermilk by Mojonnier and 

Babcock methods 53 

Tal)Ie 11. Comparison of fat test of ice cream mix by Mojonnier and ' 

Babcock methods 54 

Table 12. Composition of fat column in Babcock test bottles 56 

Table 13. Total solids found by formula and by gravimetric method. 59 

Table 14. Total solids test upon evaporated milk 60 

Table IS. Total solids test upon sweetened condensed milk 60 

Table 16. Dimensions and specifications covering the Mojonnier Milk 

Tester ." 68 

Tabic 17. Influence of temperature upon the weight of aluminum 

dishes 77 

Table 18. Influence of tem]K'rature upon weights of various objects. 77 
Table 19. The distribution of water in. and loss of water by evapora- 
tion from, a cheddar cheese 89 

Table 20. Laboratory report 105 

Table 21. Summary of operations on the Mojonnier Milk Tester. .116-118 

Table 22. Per cent S. N. V. and T. S. in cream 134 

Table 23. Quantity of skim-milk to use in standardizing whole milk. 150 

Table 24. Standardization of fat in cream 151 

Table 25. Constants for evaporated milk 165 

Table 26. Speciflc gravitv of evaporated milk testing 780% fat and 

25.50% T. S. ." 172 

Table 27. Specific gravitv of evaporated milk testing 8.00% fat and 

26.15% T. S.' 172 

Table 28. Relation of temperature to specific gravity in evaporated 

milk 173 

Table 29. Relation between specific gravity and composition in 

evaporated milk 175 

Table 30. Per cent of fat and S. N. F. in the proper ratio to stand- 
ardize evaporated milk 182 

Table 31. Per cent of fat. S. N. F. and T. S. in evaporated milk after 

condensing 185 

[ xxiii ] 



xxiv Index of Tables 

Table 32. Constants for sweetened condensed milk 221 

Table 33. Specific gravity at various temperatures of sweetened con- 
densed milk 226 

Table 34. Relation temperature to specific gravity in sweetened con- 
densed milk 226 

Table 35. Relation temperature, composition and specific gravity in 

sweetened condensed milk 227 

Table 36. Relation specific gravity, composition and temperature in 

sweetened condensed skim-milk 229 

Table 37. Relation specific gravity, composition and temperature in 

sweetened condensed skim-milk 230 

Table 38. Unit relation of temperature to specific gravity in sweet- 
ened condensed skim-milk 231 

Table 39. Capacities and sizes of standard equipment for manufac- 
turing sweetened condensed milk, using Mojonnier process 234 
Table 40. Composition of partly skimmed sweetened condensed milk. 239 

Table 41. Composition of sweetened condensed milk 239 

Table 42. Percentage of fat, S. N. F. in tbe proper ratio to standard- 
ize sweetened condensed milk 241 

Table 43. Ratio between the pounds of total milk solids in the batch 
and pounds of sugar required, to make sweetened con- 
densed skim-milk 271 

Table 43a. Suggested composition of ice cream mixes 273 

Table 44. The physical and chemical properties and the nutritive ratio 

of ice cream mixes 277 

Table 45. Commercial factors as influenced by composition of ice 

cream mi.x 280 

Table 46. Influence of gelatin upon viscosit}' of water solutions 283 

Table 47. Air whipped into various solutions of gelatin 284 

Table 48. Name and description of flavors, fruits and nuts used in 

ice cream 287 

Table 49. Influence of temperature and size of crystals upon the 

solubility of milk sugar crystals 291 

Table 50. Influence of composition upon milk sugar crystallization.. 292 
Table 51 Influence of miscellaneous factors, upon milk sugar crystal- 
lization 293 

Table 52. Solubility of milk sugar in presence of other products 294 

Table 53. Separation of milk sugar from ice 295 

Table 54. Relative solubility of milk sugar at various temperature 

and in different media 296 

Table 55. Influence of gelatin upon the physical properties of ice 

cream 299 

Table 56. Number of bacteria per cubic centimeter in ice cream mix 

prepared in the vacuum pan 303 

Table 57. Keeping qualities of ice cream mi.x prepared in the vacuum 

pan 303 

Table 58. Approximate weight per gallon of water and of various 

dairy products 306 

Table 59. Approximate composition of products used in ice cream mix 313 

Table 60. A few combinations of cream and condensed milk 337 

Table 61. A few combinations of dairy products 338 

Table 62. Ice cream mixes made from sweetened condensed skim- 
milk and other products 355 



InhKx of TAr.i.TCs XXV 

Table 6.3. Ice cream mixes usina; sweetened condensed skim-niilk and 

other products 335 

Table 64. Ice cream mixes using sweetened condensed skim-milk and 

other products 356 

Table 65. Composition of ice cream mixes for which standardizing 

tables are given 357 

Table 66. Range of fat and S. N. F. in tables 358 

Table 67. Standardizing table for ice cream mix testing 8.00% fat 

and 33.00% T. S 2>67-?>72 

Table 68. Standardizing tal)lc for ice cream mi.x testing 8.00% fat 

and 34.00% T. S i7i-2,7^ 

Table 69. Standardizing table for ice cream mi.x testing 9.00% fat 

and 34.00% T. S 379-384 

Table 70. Standardizing table for ice cream mix testing 10.00% fat 

and 35.00% T. S 385-390 

Table 71. Standardizing tables for ice cream mix testing 12.00% fat 

and 35.00% T. S 391-396 

Table 72. Standardizing tallies for ice cream mix testing 12.00% fat 

and 36.00% T. S 397-402 

Table 7i. Standardizing tables for ice cream mix testing 16.00% fat 

and 38.00% T. S 403-408 

Table 74. Standardizing tables for ice cream mix testing 18.00% fat 

and 40.00% T. S 409-414 

Table 75. Ice cream mixes made from cream, evaporated milk, whole 

milk, sugar, gelatin and water 419 

Table 76. Ice cream mixes made from cream, condensed whole milk. 

whole milk, butter and sugar 420 

Table 77. Ice cream mixes made from condensed whole milk, whole 

milk, sugar, gelatin and butter 421 

Table 78. Ice cream mi.xes made from cream, condensed skim-milk, 

whole milk, sugar and gelatin 422 

Table 79. Ice cream mixes made from skim-milk powder, butter, 

sugar, gelatin and w-ater 423 

Table 80. Ice cream mixes made from cream, butter, skim-milk 

powder, whole milk, sweetened condensed whole milk, 

sugar and gelatin , . . . 424 

Table 81. Ice cream mixes made from cream, sweetened condensed 

skim-milk, butter, whole milk, sugar and gelatin 425 

Table 82. Ice cream mixes made from skim-milk powder, whole milk, 

butter, sugar and gelatin 426 

Table 83. Ice cream mixes made from sweetened condensed skim- 
milk, cream, sugar, gelatin and water 427 

Table 84. Ice cream mixes made from sweetened condensed milk, 

butter, sugar, gelatin and water 428 

Table 85. Ice cream mixes made from whole milk, butter, sugar and 

.gelatin to be condensed in the vacuum pan 429 

Table 86. Ice cream mixes made from whole milk, butter, sugar and 

gelatin to be condensed in the vacuum pan 430 

Table 87. Ice cream mixes made from skim-milk, butter, sugar and 

gelatin to be condensed in the vacuum pan 431 

Table 88. Per cent M. S. N. F. in T. S. of cream of different tests. . . 438 
Table 89. Composition of cocoa nibs, pure commercial cocoa and 

and cocoa shells 440 



Indi'X of TablKs 



Table 


90. 


Table 


91. 


Table 


92. 


Table 


93. 


Table 


94. 


Table 


95. 


Table 


96. 


Table 


97. 


Table 


98. 


Table 


99. 


Table 


100. 


Table 


101. 


Table 


102. 


Table 


103. 


Table 


104. 


Table 


105. 


Table 


106. 


Table 


107. 


Table 


108. 


Table 


109. 


Table 


110. 


Table 


111. 


Table 


112. 


Table 


113. 


Table 


114. 


Table 


115. 


Table 


116. 


Table 


117. 


Table 


118. 


Table 


119. 


Table 


120. 


Table 


121. 


Table 


122. 


Table 


123. 


Table 


124. 


Table 


125. 


Table 


126. 


Ta))lc 


127, 


Table 


128. 



Compo.'^ition of milk cliocolate 440 

Composition of mi.sccllaneous food products 441 

Correlation da?bcr speed, temperature incoming I)rine and 

mix and time required to freeze 459 

Influence of quantity of culture added to media 527 

Summary of experiment to determine influence of holding: 

temperature upon the growing^ qualities of cultures 531 

Range of Baume Lactometers with products upon which 

they are to be used 563 

Weight of sample recommended for lime determination.. 577 

Lime content of dairy products 578 

Volume of milk to be used frr sugar tk-termination 580 

Table for the determination of lactose ( Soxhlct-Wcin ) . . 582 

Munson and Walker table for calculation of sugars 587 

A comparison of results by White's method for sugar 

determination 588 

Percentage of citric acid recovered from milk products... 595 

Titratable acidity of various dairj' products 604 

Comparison of alcohol and acid tests 607 

Fat constants 626 

Rutyro-Refractometer readings and indices of refraction A 628 

The separation of gums 635 

1 dentilication of gums 636 

Spccilic heat of skim-milk 653 

Specific heat of whey 654 

Specific heat of butter 655 

Specific heat values for milk and milk derivatives 656 

Detection of water added to milk by freezing point method 657 
Ash and phosphorus content when coagulated at various 

intervals of time 664 

Hydrogen ion concentration expressed in form of hydro- 
gen ion normal 667 

Hydrogen ion concentration 672 

Intermediate p^j and Cjj equivalents for use with 

Table 116 673 

Relation of reaction colors to Pjj values 679 

Values of p,^ of phosphate solution 681 

Relation boiling points, vacuo and rate of evaporation... 685 

Capacity per hour" of various sizes of vacuum pans 690 

Sizes of vacuum pumps recommended for various sizes 

of vacuum pans 692 

Pounds of water re(|uircd to condense one pound of 

water vapor 695 

Percentage increase of water required, with incoming and 

outgoing condensing water at dififerent temperatures 697 

Percentage increase in volume in excess of water required 

when the pan temperature is 140° F 698 

Pounds of steam at various pressures condensed into 

whole milk 700 

Pounds of steam required to forewarm and condense raw- 
materials 702 

Relation of fuel consumption to steam production 704 



Index of Tables 



xxvii 



Table 129. Available heat units, volume and temperature of steam at 

various temperatures 708 

Table 130 Relation between temperature and time when coming up 

in sterilizers 722 

Table 131. Relation of titratable acidity and heat coagulation 726 

Table 132. Influence of acid content upon the coagulating temperature 

of milk 728 

Table 133. Effect of period of lactation on the percentages of albumin. 

casein, and total protcid in milk 729 

Tabic 134. Influence of added salts on the coagulating point of evap- 
orated milk 730 

Table 135. Balance between calcium and citrates 733 

Table 136. A sample in which calcium prevents coagulation 734 

Table 137. Relation between concentration of evaporated milk and 

its acid content 734 

Table 138. Efifect of rennet forming bacteria on curdling temperatures 726 

Table 139. Determining steam distribution in the sterilizer 739 

Table 140. Relation temperature, scale reading and coming up-time. 742 

Table 141. Correcting viscosit}' of evaporated milk to 75° F 744 

Table 142. Evaporated milk that failed to react to bicarbonate of soda 749 

Table 143. Percentage of each protein constituent 754 

Table 144. Viscosity changes in products used to make evaporated 

milk 755 

Table 145. Influence of shaking on viscosity 758 

Table 146. Changes in viscosity of evaporated milk under different 

storage temperatures 759 

Table 147. Titratable acidity in evaporated milk! at various stages... 765 
Table 148. Comparison of curdling efifect of coffee and water on 

evaporated milk 768 

Table 149. Color and viscosity of evaporated milk under different 

methods of cooling 769 

Table 150. Solubility of CO. in water 770 

Table 151. State and territorial standards 824 

Table 152. Grouping of cities and regulations available for study... 828 

Table 153. Regulations relating to water 829 

Table 154. Regulations relating to total solids 829 

Table 155. Regulations relating to solids not fat 830 

Table 156. Regulations relating to fat in milk 830 

Table 157. Regulations relating to bacteria in milk 831 

Table 158. Regulations relating to fat in cream 831 

Table 159. Regulations relating to tuberculin test 831 

Table 160. Regulations relating to bacteria in cream 832 

Table 161. Regulations relating to temperature 832 

Table 162. Regulations relating to specific gravitj^ 833 

Table 163. Regulations relating to water supply 833 

Table 164. Regulations relating to milkers 833 

Table 165. Conditions which render milk legally unsalable 834 

Table 166. Regulations in regard to parturition 836 

Table 167. Regulations relating to milk house 837 

Table 168. Regulations relating to milk utensils 838 

Table 169. Regulations relating to city milk plants 839 

Table 170. Regulations relating to dclivt*ry wagons 839 



XXVlll 



IndKx Of Tables 



Table 171. Regulations relating to the milk 840 

Table 172. Regulations relating to the scoring of dairy farms 840 

Table 173. Temperatures for holding, manufacturing and storing 

dairy products 855 

Table 174. Influence of temperature upon the solubility of metals 

in milk 858 

Table 175. Comparison of metallic lactates required to impart taste, 

and of metal actually dissolved 861 

Table 176. Conductivity or heat of certain metals, alloys and glass.. 863 
Table 177. Degrees Twaddell with corresponding specific gravity. . . . 865 

Table 178. Constants of the elements 866 

Table 179. Specific gravit}' corresponding to degrees Baume for 

liquids lighter than water 870 

Table 180. Specific gravity corresponding to degrees Baume for 

liquids heavier than v.'ater 872 

Table 181. Properties of saturated steam 874 

Table 182. Conversion of U. S. weights and measures. Customary 

to metric 876 

Table 183. Conversion of U. S. weights and measures. Metric to 

customary 877 

Table 184. Conversion of metric and British Imperial weights and 

measures, Metric to Imperial 878 

Table 185. Conversion of metric and British Imperial weights and 

measures. Metric to Imperial 879 

Table 186. Conversion of British Imperial and metric weights and 

measures, Imperial to Metric 880 

Table 187. Miscellaneous equivalents of metric weights and measures 882 
Table 188. Conversion of degrees Centigrade to degrees Fahrenheit, 

or vice versa 883 

Table 189. Alcohol table for calculating the percentages of alcohol in 

mixtures of ethyl alcohol and water from their specific 

gravities 884 

Table 190. Capacities of cylindrical tanks 887 

Table 191. Composition of milk from dififerent mammals 888 



LIST OF ABBREVIATIONS 

c. p. = Chemicall}^ pure 

c. c. or cc. = Cubic centimeter 

m. = Centimeter 

mg. = JMilligram 

gm. = Gram 

mm. z= ^Millimeter 

^"^^m. — ■ Centimeter """^ 

b. p. =: Boiling point 
F. = Fahrenheit 
C. = Centigrade 

=: Inches 

— Feet 

Lbs. = Pounds 

1^- S. = Total solids 

M. S. N. F. = ^lilk solids not fat 

S. N. F. = Solids not fat 

T. M. S. = Total milk solids 

T. S. N. F. = TotaJ solids not fat 

B. of H. = New York Board of Health Lactometer 

N. = Normal solution 

N/10 or 0. IN = Tenth-normal solution 

B. T. U. =: Biitish Thermal unit 
Sp. H. = Specific heat 

° R. = Degrees retardation 

c. r= Small calorie 

C. =T. Large calorie 

Sq. cm. =T Square centimeter 

E. M. F. =r Electro motive force 

PH = Hydrogen ion concentration 

^H = Hydrogen ion normal acid solution 

^OH- = Hydrogen ion normal or normal alkaline solution 

A. O. A. C. = Association of Official Agricultural Chemists 

Sp. Gr. = Specific gravity 

IL = Baume 

R- = Bacillus 




^, 



s 



u 






"o 






tt) 



CHAPTER I 
THE DAIRY PLANT LABORATORY 

The testing laboratory in a dairy plant does not generally 
receive the consideration that its importance warrants. This is 
so because it is of recent development, and the proprietors of 
many dairy plants do not yet fully realize the economical value 
of the -work. As they become more conscious of the fact that the 
composition of a marketable dairy product has a large influence 
on fixing its value and that the composition cannot be accurately 
determined without suitable accommodations and equipment, the 
laboratory and its work will receive as much consideration as 
other important operations in the manufacture of milk products. 
The loose methods in operation during the development of the 
industry will not prove successful under the present system of 
keen competition, and just as no business can hope to operate 
successfully for any length of time without an efficient system of 
accounting so a dairy manufacturing plant cannot hope to operate 
successfully without accurately determining the composition of 
each product received and distributed. The possibility of pre- 
venting loss through thorough control methods is of such im- 
portance that no reasonable detail should be overlooked in 
equipping the laboratory. 

Location. The laboratory should be a separate room located 
near the office and where practical, should have direct communi- 
cation with the manufacturing rooms. It should be used solely 
for analytical work and the chemist should not be annoyed or 
distracted by persons passing through it, nor by the conversation 
of others present. Where these precautions are observed valuable 
time may be saved, the work will proceed more rapidly, and the 
liability for mistakes to occur and consequent losses will be re- 
duced to a minimum. The air in most dairy manufacturing 
plants as a rule is exceedingly moist due to escaping steam, wet 



\ 

\ 

\ 



2 The Dairy Plant Laboratory 

floors, and the large amount of water constantly us'ed for clean- 
ing purposes. Since excessive moisture is injurious to sensitive 
and delicate apparatus and makes accurate work more difficult, 
the laboratory should be located in the driest part of th-'j building. 
Moist walls, escaping steam and wet floors should be avoided as 
much as possible. 

Floor. A smooth floor that does not absorb moistui-e, and 
which may be easily and thoroughly cleaned serves best. Water 
from adjoining rooms should not be allowed to flow into the 
laboratory. Ample drains should be supplied to carry away wash 
water. Asphalt on a concrete base is very satisfactory, but any 
substantial floor will serve. The floor and walls should be solid 
and free from vibrations as they will have to support chemical 
balances, and other delicate apparatus that should rest on solid 
foundations in order to prevent their injury, and give the beist 
service. 

Ventilation. The ordinary means of ventilation, where pos- 
sible, should be supplemented by forced draft. This may be 
readily supplied and serve a double purpose by placing a flue 
leading from the hood. Proper ventilation will assist materially 
in freeing the laboratory of excessive moisture, noxious gases 
that should not be allowed to enter the manufacturing rooms, and 
in contributing to the health of the workers. 

Temperature. The temperature should be held at all times as 
near to 68" F. (20° C.) as is convenient. Wide changes in tem- 
perature are to be avoided because of the efl'ect upon the ap- 
paratus and upon the density of solutions. 

Tables and Desks. The laboratory tables should be substantial 
and covered with material impervious to moisture or chemicals. 
Where expenses must be kept down wooden tops stained black 
and treated with acid and alkali proofing substance are commonly 
used. Sheet lead laid over plank is favored by some and is pre- 
ferred to wooden tops. Glazed white tile or slabs of vitrolite give 
good service, and are very neat and attractive. Any finish that 
cannot be easily and thoroughly cleaned, or which is softened by 
heat should be avoided. While wooden drawers give good 
service, metal drawers made from pressed steel are an advantage 
because they do not swell nor check under varying atmospheric 



Equipment 3 

or moisture conditions. Ample drawer space for storing ap- 
paratus should be provided under the benches and tables. The 
drawers should vary in depth from three to ten inches according 
to the apparatus they are to contain. The larger enclosed spaces 
under the benches should be reserved for the taller pieces of 
apparatus. Narrow shelves for holding reagent bottles should be 
placed on the walls over the work benches. Cupboards for hold- 
ing chemicals should also be supplied. 

Hood. No laboratory is complete or satisfactory without a 
roomy well ventilated hood. It should be equipped with sliding 
sash front to permit observation of operations Avithout opening 
the hood. Where available the hood as Avell as the work benches 
should be supplied with gas and water cocks. 

Sinks. The sinks should be large and conveniently located as 
much work must be done near them. Iron or porcelain sinks are 
to be preferred, and where they are to be used to carry away 
mineral acids, they should be lined with sheet lead, and the waste 
pipes should also be made of lead. Where possible the sinks 
should be supplied with hot as well as cold water. The plumbing 
should be so constructed that it may be readily reached when 
repairs are necessary. 

Steam and Electricity. Both steam and electricity can be 
used in many ways to advantage in the testing laboratory. Where 
power for operating a large amount of equipment is installed, it 
will be a comparatively simple detail to supply the laboratory. 
While it is not always indispensable, electricity is coming more 
into general use in laboratory methods, and in many analyses it 
is a real necessity. 

Lighting". Good light is a real necessity in laboratory work. 
A large skylight opening toward the north serves well, and where 
the location of the room permits, this means of lighting should 
be adopted. It should be supplemented with side lights where 
possible. The best light is obtained through north windows, but 
light from other directions will serve fairly well. The laboratory 
should also be provided with a good system of artificial light as 
it will be needed on dark days, and in the morning and late after- 
noon of the shorter days. White or light colored walls will also 
issist materially in giving good light. 



4 The Dairy Plant Laboratory 

Apparatus. The larger and more important pieces of ap- 
paratus are the Mojonnier tester, balances, polariscope, micro- 
scope, viscosimeter, centrifuges, water-still, drying ovens, hot 
water bath, extraction apparatus, and muffle furnace. 

The Microscope. A good microscope is an essential piece of 
apparatus in every dairy plant laboratory. Where bacteriological 
work is carried on, it is an absolute necessity, and it will be 
frequently used in the examinations of milk sediment for dis- 
tinguishing yeasts and molds and detecting milk sugar crystals 
in condensed milk and other milk products, and for the study of 
butter fat globules. For these reasons the chemist should have 
a good microscope with all accessories immediately available. 

The following are the more important of the small, necessary 
items of equipment for a completely equipped dairy laboratory: 

Balance, Harvard trip, or torsion. Sensitive to 1/100 gram. 

Balance, specific gravity. 

Beakers, glass, 100 c.c, 250 c.c, 500 c.c. 

Beakers, aluminum, 150 c.c. 

Beaker covers (watch glass). Difl'erent sizes. 

Bottles, reagent. Glass stoppered, 250 c.c, 500 c.c, 1000 c.c. and 2000 c.c. 

Bottles, washing, with rubber stopper and flexible delivery tube. 

Bottles, weighing. 

Boxes, microscope slide. 

Brushes, wooden handles for cleaning cylinders and jars. 

Brushes, camel's hair for cleaning scale pans. 

Brushes, on tinned iron wire handle for cleaning long tubes. 

Burettes with glass stopcock. Capacity 10 c.c. and 50 c.c, graduated 

to 1/10 c.c. 
Burettes, Mohr's. For pinch cock. Capacity 50 c.c, graduated to 

1/10 c.c. 
Burners, alcohol lamps, glass. 
Burners, Bunsen. 
Burners, Bunsen's ring form. 
Centrifuges, high speed, with accessories. 
Clamps, burette Lincoln. 
Clamps, Universal for condensers, etc 

Clamp holders. For attaching clamps, extensions, rings, etc. 
Clamp test tube. 
Clamps, tubing. 

Condensers, with bulb condensing tube, used in perpendicular position. 
Condenser, with straight condensing tube, used in slanting position. 
Connecting bulb tubes, Kjeldahl's. 
Corks, best quality, various sizes, 



Equipment 

Corks, rubber. 

Cork borers of polished brass, 12 in nest. 

Cork borer, sharpener. 

Cork softener, 

Cork screw. 

Cotton for plugging test tubes. 

Crucibles, glazed porcelain, with covers. 

Crucibles, Gooch. 

Gooch crucible holder, Bailey's. 

Crucible, platinum with cover, capacity 15 c.c. 

Crucible tongs. 

Cylinders, for use with hydrometers and lactometers. 

Cylinder, graduated 10 c.c, 25 c.c, 100 c.c, 1000 c.c. 

Desiccators, one large, one small. 

Dishes, crystallization, fiat bottoms. 

Dishes, evaporating, porcelain. 

Forceps, fine straight points. 

Drying oven, double walled for water. 

Extraction apparatus, heaters for. 

Files, round (rat tail). 

Files, triangular. 

Filter paper, various sizes. 

Filter paper, ash free. 

Filter cover, porcelain. 

Filter pump. 

Flasks, ordinary form. 

Flasks, Erlenmeyer, 125 c.c, 250 c.c, 500 c.c. 

Flasks, distilling. 

Flasks, for suction filtration. 

Flasks, Kjeldahl digestion. 

Flasks, sugar, accurately graduated at 100 c.c. and 110 c.c. 

Flasks, graduated at 250 c.c, 500 c.c. 

Funnels, glass, different sizes. 

Funnels, separatory. 

Funnel tubes. 

Furnace, muffle, for all kinds of muffle work. 

Glass rods. 

Glass tubing, various diameters. 

Hydrometers, specific gravity and Beaume scales. 

Lactometer, Quevenne. 

Milk sediment tester and accessories. 

Mortar, agate or porcelain with pestle. 

Pipettes, small with rubber bulb. 

Pipettes, volumetric, 5 c.c, 10 c.c, 25 c.c, 50 c.c. 

Ring stands, iron. 

Rings, support with clamp. 

Rubber policemen. 



6 The Dairy Plant Laboratory 

Rubber ttibing. 

Sand bath, of iron. 

Shears, laboratory. 

Sieves, meSh, 20, 60, 80, ]00, 140, 180. 

Spatulas. 

Supports, burette, condenser and funnel. 

Test tubes, 10 c.c, 25 c.c, 50 c.c. 

Test tube racks. 

Test tube baskets. 

Thermometers. 

Tripods. 

Triangles, wire, and pipe stem. 

Tripods, iron for Bun sen burners. 

Tubes, connecting. 

Tubes, distilling. 

Watch glasses. 

\^'ater bath. 

^Vire gauze. 

Wire gauze, iron with asbestos center. 

Additional Apparatus for Bacteriological Work. 
Autoclave. 
Sterilizers. 

Dry air sterilizing oven. 
Incubator. 

One c.c. pipettes, graduated in tenths. 
Test tubes, heavy walled. 
El-lenmeyer flasks, 1000 c.c. 
Petri dishes, 100 x 10 mm. 
Reading glass. 
Counting plate. 
Counter. 
^Vax pencils. 

The following are the more impoitant chemicals required in a completely 
equipped dairy laboratory: 

Acid acetic, glacial 99.0%. 

Acid hydrochloric C. P. concentrated :J8.0%. 

Acid nitric C. P. concentrated 69.0%. 

Acid oxalic C. P. crystallized. 

Acid rosolic. 

Acid sulphuric C. P. concentrated 100%. 

Alcohol, amyl. 

Alcohol, ethyl, absolute Sp. Gr. .7938, and also 190° proof, 95%, 

Alum (potassium aluminum sulphate) crystallized. 

Ammonia, concentrated 28%. 

Ammonium chloride. 

.\mmonium molybdate, 



General PivANs 

Asbestos fibre. 

Barium chloride. 

Chlorinated lime, crystallized. 

Calcium peroxide. 

Carbon bisulphide. 

Cochineal, indicator. 

Copper sulphate, crystallized. 

Distilled water. 

Ether, moisture and residue free, both ethyl and petroleum. 

Ferric chloride. 

Formaldehyde, 40%. 

Fuchsin, crystallized. 

Glycerin, U. S. P. 

Potassium iodide. 

Lead acetate (crystallized). 

Litmus paper and cubes. 

Magnesium carbonate. 

Mercury. 

Methyl orange. 

Phenolphthalein. 

Potassium carbonate. 

Potassium hydrate sticks. 

Potassium permanganate. . 

Pumice stone. 

Eoehelle salts (crystallized sodium and potassium tartrate). 

Silver nitrate, C. P. crystallized. 

Sodium carbonate. 

Sodium hydrate, sticks. 

Starch. 

Tumeric, dry powder and paper. 

Xylol. ; 

Zinc dust. 

Tenth— normal sodium hydroxide. 

Tenth — normal hydrocliloric acid. 

Tenth — normal ammonium hydroxide. 

Tenth — normal silver nitrate. 

Saturated lime water. 

GENERAL PLANS FOR DAIRY LABORATORIES. 

No fixed plan can be recommended to suit all plants. Th 
conditions prevailing at each separate plant must be taken into 
consideration before deciding upon the arrangement and equip- 
ment of the laboratory. Fig. 1 shows the suggested floor plan 
for a plant laboratory where a number of different dairy products 
are manufactured. Under some conditions it might be desirable 



e 



The; Dairy Plant Laboratory 




Pig". 1. Sug-g-ested floor plan for laboratory in plant manufacturing- several 

different dairy products, including- evaporated milk, sweetened 

condensed milk and ice cream. 

1. Mojonnier milk tester. 2. Evaporated milk controller. 3. Washstand. 
4. Autoclave. 5. Sterilizer. 6. Incubator. 7. Hood. 8. Work bench. 
9. Babcock tester. 10. Desk. 11. Chair. 




18-0"- 



Fig-. 2. Sugg-ested floor plan for laboratory in plant manufacturing ice cream. 

1. Mojonnier milk tester. 2. Washstand. 3. Autoclave. 4. Sterilizer. 
5. Incubator. 6. Work bench. 7. Hood. 8. Desk. 9. Chair. 



General Plans 9 

to divide the work into departments, and to partition the labora- 
tory into separate rooms. The arrangement of the control 
laboratory where such is maintained will be governed by the 
work to be done therein, and in many respects can be considerably 
different, both as regards arrangement and equipment, from the 
plant laboratory. Fig. 2 shows the suggested floor plan for a 
small factory laboratory where only ice cream or a limited num- 
ber of other dairy products are manufactured. The equipment 
in this case can be reduced to a minimum, being limited to ap- 
paratus for controlling fat and total solids and where so desired, 
for making bacteriological and a few other minor tests. 



CHAPTER II 
THE CONSTITUENTS OF MILK 

General Statement. Milk is the normal secretion of the mam- 
mary glands of mammalia during the period of lactation fol- 
lowing parturition. The definition of milk, adopted by the 
Association of American Dairy, Food and Drug Officials, Aug. 3, 
1917, was the following: "Milk is the whole, fresh, clean, lacteal 
secretion obtained by the complete milking of one or more healthy 
cows, properly fed and kept, excluding that obtained within 15 
days before and 5 days after calving, or such longer period as 
may be necessary to render the milk practically colostrum free." 

The milk of a number of different species of mammalia has 
been used as human food. In parts of the world the milk of the 
zebu, goat and sheep is of some commercial importance. Goat's 
milk in some instances has found favor in this country as food 
for infants of delicate digestion, probably because the casein does 
not readily mat into a lump when acted upon by acids in the 
stomach. The casein in that respect behaves more like the casein' 
in human milk. However, the substance commercially known 
as milk in this country, refers to the milk of the cow, and it is 
used in this sense in this volume unless otherwise specified. 

THE PHYSICAL PROPERTIES OF MILK. 

Milk and the products obtained from milk are so universally 
used that their principal physical properties are a matter of com- 
mon knowledge. Whole milk consists of an emulsion of light- 
yellow fat globules in an opaque white serum that usually has a 
slight bluish tinge. The color of whole milk as well as of other 
dairy products varies under many different conditions, both of 
production and manufacture. The practice of standardizing color 
is a long established one in man.y industries. Physical properties 

[10] 



Composition 



11 



Hi 



!«| 
« S 

O o 

a> 

■s.s 






Skim- 
milk 
Powder 


o 
o 




o 


OS 


ol 
o 

id 


1 

in 

00 




Whole 

Milk 

Powder 


8 


o 


in 

o 


o 

o 

id 


05 
IN 




o 


«oro 3-3 »* « 


8 

00 


T-l 


8 

CO 


O 

00 

CO 


3. 2 j;""'fe M 

9^2-00:5 

rH «4-i ra CO 




O 


o 
00 


o 


o 

lO 

id 

IN 


00 




Plain 
Bulk 
Con- 
densed 
Whole 
Milk 


8 

d 


o 
o 

00 


o 

o 

IN 
(N 


8 

d 

CO 


CO 

00 
CO 




Plain 
Bulk 
Con- 
densed 

Slum- 
milk 


o 
•o 


IN 


IN 

id 

(N 


o 

if3 

id 

IN 


i> 

CO 




Sweet- 
ened 
Con- 
densed 
Whole 
Milk 


com 3 


o 
o 

00 


O 

o 


o 
in 

CO 


S *^ 0) ii d c 




O 

o 

TO 
03 


o 


o 
-*< 

d 


o 
d 


05 

cn 
00 


Cheese 

(Fresh 

American 

Cheddar) 


8 

00 

CO 


o 
o 

d 

C<3 


IN 


o 
o 

(N 

CO 


o 


1:^ 
1' 


00 

d 


O 


00 


d 








o 

o 

d 


O 

o 

00 


o 
o 


00 


Tfl 




s 

cs 

o 


CO 


o 

o 

d 


00 
TO 

id 


00 
CO 

lO 


Ol 




I1 


00 

o 


o 


IN 

00 

00 


IN 

00 


OJ 

o 




1- 


N.' 

00 


TO 


o 

lO 

00 


lO 
M 

IN 


o 
o 
o 






Constituents 


1- 
i. 




« 
fe 


■** 

o 

ca 

12 
1 

ii 


12 

o 


'a-i:^ 3 g 





12 Constituents of Milk 

such as flavor, viscosity and appearance that frequently affect 
the sale of the product also vary under many different condi- 
tions. It is not within the province of this chapter to discuss 
these properties in detail. Further reference will be found in 
later chapters. 

THE COMPOSITION OF MILK. 

The constituents of milk and milk products divide themselves 
into groups both for commercial and scientific considerations. 
First: Water and total solids (ordinarily at least no attempt is 
made to account for the gases in milk). Second: The total solids 
are divided into two parts, one being called fat and the other 
solids not fat. Both of these later groups form the basis of our 
leading dairy industries. Third : The solids not fat are again 
further divided into their several component parts which will be 
described in later paragraphs. 

In Table 1 the composition is given of our most common 
American dairy products, in terms of water, fat, solids not fat, 
and total solids. It is assunied that the initial lot of whole milk 
weighed 1000 pounds, and that it tested 87.75 per cent of water ; 
3.75 per cent of fat; 8.50 per cent of solids not fat, and 12.25 
per cent of total solids. It is further assumed that the entire lot 
of products mentioned in the table were obtained from a similar 
quantity and composition of whole milk. The pounds of each 
kind of product thus obtained is given. Note the remarks in the 
case of sweetened condensed milk and in ice cream mix. The 
yield and composition of these products as mentioned could not 
have been obtained except by removing part of the fat in the 
case of the sweetened condensed milk, and by adding additional 
fat in the case of the ice cream mix. 

VARIATIONS IN CONTENT OF FAT AND SOLIDS NOT FAT IN 

WHOLE MILK. 

The composition of milk varies considerably, and the per- 
centage of no single constituent is constant between samples 
taken from different sources or different milkings of the same 
individual. The range of variation that occurred in the percentage 
of fat and in the percentage of solids not fat in the milk from 
1217 herds is shown in Fig. 3. 



Composition 



13 










Tig, 3. Variation in fat and solids not fat in milk from 1217 Kew York Herds 
Tests made by H. C. Troy and W. B. White. 



14 Constituents of Milk 

It also shows the general relation that exists between the per- 
centages of fat and solids not fat. The data represent the com- 
position of single samples of the mixed herd milk from 1217 
different herds. They included the different breeds and classes 
of cows in central and western New York. The number of cows 
in the different herds is not known, but would probably average 
about ten. The samples were taken at all seasons of the year 
from the mixed herd milk by inspectors, experienced in such 
work, after watching the milking operation and making certain 
that the samples truly represented the milk produced by the herd 
at that milking. Several hundred of the samples were analyzed 
by one of the authors of this book, while he was State Chemist 
in New York, and the remainder were made by his successor, 
Mr. W. B. White, State Chemist, Ithaca, New York. 

The fat varied between 2.25 per cent in the lowest analysis 
to 6 per cent in the highest. The solids not fat varied between 
7.25 per cent in the lowest analysis to 10.13 per cent in the highest. 
The percentage of solids not fat increases as the percentage of 
fat increases, but the ratio of increase is not constant and gradu- 
ally diminishes as the higher fat percentages are reached. 

The percentage of fat was obtained by the Adams extraction 
method excepting in a few cases where the Babcock method was 
used. The solids not fat were obtained by drying to constant 
weight 2.5 to 3.0 grams of milk in a flat bottomed platinum dish 
in a water-jacketed drying oven containing boiling water, and 
then subtracting the percentage of fat from the percentage of 
total solids. 

DISTRIBUTION OF CONSTITUENTS OF WHOLE MILK. 

Table 2, next page, was prepared to show at a glance the per- 
centage composition of each important class of constituents in 
whole milk, and likewise of the separate constituents making up 
the various classes. 

The various constituents are discussed both by groups and 
also individually in the following paragraphs. 

Gases. In the majority of dairy products, the material gases 
contained therein are of no practical or commercial significance. 
Gases are frequently the product of decomposition in which event 
they become undesirable constituents, and may cause large com- 



Composition 



15 



mercial losses, principally in the case of butter, cheese and 
sweetened condensed milk. In other prociiicts such as Koumiss, 
the development of carbon dioxide is of prime importance, and 
determines the commercial value of the product to a considerable 
extent. The principal gases found in fresj^ily drawn milk are 
carbon dioxide, oxygen and residual gases, \ generally assumed 
to be nitrogen, but this assumption remains uiVproved. The total 
volume amounts to about 7 to 9 per cent. According to Mar- 
shall's experiments, the above gases are present an the milk before 
the same leaves the udder. i 

TABLE 2. 
Distribution of Constituents of Whole Milk. \ 



?^^ 



Glycerides of 
insoluble and 
non-volatile 
acids 



Olein 33.95 

Palmatin 40.51 

Stearin 2.95 > 

Myristin 1 0.44 

Laurin 3.57 , 

Butyrin 6.33 ^ ^.i a c 

•' (jflvcerides of 

^^P^°^" 2.32Loiu^j^ ^„d 

^^P^y^"^ • -^M volatile acids 

Caprinm .34 j 

f Casein 3,60 ^ 

Albumin 60 Nitrogen 

Globulin traco \ containing 

Fibrin trace substances 

Lecithin 05 J 



[-3.40% ^ 



0.30% 



3.25% 



3.70,% ] 



T. S. 

> 12.35% 



Milk sugar 
Citric acid . 



.4.50% 
.0.20% 



Ash 



.0.70% 



Solids 
) not fat 

Potassium oxide .1751 8 65'/ 

Sodium oxide 070 

Calcium oxide 140 

Magnesium oxide .... .017 

Iron oxide .001 

Sulphur trioxide .027 

Phosphorus pentoxide . . .170 
Chlorine 100 

Water 87,65'% 



Total 100.00% 



16 Constituents of Milk 

Water. The water forms about 87% of the milk substance. 
It is derived directly from the blood and serves as a vehicle for 
carrying the other constituents of the milk in a fluid condition. 
The water may be separated from the other substances by dis- 
tillation. It may then be condensed and collected. After remov- 
ing traces of volatiJe gases, it has exactly the same composition 
and physical properties as pure water from any other source. 

Total Solids. The total solids include all of the milk con- 
stituents that are not evaporated when a small amount of the 
milk is spread over a large surface and dried to practically con- 
stant weight at a temperature of 100° C. The percentage of total 
solids may vary between 10.5 and 15.5. In a few exceptional 
cases it may fall outside of this range, but in the vast majority 
of analyses it will fall between 11.5% and 13%. The percentage 
of total solids in milk or other dairy products is of special im- 
portance as it is a measure of the food substance contained 
therein, and also because legal enactments have fixed minimum 
percentages of total solids for most dairy products. 

Solids Not Fat. The solids not fat are made up of casein, 
sugar, albumin, ash, and a few other less abundant, but neverthe- 
less important constituents. They form the solids in the serum 
after the fat has been removed. The white, opaque color of milk 
is largely due to their presence although the fat globules add to 
this property. In milk of average composition, the solids not 
fat supply about one-half of the energy producing substances 
and practically all the muscle building properties. The higher 
specific gravity of milk over that oi' water, is also due to these 
substances ; the specific gravity of the solids not fat being about 
1.615. They increase the viscosity (sticky quality) of milk, and 
as some of them are not in complete solution, they assist in hold- 
ing the fat in an emulsified state, preventing its rapid rise to the 
surface, and complete separation from the remainder of the fluid 
under the influence of the force of gravity. Even when force is 
applied in centrifugal m.ethods of separation, the solids not fat 
prevent the removal of some of the smaller fat globules so that 
separator skim-milk rarely contains less than .05% of fat. 

Van Slyke and Bosworth^ state that sugar, citric acid, potas- 
sium, sodium and chlorine are wholly in solution, and that the 



Milk Fat 17 

albumin, inorganic phosphates, calcium and magnesium are partly 
in solution and partly in suspension. Any of these substances 
that are in suspension would assist in holding fat in an emulsified 
condition. 

Skim-milk, buttermilk, whey, plain and sweetened condensed 
skim-milk and skim-milk powder owe their commercial im- 
portance to their content of milk solids not fat. The small amount 
of fat carried in these products also adds to their value. There 
is everywhere a growing recognition of the food value of milk 
solids not fat. 

Milk Fat. The fat from milk is generally known as it appears 
in butter. For this reason it is commonly called butter fat. Be- 
fore it is separated from milk it may be seen, with the aid of a 
microscope, in the form of minute opalescent globules floating in 
the milk serum. Different investigators have determined the 
diameter of the fat globules of milk. While their results are 
not wholly in accord, it appears that the diameters of the globules 
vary between 0.01 mm. and 0.0015 mm. (approximately 0.004 and 
0.00006 inch). The fact that fat globules of milk do not readily 
unite, combined with other phenomena, led to the theory at one 
time supported by some investigators, that the globules are sur- 
rounded by a membrane, but there is scarcely evidence sufficient 
to support this conclusion. The consensus of opinion among in- 
vestigators is that the fat exists in the milk in the form of a 
true emulsion. 

The appearance of butter fat globules under the microscope 
varies with the product, and with the treatment which the product 
has received. 

"When fat is completely separated from the milk in the form 
of butter, it is characterized by its yellow color, and by desirable 
and attractive flavors and aroma. Animal fats may appear some- 
what yellow especially when melted to an oil, and by selecting 
the fats from certain parts of the carcases of cattle of some breeds, 
tallow may be obtained that has a yellow tint when solid, but 
the depth of yellow color in butter is not obtained in tallow, 




Fig-. 4. Fat Globules in Whole Milk. Mag'. 500 Sia. 

Courtesy Telling-Belle "Vernon Company 





Fig-, 5. Fat Globules in Ice Cream Before Homog-eniziug-. Mag-. 200 Dia. 

Courtesy Telling-Belle Vernon Company 




Fig-. 6. Fat g-lobules in Ice Cream Mix After Homogenizing. Mag. 200 Dia. 

Courtesy Telling-Belle Vernon Company 



Milk Fat 19 

without the addition of foreign coloring. The yellow color of 
milk fat may vary according to the individual cow, the breed and 
the feed. The fat having the more pronounced yellow color is 
produced in the early summer, when the food is green and suc- 
culent, while the palest fat is produced in the winter months when 
such feed may not be obtained. The color of the fat in the form 
of butter is somewhat intensified by the addition of salt. 

Fig. 4 shows fat globules in whole milk. Fig. 5 shows the 
fat globules in ice cream mix before homogenizing, and Fig. 6 
after homogenizing. 

The melting point of milk fat varies between 31° and 36^ C, 
(88° and 96° F.). A number of factors combine to influence the 
melting point, but the exact effect of each is not known. The 
specific gravity of milk fat ranges between .93 and .94 at 15° 
C. (59° F.). The fat expands as the temperature is increased, 
thus lowering the specific gravity until at a temperature of 60° 
(140° F.) it is about .90, and at 100° C. (212° F.) it is approxi- 
mately .864. 

Milk fat is composed of 9 different fats. Browne- made a study 
of the percentage of each present and obtained the following 
results. 

Palmatin 40.51%, olein 33.95%, myristin 10.44%, stearin 
2.95%, laurin 2.73%, butyrin 6.23%,, caproin 2.32%, caprylin 
53%, caprinin 34%. 

The fats are composed of three elements, carbon, hydrogen 
and oxygen. The atoms of these elements combine with each 
other under the force of chemical attraction to form molecules. 
The substances made up of these molecules possess different prop- 
erties according to the proportion of each element present, and 
the manner in which the atoms are combined. Combined in one 
way and one proportion, they form the well known substance 
called glycerine ; combined in another way and in differing 
proportion, they form a series of substances called fatty acids. 
In the elaboration of milk fat in the body of the animal nine 
distinct fatty acids are formed and combined with glycerine. 
Each molecule of glycerine holds three fatty acid radicles in com- 
bination. The acids present in milk fat are butyric, caproic, 
caprylic, lauric, myristic, palmitic, oleic and stearic. Combined 



20 Constituents of Milk 

with glycerine they form the nine fats named above. It appears 
that any three of the fatty acids may unite with a glycerine 
radicle, thus forming a more complex molecule than would be 
possible if the glycerine molecule were combined with three 
radicles of a single fatty acid. 

The fat molecules may be split up into glycerine and fatty 
acids. By separating the glycerine and purifying it, the ordinary 
glycerine of commerce is obtained. When set free from the 
glycerine the butyric and caproic acids are soluble in water while 
the other fatty acids from milk fat are not soluble. The fatty 
acids of milk fat may also be grouped as volatile and non-volatile. 
When a mixture of fatty acids in water is boiled the butyric, 
caproic, eaprylic, capric and possibly some of the lauric acids are 
volatilized. By means of a distilling apparatus they may be col- 
lected and measured by titration with an alkali. 

This is one of the best methods of distinguishing milk fat 
from all other fats and oils as the percentage of volatile fatty 
acids in the latter is much lower. It is the presence of the fats 
from the volatile fatty acids, especially butyric, that gives butter 
its characteristic flavor. The fat in butter becomes rancid as a 
result of the splitting up of the fat molecule, as the fatty acids 
when freed from the glycerine radicle have very characteristic 
and pungent odors and flavors. 

The percentage of the harder fats is lowest during the earlier 
stages of the lactation period with a corresponding increase in the 
percentage of the softer fats. This has a practical bearing as the 
softer butter resulting retains moisture more readily than the 
harder butter made from fat secreted toward the end of the period 
of lactation. The manufacturing process must be modified to 
meet these difi'ering conditions or butter containing a percentage 
of moisture above the legal limit may result. 

Both from a physiological and commercial standpoint, the fat 
is the most important constituent of all dairy products. Thi? 
accounts for the exact control required over this constituent. 

Casein. Casein is the principal protein of milk, and it is 
present in the milk of all mammalia. It has been studied by a 
number of investigators, and different names have been given to 
the substance as it exists in fresh milk, and to the principal 



Casein 21 

product derived from it iu the natural souring of milk. Van Slyke^ 
states that the neutral substance as it is believed to exist in 
fresh milk is calcium caseimate, consisting of casein iu combina- 
tion with 1.5% of calcium oxide. The true casein consists of the 
protein that remains after it has been separated from the calcium 
oxide. The name calcium paracasein is given to the insoluble 
substance formed by the action of rennet. 

The casein forms about 80% of the milk proteins, the albumin 
about 15%, and small amounts of other proteins make up about 
5%. It appears that some of the same influences that affect the 
percentage of fat in milk, also may cause variations in the per- 
centage of casein. 

Casein is present in fresh sweet milk in the form of minute 
gelatinous particles satvirated with the remainder of the serum 
until the substance is evenly distributed throughout the mass of 
liquid. Substances that act in this manner are called colloids. 
The colloidal particles of casein do not pass through animal 
membrane or unglazed porcelain and may be separated from 
skim-milk by using these substances as filters. The calcium casein 
separated from skim-milk by this means, is a gelatinous substance 
nearly white in color. It is not quite as opaque as the casein pre- 
cipitated from milk by acids, and is not so readily ground to a 
white powder when dry. 

The casein molecule has a very complex structure being made 
up of a large number of atoms. The six elements that enter into 
its composition, and the percentage of each according to 
Kirchner* is carbon 53%,, hydrogen 7%, oxygen 22.70%, nitrogen 
15.70%, phosphorous .85%, sulphur .75%. 

Pure casein may be separated from fat-free milk serum by 
precipitation with very dilute acid. Special precautions must be 
taken to prevent other milk constituents from contaminating the 
casein during the operation, and to wash it free from foreign 
substances before drying. 

In the natural souring of milk, the lactic acid which is de- 
veloped from the milk sugar, unites with the calcium of the 
calcium caseinate, forming calcium lactate, setting free the casein 
and precipitating it, in the form commonly seen in curdled milk. 
The precipitation of the casein begins when the acidity reaches 



22 Constituents of Mii.k 

about .6% at 70° F. if the acid is developed normally in the milk. 
If the acid is added to the milk at a temperature of 70° F. a 
slightly lower percentage will coagulate the casein. The higher 
the temperature, the lower will be the percentage of acid neces- 
sary to cause coagulation. Casein is also coagulated by the salts 
of a number of metals and by concentrated alkaline solutions ; 
while dilute alkaline solutions and concentrated acid solutions 
dissolve it. Heat changes- the casein compounds in fresh milk 
under pressure and coagulates the casein at 130 to 140° C. The 
enzymes, rennin and pepsin also precipitate casein and are used 
extensively for this purpose in the manufacture of cheese. The 
specific gravity of casein is between 1.26 and 1.35. 

Casein serves primarily as a food as it is found in milk, and 
the usual milk products. It forms a large part of the substance 
of nearly all cheese, and gives to cottage cheese practically all 
of its food value. In some proprietary foods the casein is treated 
with sodium compounds, and other salts that are also found in 
milk, and other substances to make it more soluble or to give it 
special properties. Plasmon, Tila, Nutrose, Eucasein, Sanatogen, 
Lacto-Somatose and Argonin are trade names given to foods of 
this nature made from casein. 

Galalith and Lactoform are substances made from casein 
after precipitation with metallic salts, or by other means and then 
treated with formaldehyde. This substance may then be used for 
some purposes as a substitute for, or in imitation of bone, horn, 
ivory, celluloid, porcelain and similar materials. It is used in the 
manufacture of buttons, door knobs, knife handles, picture frames, 
tubes, rods, oil flasks, cartridge cases, sink plugs and corks. 

It is mixed with medicinal reagents to assist in administering 
them, and it is used in many massage creams, ointments and soaps. 
Glues, adhesives, putties, paints, calcimine, photographic mate- 
rials, glazing materials, dolls and toys are also sometimes made 
from it. It is also further used in calico printing, in making imi- 
tation leather, insulating material, washable oil paper, drawing 
and writing paper, and in treating cloth and felting, and loading 
silk and other cloth, to make them heavier. 

Milk Sugar. Milk sugar or lactose forms about 38 per 
cent of the total solids. The percentage present in milk from 



Milk Sugar 23 

different sources, and from different milkings of the same animal 
does not vary over nearly as wide a range, as does the percentage 
of fat. It is composed of carbon, hydrogen and oxygen. Three 
modifications of milk sugar are known to exist, all of which be- 
have differently towards polarized light. 

First, the monohydrate or a milk sugar which has the formula 
Cj2 H„2 Oil -|- HoO. This is the ordinary crystallized milk sugar 
of commerce, and the form that crystallizes out from water 
'solutions at room temperature. As the formula shows, it contains 
one molecule of water of crystallization. This water is retained 
upon heating to 100'' C. in the dry state, or in water in an un- 
saturated solution. At 130° to 140° C. the molecule of water is 
given off. At 170° C. it decomposes forming lacto-caramel. It 
melts at 203.5° C. with further decomposition. Its specific heat 
is 0.30 and its specific gravity is 1.54. 

Second, the anhydrous modification called [i anhydrous milk 
sugar Avhich has the formula Cj, Hjo On. Hudson" devised a 
method whereby this modification could be produced in a chemi- 
cally pure condition. His method is based upon the principle 
that this form crystallizes out of hot, supersaturated solutions 
of milk sugar. The specific gravity at 20° C. is 1.59. 

Third, another anhj^drous modification called a anhydride 
which is obtained when the monohydrate milk sugar is heated at 
125° C. to constant weight. This form is very hygroscopic, and 
the evidence indicates that, upon dissolving in Avater, it goes 
back to the monohydrate form. 

The solubility of milk sugar has been studied by Dubrun- 
faut,"' C. S. Hudson," E. Soillard," Mack & Liedel,'' and in the 
laboratory of Mojcnnier Bros. Co. Milk sugar has both an in- 
itial and a final solubility. That is, by mixing an excess of milk 
sugar with water, a certain amount will go immediately into so- 
lution, and a further additional amount will also go into solu- 
tion, after prolonged mixing of milk sugar with water. It is 
this fact that accounts for the disagreement in results between 
different investigators. The final solubility at different tem- 
peratures is given upon the graph Fig. 7 and in Table 3, page 25. 



Constituents of Milk 




^^ff^7)i3yf^y^sJJ'yoja a// ^ynj. 



Mii,K Sugar 



25 



TABLE 3. 

The Solubility of Milk Sugar at Different Temperatures. 



Temperature 
degrees F. 


Parts milk 

sugar dissolved 

in 100 

parts water. 

11.9 


Temperature 
degrees F. 


Parts milk 

sugar dissolved 

in 100 

parts water. 


35 


120 


43.0 


40 


13.2 


125 


46.8 


45 


14.0 


130 


51.0 


50 


14.9 


135 


59.9 


55 


15.9 


140 


64.5 


60 


17:0 


145 


65.8 


65 


18.2 


150 


69.3 


70 


19.5 


155 


74.5 


75 


21.0 


160 


80.1 


80 


22.8 


165 


86.2 


85 


24.8 


170 


93.2 


90 


27.0 


175 


101.2 


95 


29.3 


180 


110.5 


100 


31.7 


185 


121.3 


105 


34.3 


190 


133.9 


110 


36.8 


192 


139.2 


115 


39.7 







As indicated by the foregoing results, the solubility decreases 
with lowering temperatures, or vice versa. The rate of solution 
increases rapidly with rising temperatures. Between 32° and 
35° F. the solubility increases at the rate of .17 parts of milk 
sugar to 100 parts of water for each degree F. of rise in tempera- 
ture. 

Between 190 and 192° F. the increase is at the rate of 2.65 
parts, or 15.6 times greater than at the lower temperature. 

The crystalline monohydrate of milk sugar according to 
Traube^^ belongs to the monocliuic system, and the same has the 
following constants : a, b, c = 0.3677 ; 1 : 0.2143, B = 109° 47'. 

The faces are clinodomes. 



26 



Constituents of Mii,k 



A typical crystal is illustrated under Fig. 8. For purpose 
of comparison, typical crystals of cane sugar are illustrated under 
Fig. 9. This shows the characteristic difference between the 
two sugars. 

Fig. 10 is a photomicrograph of milk sugar crystals crystal- 
lized from a pure lactose solution by evaporation of the water 
at room temperature. 

Milk Sugar, like cane sugar, as pointed out by Browne,-"' 
crystallizes in a variety of forms. This is proved by examination 
of the above photomicrographs. This accounts for the lack of 
agreement upon the subject between aiithorities. 




Tig, 8. 



Typical Monoliuic Crystal of Milk Suffar tlie faces of wliicli are 
clinodomes. 





Pig-. 9. 



Typical Monolinic Crystals of Sucrose, I. Tatoular Form, II. Porm 
with Hemihedral Paces.-" 



Decomposition Products of Milk Sugar. Through the action 
of lactic acid bacteria, milk sugar is converted into lactic acid, 
one molecule of sugar yielding four molecules of lactic acid, ac- 
cording to the following equation : 

C, H,, Oi,+H,0 = 4 C3He03. 
In actual practice the theoretical amount of lactic acid is 
not realized, as a part of the sugar is broken down to form other 
substances, the principal of which are carbon dioxide and water. 
Only about 70% of the sugar that disappears is found in the 
form of lactic acid. A part of the acid, thus formed from the 



Milk Sugar 27 

milk sugar, unites with the calcium, setting the casein free. The 
latter then coagulates and forms the curd of sour milk. 

When a little more than .20% of lactic acid has developed in 
milk its presence may be detected by its odor, and when the per- 
centage reaches .25% to .30% it is noticeable to the taste. "When 
.60%, of acid has developed in the milk the casein coagulates at 
ordinary temperatures, and when about .90% of acid has de- 
veloped the ordinary variety of lactic acid bacteria becomes in- 
active and the development of the acid_ ceases. Special forms 
of bacteria like those used in the manufacture of Yogurt (Bac- 
terium caucasium) develops acidity as high as 3%. 




Fig-. 10. Milk Sugrar Crystals. Magr. 200 Dla. 

Courtesy Telling-Belle Vernon Company. 

Milk sugar, when fermented by the action of certain special 
varieties of yeasts, also yields alcohol. With the presence of 
bacteria, lactic acid may be formed at the same time, and the 
casein is partly broken down. This form of fermentation is 
used in the manufacture of koumiss from mare's milk and kep- 
hir (or kefir) from the milk of cows, sheep or goats. Koumiss 
may develop as high as 3%' of alcohol and 1.25%, of lactic acid 
while kefir may contain a little more than 1% of alcohol and 
.9%; of lactic acid. 

Uses of Milk Sugar. Milk sugar is used to a large extent 
with cream and water in modifying cow's milk for feeding in- 
fants when it is desired to reduce the percentage of protein. 
Xt is supposed to have special value in checking undesirable fer- 



28 Constituents of Milk 

mentation in the digestive tract. It is sometimes used as a food 
for consumptives, and in cases of dropsy and wasting diseases. 
It also finds use in pharmacy as a base for pills, tablets and 
other similar purposes. 

The percentage of milk sugar in concentrated milk products 
like evaporated milk and condensed milk varies according to 
the degree of concentration of the milk, and the percentage 
originally present. The condensing process does not necessarily 
cause any change in the milk sugar unless it is exposed to high 
temperature^ for a long time, thus partially carmelizing the milk 
sugar and giving it a darker color. This, in turn, gives a very 
light brown color to the milk. Where the concentration of milk 
is carried to a point that does not leave enough water to hold 
the sugar in solution, it crystallizes out, and the concentrated 
product has a sandy and gritty feeling on the tongue when 
tasted. If such product is used in the manufacture of ice cream 
without pasteurizing and diluting, it sometimes transmits this 
undesirable property to the frozen product. A large part of 
the milk sugar in sweetened condensed milk is usually present 
in the crystallized form. It is not considered objectionable in 
this substance, especially if the crystals are small enough to re- 
main in suspension. 

Milk sugar may readily become the starting point for many 
defects in dairy products. For this reason its properties and 
its behavior under varying conditions require close study. 

Albumin. Milk contains about .6 per cent of this protein. 
Because it is not present in milk in such large amounts, and is 
not of such commercial importance, it has not received as much 
study by investigators as has been given to casein. It differs 
from casein in composition, and in several of its properties. It 
is in solution in milk, and it may be coagulated by heat above 
70° C. Acids do not coagulate it at ordinary temperatures and 
it is not coagulated by rennet nor by magnesium sulphate added 
almost to saturation. It contains no phosphorus, and about 
twice as much sulphur as casein. The albumin may be sepa- 
rated by boiling the liquid that remains after precipitating the 
casein from skim-milk with dilute acids or rennet, and filtering. 
The coagulated albumin will remain on the filter as a white 



Albumin 29 

amorphous mass which is not as granular as casein that has been 
coagulated by acids. 

Sebelien" prepared pure albumin from milk and gives it the 
following composition: Carbon, 52.19%; hydrogen, 7.18%- 
nitrogen, 15.77%,; sulphur, 1.73%; oxygen, 23.13%. 

Albumin contributes about one^sixth of the protein food 
value of milk and whole milk products that retain all of the 
milk constituents. The albumin' in the whey obtained in the 
manufacture of cheddar cheese, is sometimes coagulated by heat 
and skimmed off. It is then made into an Italian form of cheese 
that is known as Ricotte. In the process of manufacturing milk 
sugar it is necessary to remove the albumin from the liquid. 
This is accomplished by heating the liquid to coagulate the albu- 
min, then passing it through filter presses. The albumin col- 
lects on the press cloths. When removed from these it is used as 
chicken feed, or in the manufacture of fertilizer. 

Mineral Constituents. Milk yields about .75% of ash when 
dried and burned in a manner to prevent loss of mineral matter. 
The ash does not accurately represent the salts in the milk as 
they are changed in the process of burning, and their exact com- 
bination is not definitely known. They are in solution with the 
exception of a little less than one-half of the phosphorus, and 
about two-thirds of the calcium which are in suspension accord- 
ing to Soldner.i" 

He estimates that the salts are composed of the following 
substances in the proportions given here: 

Per Cent 

Sodium chloride 10 62 

Potassium chloride g 16 

Monopotassium phosphate 12.77 

Dipotassium phosphate 9,22 

Potassium citrate 5 47 

Dimagnesium phosphate 3 jl 

Magnesium citrate 4 O5 

Dicalcium phosphate 7 42 

Tricalcium phosphate g 90 

Calcium citrate 23 55 

Lime combined with casein 5. 13 

100.00 



v30 Constituents oi^ Milk 

In the ash the bases are united with phosphoric, hydrochloric, 
carbonic and sulphuric acids, and as oxides. It has been thought 
that the small amount of sulphuric acid present is derived from 
the sulphur contained in the protein. The mineral matter in milk 
varies between rather narrow limits. It appears to increase 
slightly as the percentage of sugar decreases and vice versa. The 
percentage of ash in naturally rich milk is usually higher than in 
poor milk. The percentage also increases in milk secreted toward 
the end of th^ period of lactation. There are very small amounts 
of other substances which would slightly affect the salts in solu- 
tion, but they are relatively not very important, as far as now 
known. 

Lecithin. This substance is found associated especially with 
milk fat, egg yolk fat and liver fat. It is also found to a limited 
extent in some other animal and plant cell material. It is some- 
times classed as a phosphorized fat and has the formula C44 H90 
O9 NP, It is a yellowish white solid, soluble in ether and alcohol 
and may be separated from other food substances by the use of 
these solvents. When the extracted substance is treated with wa- 
ter, it appears to absorb it, but apparently does not go into com- 
plete solution, remaining in the form of an opalescent emulsion. 
When treated with an alkali it yields fatty acids, phosphoric acid, 
and other substances. 

Experiments by Supplee^^ and by Cusick^^ indicate that the 
fishy flavor frequently found in butter is due to the tri-methyl- 
amine derived from decomposition products of lecithin. 

Vitamines. In the past few years, investigators have proved 
that milk contains certain substances popularly called vitamines 
which are essential to health and growth. As yet none of these 
substances has been isolated, nor has their chemical identity been 
discovered. At the present time authorities are agreed that at 
least three distinct vitamines exist in milk. This number is known 
from their functional differences, ascertained largely by the bio- 
logical method. Largely at the suggestion of McCullom^^ and his 
associates, these have been named fat soluble A, water soluble B 
and water soluble C or anti-scorbutic vitamine, respectively. 

Fat Soluble A is especially abundant in milk fat, egg yolk fat, 
and in liver and kidney fat. It is also found in leafy vegetables. 



VlTAMINES 



31 



Water Soluble B is found in the non-fatty part of milk. It is 
also found in the yolk of eggs and in the leaves of plants. Fat 
Soluble A and Water Soluble B are found in greater abundance 
in milk and its products than in any other foods known up to 
this time. This is one of the strongest reasons why milk and its 
products should constitute a generous part of the diet of human 
beings from infancy to old age. It has been found by long and 
careful research that these two vitamines are not affected, re- 
duced, or destroyed by any of the usual manufacturing processes 
used in the home or in the factory in the handling of milk and its 
products. Pasteurized milk, evaporated milk, sweetened con- 
densed milk, ice cream, milk powder, butter and cheese all contain 
the above two vitamines in great abundance. 

Water Soluble C or anti-scorbutic vitamine is the least abun- 
dant in milk of the three vitamines named above. Even fresh milk 
just as it comes from the cow is deficient in this vitamine, and in 
any event its shortage should be supplied through other sources. 
Fortunately Water Soluble C is quite abundantly distributed in 
nature. Oranges and tomatoes contain it in relatively large quan- 
tities, providing a cheap and abundant supply. The addition to 
the diet of the juice from these products, either fresh or sterilized, 
can be practiced to advantage even in early infancy. 




Pig-. 11. 



Citrio Acid crystals prepared from cow's milk. Aliout one-half 
actual size. Prepared by one of ilxe authors.^ 



32 ■ Constituents of Milk 

Citric Acid. This substance (H3 Cg H5 0^. HoO) or its salts is 
a normal constituent of milk. The amount in milk appears to 
vary but on the average about .20 per cent is probably present. 
It is a tri-basic acid and the crystallized calcium salt is sometimes 
found in evaporated milk. BartheP* states that by calculating 
the amount of alkali metals present in milk it is found that they 
are present in excess of the amount that would be satisfied by the 
chlorine and phosphoric acid and that investigations by Beau^^ 
lead to the conclusion that the amount of citric acid in milk is on 
an average .2 per cent. Crystals of citric acid prepared from 
cow's milk are illustrated in Fig. 11. 

Traces of a number of other substances such as adenine, 
guanine, silica, urea, iodine and lacto-giobulin are known to be 
present in milk. Babcock and Russell (1897)^^ found an enzyme 
called galactose that dissolves casein. It was prepared from cen- 
trifuge slime and its aqueous extracts possess proteolytic proper- 
ties to a considerable degree. It is most active in slightly alka- 
line solutions, and heat of 73° to 75° C. readily destroys it. The 
presence in milk of one or more proteolytic enzymes is now gen- 
erally accepted, although little is known of their composition. 
Fresh milk is sometimes amphoteric to litmus, that is, it changes 
red litmus paper slightly blue and blue litmus paper red. There- 
fore that indicator cannot be used in determining the acidity. 
This behavior of milk toward litmus is believed to be due to tho 
phosphates in milk, as some phosphate compounds in solution act 
in a similar way. Milk is acid to phenolphthalein, and this indi- 
cator is generally used in determining its acidity. The apparent 
acidity is largely due to salts of phosphorus which undergo a re- 
adjustment in the presence of an added alkali. 

The apparent acidity of fresh milk normally varies between 
.10 per cent and .18 per cent, but in exceptional instances he.s been 
found as high as .24 per cent, calculate'd as lactic acid. 

Rice^^ investigated the milk of individual cows ar.d found 
titratable acidities as high as .22%. High percentages of casein 
and solids not fat usually, but not alTv^ays, accompan.y high ap- 
parent acidity. Electrical conductivity and hydrogen concentra- 
tion did not differ from that of normal milk. Titration by the 
Van Slyke oxalate proc<idure indicated that phosphates were al- 



Reiferkncks 33 

ways somewhat higher in this class of milk. Mclnemey^® de- 
termined the amount of phosphates in samples of fresh milk 
from herds producing milk of high apparent acidity. In each 
instance the percentage of phosphates was high. 



REFERENCES. 

■ LY,^^ '^i7^®' ^- ^■' ^""^ Bosworth, A. W.: The Condition of Casein and Salts 
in Milk. Tech. Bui. No. 39, N. Y. State Agr. Exp. Sta., 1914. 

-Browne, C. A.: Jour. Am. Chem. Soc, 21, p. 807, 1899. 

» Van Slyke, L. L., and Bosworth, A. W.: Tech. Bui. No. 39, N. Y. State 
Agr. Exp. Sta., 1914. 

* Kirchner, W. : Handbuch der Milchwirtschaft, Berlin, 1898. 

"^ Dubrunfaut: Compt. Rend., Vol. 42, p. 228, 1856. 

•Hudson, C. S.: Journal American Chem. Soc, 1904 and 1908. 

'' Soillard, S.: Chemie et Industrie, Sept. 1919. 

"Mack & Liedel: Thesis. Ohio State University, 1920. 

"Sebelien: Zeitschr. f. Physiol. Chemie, 1885, Vol. 9, p. 445. 

'0 Soldner: Die Solz der Milch und ihre Beziehungen zu dem Verhalten des 
Kaseins. Die Landwirtsch. Versuchsstation, 1888, Vol. 35, p. 361. 

"Supplee, G. C: The Lecithin Content of Butter and Its Possible Rela- 
tionship to the Fishy Flavor. Memoir 29, Cornell Univ. Agri. Exp. Sta., 
Ithaca, N. Y., November, 1919. 

" cusick, J. T.: Phosphorus in Butter. Memoir 30, Cornell Univ. Agri., 
Exp. Sta., Ithaca, N. Y., April, 1920. 

"McCollum, E. v.: The Newer Knowledge of Nutrition. 

^^j^^* Barthel, Chr.: Milk and Dairy Products. Trans, by Goodwin, W. Lon- 

16 Beau: Revue General du Lait, Vol. III., 1904, p. 385. 
'"Babcock, S. M., and Russell, H. L,.: Unorganized Ferments of Milk, a 
dI^ 189 T^'" '" Ripening of Cheese, 14th, An. Rpt., Univ. Wis. Ag. Exp. Sta., 

•a^-JIo^'^r®', ^T ^d ^^st. of paper on apparent acidity of milk, Science, New 
Series, Vol. L., No. 1296, Oct., 1919. 

isMcInerney, T. J.: Unpubl. Exps., Dept. of Dairy Ind., N. Y. S. Coll. of 
Agr., Cornell Univ., Ithaca, N. Y. 
'^Traube: Jahrb. V-7, p. 430. 
A„ ""Browne: Reprinted by permission from Brown's "Handbook of Sugar 
Analysis published by John Wiley & Sons, Inc. 

-' Mojonnier, T. 



CHAPTER III 

HISTORY AND PRINCIPLES OF FAT 
AND TOTAL SOLIDS TESTS 

(A) FAT TESTS. 

The fat in milk and its products varies so widely, and milk 
and its products are so easily adulterated that the same are now 
bought and sold largely on a composition basis. Legislative en- 
actments in many countries fix minimum standards for composi- 
tion, while the value of dairy cows depends upon the fat percen- 
tage in their milk as well as upon the yield. Also difficulty has 
been experienced in attempting to determine the exact composi- 
tion of milk. For all of the above reasons, chemists devoted 
much study and labor to devising methods for accurately deter- 
mining the percentage of fat in milk and other dairy products. 
Great impetus was given to the work during the latter half of the 
19th century by the rapid growth of the dairy industry, and the 
introduction of the factory system whereby milk producers pooled 
their milk for manufacturing purposes. The large number of 
fat determinations necessary, and the system of manufacture in 
vogue, required that the method of analysis should be rapid as 
well as accurate. The increased knowledge of chemistry, and the 
establishment of many experiment stations with well equipped 
laboratories in Europe and America, made it possible for a corps 
of trained chemists to attack the problem. The need for 
accurate methods was imperative, both upon the part of 
the investigator and the dealer in dairy products. In the first 
case, inaccurate results would lead to inaccurate conclusions and 
to confusion. In the second case inaccurate results would lead 
to unsatisfactory commercial transactions and financial losses. 
As a result of these researches, a very large number of tests were 
developed. While many of the methods possessed considerable 
merit, a few were so satisfactory that the others did not come 

[34] 



Fat Tests 35 

into general use. The tests may be grouped under the following 
headings : 

A. Tests where chemicals are not used. 

B. Tests where chemicals are used with or without the as- 
sistance of centrifugal force. 

A. 

1. Cream Gauges. 

2. Fjord's Centrifugal cream test. 

3. Heeren's pioscope. 

4. Feser's lactoscope. 

5. The churn test. 

6. The oil churn test. 

B. 

1. Soxhlet's method. 

2. Short's method. 

3. Parsons' method. 

4. Failyer and Willard's method, 

5. Cochran's method. 

6. Adams' Paper coil method. 

7. The Rose-Gottlieb method. 

8. Neilson's Kaolin method. 

9. Liebermann-Szekely's method. 

10. Weibull's desiccation method. 

11. Bell's Maceration method. 

13. Richmond's Kieselguhr method. 

12. The Storch method. 

14. The Werner-Schmid method. 

15. The Ritthausen method. 

16. The Wanklyn method. 

17. The De Laval Lactorite. 

18. The De Laval Butyrometer. 

19. The LeflFman and Beam method. 

20. The Gerber method. 

21. The Russian Babcock method. 

22. The Babcock method. 

23. Sichler's Sin-Acid Butyrometer test. 

24. Lindstom's Butyrometer test. 

25. The Mojonnier method. 

This bare historical summary indicates the large amount of 
work which has been done upon this problem. The list as given 
could be further subdivided, inasmuch as the methods involve 
several different chemical and physical principles. The principles 
of all the tests now in use in various parts of the world were dis- 
covered during the decade between 1880 and 1890. 



36 Fat and Total Solids Tests 

The Babcock method, which has attained world wide fame, 
was first published in 1890. This method is so well known, and 
so fully described in several excellent books upon the subject, 
that it needs no further elaboration here. 

The Adams method was first published in 1885. This is an 
English method. It involves the extraction of the sample in a 
dry form with anhydrous ethyl ether. This method was consider- 
ably used, and upon certain dairy products it gives satisfactory^ 
results while upon others, particularly skim-milk and concentrated 
milk products, the results which it yields are sometimes greatly 
in error. It deserves to be classified as among the very best of 
the ether extraction methods. 

In 1888 Kose^ published the method with which his name is 
now associated. Like the Adams method, the principle was based 
upon the solubility of fats in ether. However, there was this 
fundamental difference. Adams made a dry extraction while 
Rose used a wet extraction. The operation was carried out by 
him as follows: 

About 20 grams of the milk are mixed with 2 c. c. of ammonia, 
then 45 c. c. of alcohol and 120 c. c. of a mixture of equal parts of 
ether and light petroleum are added. The mixture is shaken in a 
stoppered burette of 230 c. c. capacity. The volume of the ethe- 
real layer is read oflP, and 25 c. c. of it is evaporated in a tared 
flask, the fat being dried by aspirating dried air through the 
flask for 10 minutes, while heating in a glycerol bath at 90° C. 
The residue is then cooled and weighed, and the percentage of fat 
is calculated. An addition of 0.015% should be made for fat re- 
maining in the aqueous layer. The method was modified by 
Gottlieb and republished in 1892. It then became generally 
known as the Rose-Gottlieb method. 

Schreib, H. (1888),^ after having considerable experience with 
the Rose method, and after making special experiments with it 
on the dry residue, obtained the same amount of fat on the fourth 
day as on the first, whether the residue was preserved in paper 
as in Rose's experiments, or in the basins in which the evapora- 
tion took place. 

Gottlieb (1892)^ modified the Rose method by reducing the 
volume of milk to 10 grams and by reducing the volume of the 



RosE-GoTTuEB Me;thod 37 

alcohol to nearly that of the milk. The amount of each ether 
used was reduced to 25 c. c. and details of the method worked 
out and explained. He states that the method is trustworthy as 
shown by the results of many analyses made by the method, and 
by comparisons with other methods, and that it is easily and 
quickly carried out. The author made 30 analyses in one day, a 
number that should not be considered as a maximum. He further 
states that the cylinder employed for the analyses may also be 
used for estimating .fat in cream, butter and finely powdered 
cheese. 

Lang (1893)* compared the results secured with several of 
the wet extraction methods and states that they agree well. 

Weibull (1898)-^ shows that fat tests made by the Rose-Gottlieb 
method on separated milk and buttermilk check better where the 
samples are analyzed by different chemists than when other meth- 
ods are used and Kuhn (1898)® agrees with him. 

Popp, M. (1903)^ did considerable work on the Rose-Gottlieb 
method. He gives the principle of the method and enumerates 
the precautions to be taken. He with Siegfeld (1903) found that 
the method worked well with skim-milk and whole milk. 

A series of determinations were made on whole milk and skim- 
milk letting the ether-petroleum milk solution stand Yo, 1, 2, 3 
and 6 hours. The greatest effect due to time of standing Avas 
.02% for skim-milk and .07 per cent for whole milk. Tests were 
also run using ammonia solutions of varying strengths, but there 
was no visible effect on the determination. 

The revised Rose-Gottlieb method for whole milk, skim-milk 
and buttermilk is given by Popp^ as follows : Put 10 c. c. of milk 
in a 100 c. c. cylinder that is graduated to i/o c. c. Add in order, 
1 c. c. of ammonia of proper concentration, 10 c. c. of alcohol, 25 
c. c. of ether, 25 c. c. of petroleum ether. Shake after each addi- 
tion, let stand about an hour, draw off the ether-petroleum ether 
fat solution till only 1.5 c. c. of it remains in the cylinder. 

Using ether, wash the fat left in the pipette into the fat solu- 
tion, distill off the ether and petroleum ether and dry and weigh 
the fat as usual. Multiply the weight of fat found by 10 to give 
direct per cent. 

To simplify the method of removing the ether fat solution, 
Rohrig (1905)^ devised a graduated stoppered cylinder provided 



38 Fat and Total Solids Tests 

with a side tube and tap at the 25 c. c. mark. By means of this 
tap, an aliquot part of the ethereal solution may be drawn off into 
a weighed flask. The percentage of fat in butter may also be 
estimated by means of this apparatus, 

Thomsen (1905)^"' carried on experiments with the Rose-Gott- 
lieb method to estimate the fat in milk when proteins were pep- 
tonized, and the milk dried into a mixture of kaolin and barium 
carbonate. He secured practically the same results with the 
method as with the Adams method. The results agree moreover 
with those obtained by the Rose-Gottlieb method on the unpep- 
tonized milk, but are lower than the results obtained in unpep- 
tonized milk by the Adams method. 

In order to determine the saponifying effect of the ammonia 
on the fat in the Rose-Gottlieb method. Burr (1905)^^ experi- 
mented with emulsions of milk fat and water which, when an- 
alyzed by this process, yielded the amounts of fat originally 
weighed out, showing that no loss of fat due to possible saponifi- 
cation by the ammonia had taken place. He states that in the 
ease of milk, the risk of saponification is, moreover, still less, as a 
considerable portion of the ammonia combines with the casein. 

Gordon (1906)^- used Rohrig's modification of the Rose-Gott- 
lieb method for estimating the fat in eight samples of cream, 
twelve samples of milk and eight samples of skim-milk, and 
showed that trustworthy results may be obtained. He states that 
the proportion of ether to light petroleum ether is of importance 
and should not differ greatly from that originally recommended. 
If a mixture of 10 c. c. of ether with 50 c. c. of petroleum ether is 
employed, the results will be much too low. 

Barthel (1910)^^ gives a very thorough review of the best 
methods for determining the percentage of fat in milk. He di- 
vides the methods according to their character and application 
into main groups : scientific methods and practical methods. He 
places the Rose-Gottlieb method in the scientific group and re- 
views the work of a number of other investigators. He states 
that with whole milk the Rose-Gottlieb, and the extraction meth- 
ods give results which agree very closely, but with separated milk 
and buttermilk the former always shows higher values. The dif- 
ferences on an average, are .03 per cent for separated milk, and 
for buttermilk more, sometimes as much as 0.1 per cent. The rea- 



RosE-GoTTLiijB Method 39 

son for this lies simply in the fact that in the latter cases the fat 
is in a very finely divided state, and so cannot be extracted com- 
pletely after drying on some porous material. 

Kropat (1914)^'* applied the modification to the estimation of 
the fat in creams, butter and cheese. 

Richmond (1910)^" makes the following statement: "On the 
whole, the Gottlieb method is the best, though those due to Adams, 
Storch, Werner-Schmid, and Nell are little, if at all, inferior in 
accuracy. 

Meniere (1914)^*^ attempted to devise a method somewhat sim- 
ilar to the Rose-Gottlieb, and Woodman modified the method by 
reducing the amount of milk taken and the amount of reagents 
used. He also devised an apparatus for removing the ether fat 
solution. He states that all of the successful methods for deter- 
mining the fat by direct extraction from the milk itself involves 
the complete or partial solution of the casein. In the Rose-Gott- 
lieb method the casein, precipitated from the milk in very finely 
divided particles by the alcohol, is dissolved by the ammonia. The 
fat is dissolved by the ethyl ether, and the addition of petroleum 
ether is to render less soluble the milk sugar or other non-fatty 
solids which would be dissolved by ethyl ether alone. 

Balton^' gives a description of the Rose-Gottlieb method and 
states in his description of the Gerber method that "it is very ad- 
vantageous to read the tubes against some standard method of fat 
analysis, such a method is the Gottlieb process." 

In his excellent work on food analysis. Leach, 1913, after de- 
scribing his modification of the Babcock method for estimating 
the fat percentage in sweetened condensed milk, recommends the 
Rose-Gottlieb method when the accuracy of a gravimetric process 
is desired. It is the only test that he mentions in his directions 
for determining the percentage of fat in ice cream. 

In the United States probably the first user of the Rose-Gott- 
lieb method was the late Prof. G. E. Patrick, for many years the 
chief of the Dairy Laboratory, United States Department of Agri- 
culture, at Washington. It was largely through his efforts that 
the merits of this method were brought to the attention of the 
American chemists, and that its use became introduced in Amer- 
ican laboratories. 



40 Fat and Totai. Solids Tests 

Bigelow and Fitzgerald (1915)/^ chemists in the research 
laboratory of the National Canners' Association, collaborating 
with Govers, Mojonnier and Grinrod, chemists employed in the 
laboratories of separate condensed milk companies, made a com- 
parative study of the Babcock and Beimling methods and modi- 
fications of them, and of the Rose-Gottlieb method for determin- 
ing the percentage of fat in evaporated milk. The results of 
comparative tests in each of the four laboratories are given for a 
number of samples. In their comments on the Adams method, 
Bigelow and Fitzgerald state that "the error due to the fat ex- 
tracted from the coils and thimbles is partly compensated by the 
fact that the milk fat can never be extracted completely from a 
sample prepared by drying in this manner. The extraction of 
the milk fat continues for a number of days, and is practically 
never complete, and the double method of extraction by the 
Adams method has no advantage with evaporated milk." They 
found considerable difficulty in securing correct results with 
the Babcock method on evaporated milk. The trouble is attrib- 
uted to a change in the protein as a result of the heat of process- 
ing, rendering its solution more difficult, and thus preventing the 
complete separation of the fat. When used in the plant with 
evaporated milk that has not been sterilized, the results are bet- 
ter, but still are only approximate. 

In the summary of the experiment, it is stated that "the vari- 
ous modifications of the Babcock method are not sufficiently ac- 
curate to be depended upon for determining whether the evap- 
orated milk is up to standard. It is strongly advisable that the 
Rose-Gottlieb method be used for this purpose. If any of the 
modifications of the Babcock method be employed for evaporated 
milk, considerable allowance must be made for the inaccuracies 
of the method. Results obtained by any modification of the Bab- 
cock method are totally inaccurate unless the fat column is clear, 
with the meniscus at the bottom of the column perfect, and not 
distorted by either char or milky appearance." 

In Table 4 there is given the fat percentages that they ob- 
tained by different methods from a few samples of evaporated 
milk. 



RosE-GoTTLiEB Method 



41 



TABLE 4. 
Fat Percentages Obtained by Different Methods, 



Sample 
Number. 


Rose-Gottlieb 
method. 


Adams 
method. 


Babcock 
method. 


Beimling 
method. 


707 


8.16 


7.68 




8.18 


708 


8.03 


7.50 




8.03 


709 


7.67 


6.77 




7.67 


710 


7.69 


7.18 




7.77 


711 


7.77 


7.16 




7.69 


712 


7.89 


7.22 




7.81 


713 


7.42 


6.97 




7.38 


802 


8.62 


8.30 


8.60 


8.69 


807 


7.70 


6.77 


7.65 


7.75 


824 


8.56 


7.68 


8.25 


8.48 


834 


8.26 




8.15 


8.07 


836 


8.41 




8.35 


8.48 


830 


7.90 




• • • • 


7.78 


837 


8.07 




8.05 


7.92 


840 


8.40 




8.20 


8.25 



In this experiment the Babcock test was modified by taking 
nine grams of evaporated milk and adding ten c. c. of water. The 
test was then completed in the regular way, excepting that the 
reading was taken from the extreme bottom of the fat column to 
the bottom of the upper meniscus, multiplying the reading by 2, 
and adding a constant factor of 0.15. 

The Beimling test was carried out in a Babcock milk test bot- 
tle. Nine grams of the evaporated milk were taken ; 10 c. c. of 
water added, and thoroughly shaken. The Beimling test was 
completed in the regular way, and then read from the extreme 
bottom of the fat column to the bottom of the upper meniscus. 
The reading was multiplied by 2 and 0.25% deducted. 

The Rose-Gottlieb method as used in the experiment was car- 
ried out as follows : 

"Weigh from 4.5 to 5.0 grams evaporated or condensed milk 
into a Rose-Gottlieb tube, add water to make about 11 grams and 
add 154 to ly2 c. c. concentrated ammonium hydroxide and thor- 
oughly mix by shaking. 

"Add 10 c. c. of 95% alcohol and shake thoroughly. Fill up to 
the If.vel of the side tube with water, if necessary, and shake. Add 



42 Fat and Total Solids Tests 

25 c. c. ether and shake well for one minute. Add 25 c. c. petro- 
leum ether (B. P. below 65° C.), and shake well for one minute. 

"Allow tube to stand until layers separate well. Draw off ether 
fat solution as completely as practicable, and run it through a 
small, quick acting filter into a weighted flask. (Weighted by 
counterpoising, if not finished the day it is started.) 

"Re-extract liquid into tube just as before with 25 c. c. of each 
ether, shaking after each is added. Before the addition of the 
ether, a little alcohol may be added, and the contents of the tube 
mixed by shaking, to bring the layer of ammoniacal liquid close 
up to the outlet tube, for by repeated extractions, the surface of 
separation is low^ered. 

' ' Run the ether solution from the second extraction through the 
filter into the flask and wash end of spigot, filter paper, and the 
lower surface of the funnel, with sulphuric ether ; or better, with 
a mixture of equal parts of sulphuric ether and petroleum ether 
which has been allowed to stand for separation of water. 

"In the examination of cream, a third extraction is necessary, 
but with evaporated and condensed milk, the third extraction 
recovers only 0.02 or 0.03% fat and may be omitted. 

"Evaporate the ether slowly on a steam bath and dry fat in 
steam oven until its weight is constant. Weigh after one hour 
and then at half-hour intervals. As soon as the fat begins to 
gain in weight, stop drying and take the next previous weight. 
Increase of weight is due to oxidation after all moisture and alco- 
hol are gone. In all cases the drying should be completed the day 
it is begun. 

"Prove purity of the extracted fat by solution in petroleum 
ether. If a residue remains, filter the ether into another tared 
flask and wash flask, filter and funnel with petroleum ether. 
Evaporate, dry and weigh as before. If the work has been prop- 
erly done, neither a third extraction nor purification of the fat is 
necessary. A blank determination should be made unless the re- 
agents are known to be free from residue. This blank is small, 
being perhaps about 0.01 and 0.02% with proper reagents. 

"The petroleum ether and ethyl ether used should be distilled 
to insure their purity. Petroleum ether employed should boil 
below 65° C." 



MojoNNiUR Fat Te;st 43 

Biesterfeld and Evensou in 1917^'' reported results obtained by 
the Rose-Gottlieb method upon condensed milk and milk pow- 
ders. By following the extraction in the usual alkaline medium, 
with an additional extraction in an acid medium, they recovered 
a trace of fat which they believed could not be recovered by the 
alkaline extraction alone. Their suggestion has not come into 
general use partly on account of the extra time required, and 
partly on account of the small factor of safety which the trace of 
remaining fat may provide. 

The Mojonnier modifications of the Rose-Gottlieb method are 
based both upon the process and apparatus patents applied for 
or granted to J. J. Mojonnier. The patents issued to date are 
as follows: 

Process patent April 3, 1917, Sept. 27, 1921 ; Apparatus patents 
Feb. 5, 1918, April 9, 1918, June 11, 1918, and Aug. 5, 1919. Num- 
erous claims upon additional patents not yet issued have been 
allowed. 

The improvements have made it possible to shorten the 
time greatly and also to increase largely the accuracy of the 
test. Some of the earlier methods of testing dairy products were 
rapid, but the results were inaccurate. The Rose-Gottlieb method 
as originally applied, and to a considerable extent several of 
the earlier methods were accurate but slow. Too much time was 
required to make a test to make the methods practicable for fac- 
tory control work. The improvements invented by Mojonnier 
combine in one apparatus a means for obtaining both accuracy 
and speed. These two considerations are equally valuable when 
dealing with dairy products that are at once both valuable and 
perishable. Fig. 12 shows graphically the saving in time by 
the Mojonnier modifications, as compared with the Rose-Gottlieb 
method. 

Butter Fat Test 

■■■■ Mojonnier Test — 30 minutes 



Official Test — 3 hours. ..Six times as long. 
Fig*. 12. Savingr in Time Upon Fat Test Mojonnier Method. 



44 Fat and Total Souds Tests 

THE MOJONNIER MILK TESTER. 

This is the name applied to the apparatus devised by Mojon- 
nier for applying his modifications of the Rose-Gottlieb method. 
A novel feature of the Mojonnier Tester is the fact that it com- 
bines in one equipment, methods and apparatus for making both 
fat and moisture (or total solids) tests. This dual feature is not 
found in any other apparatus upon the market. Inasmuch as the 
above two tests are the most important tests required in apprais- 
ing the value of dairy products, the ability to make rapidly both 
tests simultaneously upon the same product with the certainty of 
getting accurate results, becomes at once obvious. The develop- 
ment of the total solids test will be treated in other paragraphs of 
this chapter. 

REAGENTS TO BE USED IN THE MOJONNIER MILK TEST AND 
THEIR FUNCTIONS. 

The reagents used in making fat tests upon the Mojonnier 
Tester are as follows : 

(1). Distilled water. This should be free from oil, or any 
kind of mineral residue, and as nearly chemically pure as pos- 
sible. It should be stored in glass, enameled steel, or tinned cop- 
per containers. 

(2). Ammonia. Commercial, chemically pure, testing about 
26° Baume, or .8974 specific gravity at 60'' F. and containing 
about 29.40 per cent ammonia gas (NH3). 

(3). Alcohol. 95 per cent, 190° proof, .8164 specific gravity 
at 60° F. best quality grain or ethyl alcohol. Should not leave 
any residue upon evaporation. 

(4). Ethyl Ether. Best commercial quality. To contain not 
more than 4 per cent of water. Specific gravity .713 to .716 at 
25° C. Boiling point about 35° C. To leave no residue upon 
evaporation. If there is any doubt as to its purity, it should be 
re-distilled before using. It should be stored in a cool place. It 
is both inflammable and explosive, and care must be exercised in 
its handling. It should be stored in glass, glass enameled, or 
tinned steel containers. 

(5). Petroleum Ether. Best commercial quality. Specific 
gravity .638 to .660 at 25^ C. Boiling point not over 120 to 140° F. 



Reagents 45 

Should distil at not over 140° F., and leave no residue upon 
evaporation. If there is any doubt as to its purity, it should be 
re-distilled before using. It should be handled with the same 
care and in the same manner as ethyl ether. 

RUNNING BLANKS UPON REAGENTS. 

Too much emphasis cannot be placed upon using reagents of 
the proper purity. Blank determinations using water instead of 
milk should be made frequently, as errors which can be avoided 
may creep into the work. 

THE FUNCTION OF THE VARIOUS REAGENTS. 

Water. Distilled water is added to concentrated milk prod- 
ucts in the flask in order to bring the substances to the fluid con- 
dition of whole milk, and to provide a liquid to carry the solids 
not fat in solution when they are dissolved by the other reagents. 
Sometimes it is also necessary to add a little water after centrifug- 
ing the second extraction in order to bring the dividing line be- 
tween the ether fat solution and the solids not fat solution up to 
the desired point which permits all of the ether fat solution to be 
poured from the flask without removing any of the other sub- 
stances. 

Ammonia. The ammonia is added to dissolve the casein which 
is not in true solution in milk, but is present in the form of minute 
gelatinous particles evenly distributed throughout the mass. It 
also neutralizes the acidity of the product. This reduces the 
viscosity of the mixture, and permits the solvent which is added 
later to more readily dissolve the fat. The ammonia would also 
probably tend to destroy colloidal phosphorous compounds, if any 
are present, and still further reduce the viscosity. 

Alcohol. The alcohol assists in preventing the formation of 
the characteristic gelatinous mixture which occurs when ether is 
vigorously shaken with milk. It thus enables the solvent to 
come in contact with the fat globules during the shaking opera- 
tion, and also allows the ether fat solution to collect in a layer 
when all of the fat has been dissolved. 

Ethyl Ether. Ethyl ether dissolves the fat and holds it in its 
own solution. It also dissolves a small amount of the milk sugar 



46 Fat and Total Solids Tests 

and other solids not fat which, if not corrected, would cause er- 
roneous results. 

Petroleum Ether. Petroleum ether is also a good fat solvent, 
but in this test it assists especially in throwing out from the ethyl 
ether-fat solution the last traces of water. The water holds milk 
solids not fat in solution and if any of the water is carried over 
with the ether-fat solution the other solids would be present with 
the fat when it is finally dried and weighed, thus causing results 
that would be too high. It throws out of the ethyl ether solution 
any solids not fat that may have been dissolved therein. 

Phenolphthalein is sometimes added to the extent of a drop 
or two before pouring off the ether solution. This makes a sharp 
dividing line between the ether solution and the non-fatty residue, 
but this practice is not recommended, owing to the slight solubility 
of phenolphthalein in ether which causes too high results. 

EFFECT OF USING EITHER MORE OR LESS THAN THE 
STANDARD AMOUNT OF THE VARIOUS REAGENTS. 

Table 5 gives the results obtained by varying in turn the 
various reagents used in making the fat tests. The object being 
to ascertain the effect of such variations, and the limits allowable 
without affecting the accuracy of the tests. Five sets of experi- 
ments were made, varying in turn each of the five reagents. In 
one case the regular quantity of all reagents was used. In the 
second case less than the regular amount of any one reagent was 
used, leaving the others constant. In the third case more than 
the regular amount was used, leaving the others constant. 



Reagents 



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Fat and Total Souds Tests 



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Comparative; Tests 49 

A study of the results given in the preceding table proves the 
importance of using the various reagents in the right proportion, 
one to the other, and in the proportions that have been found by 
experience to give the correct results upon the various dairy prod- 
ucts. The quantity of both water and alcohol used have the 
largest influence upon the accuracy of the results. Using too lit- 
tle water causes a gelatinous precipitate when the ethyl ether is 
added, and in turn this causes low results. Using too much water 
raises the dividing line in the extraction flask, and makes it im- 
possible to pour off completelj^ the ether solution containing the 
fat, from the remainder of the reagents. Using too little alco- 
hol causes particularly a heavy jelly upon adding ethyl ether, and 
in turn causes results that are greatly in error. This emphasizes 
the importance of using only the best quality of ethyl alcohol, 
conforming to the specifications given. Using too much alcohol 
frequently causes too high results, due to raising the dividing 
line too much. Using too little of either ethyl or petroleum ethers 
causes too low results on account of the extraction of the fat be- 
ing incomplete, while using too much causes a waste of reagents 
without increasing the accuracy of the test. Variation in the 
quantity of ammonia used causes less disturbance than varia- 
tion in the quantity of the other reagents. 

RESULTS OF COMPARATIVE FAT TESTS RY MOJONNIER 
METHOD AND OTHER METHODS. 

Comparison of results by Mojonnier and Babcock methods 
upon whole milk. 

A careful experiment was made to determine the relative effi- 
ciency of the Babcock method as applied to fresh milk with the 
Mojonnier method. The tests using the Babcock method were 
made in two different Chicago laboratories. The tests using the 
Mojonnier method were made by F. M. Bundy. The results of 
the experiments are given in Fig. 13, next page. 

The horizontal line, which may be called the standard line, 
represents the values obtained using the Mojonnier method. The 
spots and stars represent the amount overread or underread by 
the Babcock method. 



50 Fat and Total Solids Tests 



.30 


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* LABORATORY N0.1 • 

LABORATORY NO 9 • 
UNOERPAIO 



Tig. 13. Results by Mojonnier and Babcock Methods Upon Whole Milk. 

Only the difference between the two methods is shown. All 
values above the standard line show overreading. All under the 
standard line show underreading. The stars give the values ob- 
tained by one laboratory, and the round spots those obtained 
by the second laboratory upon the same sample. The amounts 
that would have been overpaid or underpaid had the tests been 
obtained in a plant that buys its milk upon the butter fat basis 
are given both in per cents and in cents per 100 pounds, at the 
left of the table. Each one-tenth per cent is assumed to have a 
value of four cents. The differences, if any upon the same sam- 
ple as reported by the two respective laboratories, are repre- 
sented by the vertical bands connecting the stars and the round 
spots. 

The results of the experiments show plainly the wide varia- 
tion in tests obtained by the same operator, and also between 
two different operators. Out of a total of 52 samples tested, 
laboratory No. 1 reported 30 samples that tested more than .05% 
either over or under the standard line, and laboratory No. 2 upon 
the same number of tests, reported 27 samples that tested like- 
wise. Out of 104 tests, irrespective of the operator, 51.9% of the 
tests were overread and 43.3% were underread. 

A COMPARISON OF THE FAT PERCENTAGES ORTAINED IN 

SEVERAL MILK PRODUCTS BY DIFFERENT 

METHODS OF TESTING. 

Under the direction of one of the authors^" in the dairy test- 
ing laboratory at Cornell University determinations were made 



Comparative Tests 



51 



by various methods of the fat content of different dairy products. 
The results are given in the tables immediately following. 

TABLE 6. 
Fat Content of Whole Milk as Found by Three Methods; upon 14 Different 

Samples. 



Sample 
Number. 


Mojon- 
nier, 


Adams. 


Babcock. 


Sample 
Number. 


Mojon- 
nier, 


Adams. 


Babcock. 


1 


4.22 


4.17 


4.30 


8 


5.16 


5.11 


5.00 


2 


3.67 


3.62 


3.60 


9 


4.40 


4.44 


4.30 


3 


3.98 


3.91 


4.10 


10 


3.40 


3.34 


3.40 


4 


4.76 


4.77 


4.80 


11 


4.23 


4.25 


4.30 


5 


3.64 


3.61 


3.60 


13 


3.32 


3.30 


3.40 


6 


4.71 


4.62 


4.80 


13 


4.78 


4.71 


4.80 


7 


3.87 


3.86 


3.90 


14 


4.85 


4.82 


5.00 



The results in the above table shov7 a close agreement between 
the Mojonnier and the Adams methods, when applied to fresh 
milk. There is a considerable disagreement in results between 
the Babcock and the other two methods. The difference is not 
constant in one direction, as in other comparative tests reported 
in this chapter. 

TABLE 7. 

Fat Content One Sample Cream Tested Seven Times by Two Methods, and 

One Sample Evaporated Milk Tested Eight Times by Three Methods. 



Cream, 


Evaporated Milk. 


Mojonnier 
method. 
Per cent. 


Babcock 
method. 
Per cent. 


Mojonnier 
method. 
Per cent. 


Adams 
method. 
Per cent. 


Babcock 
method. 
Per cent. 


36.68 


37.00 


8.07 


7.92 


7.90 


36.75 


37.50 


8.05 


7.97 


8.00 


36.68 


37.50 


8.05 


8.08 


7.90 


36.69 


37.25 


8.11 


7.93 


8.20 


36.70 


36.50 


8.08 


7.96 


8.30 


36.74 


37.00 


8.07 


8.06 


8.00 


36.70 


36.50 


8.08 


8.03 


8.40 







8.07 


8.00 


8.20 



The above results show the close agreement by the Mojonnier 
method upon both products, and the considerable disagreement 
in results by other methods, both within themselves, and by 
comparison with the Mojonnier method. 



52 Fat and Total Solids Tests 

TABLE 8. 

Fat Content of Skim-Milk as Found by the Mojonnier and the Babcock 

Methods. Tests Made by Prof. T. J. Mclnerney, Cornell Univ. 



Sample. 


Mojonnier 

method. 
Duplicate. 


Babcock 

test. 

Duplicate. 


Difference. 
Duplicate. 


1 


.10 — .10 


.05 — .05 


.05 — .05 


3 


.10 — .10 


.06 — .06 


.04 — .04 


3 


.11 — .11 


.03 — .03 


.08 — .08 


4 


.07 — .09 


.05 — .05 


.02 — .04 


5 


.29 — .30 


.26 — .26 


.03 — .04 


6 


.07 — .07 


.01 — .02 


.06 — .05 


7 


.074— .074 


.04 — .04 


.034— .034 


8 


.08 — .08 


.03 — .04 


.05 — .04 


9 


.24 — .27 


.14 — .14 


.10 — .13 


Average 


.126 — .132 


.074— .076 


.051— .056 



The above results prove that the Babcock method gives too 
low results when applied to skim-milk. The shortage in this 
experiment was found to range from .02 to .13%, or upon the 
average about .06%. 

COMPARISON OF RESULTS UPON SAME PRODUCT BY 
DIFFERENT OPERATORS, USING MOJONNIER METHOD. 

One sample of sweetened condensed milk was tested by six 
different operators using the Mojonnier method. The results 
obtained are given in the following table. 

TABLE 9. 

Fat Content Same Sample Sweetened Condensed Milk by Mojonnier Method, 

as Found by Six Different Operators, Compared with Results 

by Official Method.'" 



Operator No. 


Where tests were made. 


Per cent fat found. 


1 
2 
3 


Pecatonica, 111. 

Grayslake, 111 

Burlington, Wis. 


8.38 
8.44 
8.38 


4 


Burlington, Wis. 


8.38 


5 
6 


Valders, Wis 

Valders, Wis. 

Burlington, Wis 


8.37 
8.36 
8.36" 



The above results indicate the close agreement possible to 
obtain between different operators, being one of the best possible 
proofs of the accuracy of the method. 



Comparative; Tests 



53 



TABLE 10. 
Fat Content of Buttermilk by the Mojonnier and Babcock Methods 



Mojonnier Method. 


Babcock Method, | 

Regular Procedure. 

17.6 cc. buttermilk. 

17.6 cc. acid, 16" disk. 

Centrifuged atlOOOR.P.M. 

for 5, 2 and 1 mins. 


Babcock Method, 

Modified Procedure. 

17.6 cc. buttermilk. 

23.0 cc. acid, 16" disk. 

Centrifuged atlSOGR.P.M. 

for 10, 2 and 1 mins. 




Pei- cent 


fat. 


Per cent fat. 


Per cent fat. 




Original. 


Duplicate. 


Original. 


Duplicate. 


Original. 
.44 


Duplicate. 


1 


.528 


.523 




.46 


3 


.693 


.710 


.12 


.12 


.41 


.46 


3 


.661 


.667 


.16 


.14 


.37 


.31 


4 


.333 


.332 


.04 


.04 


.06 


.07 


5 


.356 


.350 


.05 


.04 


.09 


.07 


6 


.299 


.295 






.18 


.18 


7 


.328 


.320 


.05 


.05 


.21 


.22 


8 


.325 


.323 


.03 


.03 


.09 


.13 


9 


.431 


.390 


.08 


.08 


.20 


.20 


10 


.480 


.440 


.17 


.17 


.27 


.27 


11 


.597 


.586 


.26 


.25 


.34 


.37 


12 


.431 


.449 


.07 


.07 


.30 


.30 


13 


.432 


.434 


.12 


.12 


.20 


.20 


14 


.472 


.475 


.11 


.11 


.25 


.25 


15 


.447 


.451 


.10 


.10 


.25 


.25 


16 


.386 


.382 


.05 


.06 


.18 


.20 


17 


.649 


.646 


.27 


.27 







The above results indicate that the present method of apply- 
ing the Babcock test to the determination of fat in buttermilk 
is useless, as it is misleading, and it may lead to considerable 
loss. 



COMPARISON OF RESULTS BY MOJONNIER AND BABCOCK 
METHODS UPON ICE CREAM MIX. 

A number of compartive tests upon the different qualities of 
ice cream mix are given in the following table.-- 



54 



F'at and Total Souds Tests 



TABLE 11. 

Compaiison of Results by Mojonnier and Babcock Methods Upon Ice 

Cream Mix. 



Wholesale grade. All ingredients in 
mix. Ready for freezing. 


Philadelphia grade. All ingredients 
in mix. Ready for freezing. 


Per cent fat. 


Per cent fat. 








Over 


Under- 






Over- 


Under- 


Sam- 
ple 


Mojon- 
nier 


Bab- 
cock 


read- 
ing 


read- 
ing 


Sam- 
ple 
No. 


Mojon- 
nier 


read- 
Bab- ing 


read- 
ing 


No. 


By Babcock 
method. 


By Babcock 
method. 


1 


9.85 


8.50 




1.35 


22 


14.39 


14.00 . . 




.39 


2 


10.62 


8.60 




2.02 


23 


14.89 


15.00 .11 




3 


10.09 


8.40 




1.69 


24 


16.70 


15.50 . . 




1.25 


4 


9.61 


8.35 




1.26 


25 


14.64 


14.40 




.24 


. 5 


9.65 


8.40 




1.25 


26 


15.15 


15.40 .25 




6 


10.36 


9.20 




1.16 


27 


14.77 


14.80 .03 




7 


9.55 


8.40 




1.15 


28 


15.81 


15.40 . . 




.41 


8 


10.00 

10.18 

9.72 

9.61 


9.60 
9.60 
9.60 
9.00 




.40 
.58 
.12 
.61 


29 


15.33 


15.00 . . 




.33 


9 
10 


Speci 


al mi.x. No cane sugar added. 


11 


30 


11.09 


8.00 . 




3.09 


12 


9.83 


9.60 




.23 


31 


11.80 


10.00 . 




1.80 


13 


10.12 


9.20 




.92 


32 


12.58 


9.80 . 




2.78 


14 


10.35 


8.80 




1.55 


33 


11.92 


9.60 . 




2.32 


15 


10.03 


9.00 




1.03 


34 


11.82 


9.20 




2.62 


16 


10.02 


8.80 




1.22 


35 


11.60 


8.50 . 




3.10 


17 


10.43 


9.60 




.83 


36 


11.20 


8.65 




2.55 


18 


10.36 


9.20 




1.16 


37 


12.04 


9.10 . 




2.94 


19 


10.72 


10.40 




.32 


38 


11.78 


9.30 . 




2.48 


20 


9.44 


9.60 


.16 


. . . 












21 


10.09 


9.80 




.29 













In the above mixes the milk S, N. F. was as follows : 

Philadelphia grade 6.50% milk S. N. F. 
Wholesale grade 10.00% milk S. N. F. 
Special mix 18.00% milk S. N. F. 

Inasmuch as the mix containing the lowest amount of milk 
S. N. F. shows the closest agreement, and that containing the 
most, the greatest disagreement in results by the two methods, 



Accuracy of Tests 55 

W. 0. Frohring," concludes that this factor largely controls the 
difference. Other factors causing errors by the Babcock method 
enter into the testing of ice cream mix, as well as in the case of 
other dairy products. The results given in the table indicate 
the possibilities for serious errors when the Babcock method is 
used to test ice cream mix. 

The results reported by the Babcock method included only 
those in which the fat column was entirely clear. Nine grams of 
the ice cream mix were placed in eight per cent milk bottles. To 
this was added 9 c. c. of acetic acid, and the usual amount of 
sulphuric acid. All readings were made from a water bath at 
140° F. 

PROOFS OF ACCURACY OF FAT DETERMINATIONS MADE BY 
THE MOJONNIER METHOD. 

In a careful experiment-^ the fat obtained from a large num- 
ber of milk fat extractions on the Mojonnier Tester was itself 
tested for purity by the Mojonnier method. The fat was weighed 
into the extraction flask, 10 c. c. of water added and the deter- 
mination completed in the usual way. The results were as 
follows : 

Weight of fat in the sample taken 4004 

Weight of fat recovered 4003 

Per cent of fat in the fat extracted from 

milk products 99.98 

Per cent of moisture in the fat extracted 
from milk products 0.02 

These results prove that the substance extracted from milk 
products by the Mojonnier method is practicall}^ chemically pure 
milk fat. 

In another experiment an accurately weighed amount of pure 
fat was placed in an extraction flask and extracted according to 
the procedure described above. With two extractions 99.90 per 
cent of the fat was recovered. With three extractions 99.97 
per cent was recovered. When pure fat was added to skim-milk, 
in which the fat had been previously determined for the purpose 
of making the necessary corrections, the total recovery of the 
pure fat amounted to 99.96 per cent with two extractions. 



56 Fat and Total Solids Tests 

These results show that pure fat under the conditions given 
can be practically completely recovered when the determina- 
tion is made by the Mojonnier method. 

For the purpose of comparison, in another experiment, two 
large samples of the product recovered from the fat column in 
Babcock test bottles were tested for fat, moisture, and total 
solids with the results given in Table 12. 

TABLE 12. 
Composition of Fat Column in Babcock Test Bottles 



Sample. 


Per cent of 
moisture. 


Per cent of 
Solids not fat. 


Per cent 
of fat. 


No. 1'* 

No. 2^= 


3.01 

.85 


6.29 
3.99 


90.70 
95.16 



These results show that the fat column in the Babcock test is 
not composed of pure fat. The amount of substances not fat 
present are probably offset to some extent by the fat not col- 
lected in the fat column, but no doubt variations in the amount 
of these substances in the fat column are responsible for some 
of the inaccuracies of the test. 

(B) TOTAL SOLIDS AND MOISTURE TESTS. 

The total solids test of many dairy products ranks closely in 
importance with the fat test. Among the principal reasons being 
that the percentage of total solids in pure milk varies between 
quite wide limits ; the minimum percentages for total solids have 
been fixed in many cases by legislative enactments, and by muni- 
cipal and state regulations, and in the manufacture of concen- 
trated milk products. The percentage of total solids affects both 
the process and the quality of the product and the cost thereof. 

As in the case of butter fat, a large amount of work has been 
done in the past in devising satisfactory methods for estimating 
total solids in milk and its products. The efforts have been 
directed principally in two directions, namely (1) by formulas 
based upon the butter fat test and the specific gravity, and (2) 
by various modifications of gravimetric methods, 

Babcock,^^ Richmond" and Fleischman,^^ all published formulas 
for calculating total solids in dairy products. These formulas 



SOUDS FoRMUIvAS 57 

are all based upon knowing the specific gravity of the milk, and 
the percentage of fat present, so that these determinations have 
to be made before the percentage of total solids can be calculated. 
If the method is used in practical work, the Quevenne lac- 
tometer reading is taken, and this reading is used in the formula. 
The fat is determined by the Babcock or similar method. "Work- 
ing in this way the calculations can be depended upon to give 
only a rough approximation of the true percentage of total solids 
present, particularly in the case of condensed milk products. 
The Babcock formula is favored in this country over other 
formulas. It is as follows: 

Total solids =-^-f 1.2 xF 

L = Quevenne lactometer reading 
F = Per cent of fat 
Problem : The Quevenne lactometer reading of a milk sample 
is 31 and the per cent of fat is 3.60. 

Q1 

Total solids =:^ + 1.2 x 3.6 = 12.07 

4 ' 

Another formula that gives results as dependable as the above 
especially when used on rich milk is the following : 

Solids not fat == ^ — ■ 

4 

Problem : The Quevenne lactometer reading of a milk sample 

is 32 and the per cent of fat is 3.80. 

32-t- 3 80 * 

Solids not fat — — = 8.95%, 

8.95%, + 3.80 = 12.75, % of total solids 

This subject is discussed at length by numerous authorities to 
which the reader is referred for further information. 

In the gravimetric methods the underlying principle in all 
cases is the same, but they differ from one another in many par- 
ticulars. In all cases a weighed quantity of milk is dried to 
constant weight at about the temperature of boiling water, either 
with or without the use of any absorbent materials. Among the 
best known of the gravimetric methods are the Babcock asbestos 
method, the method of the Society of Public Analysts of England, 
the Adams paper coil method and Mojonnier method. 



SS F'at and Totai, Solids I'^esTS 

Bigelow and Fitzgerald-" in their able research made a 
thorough investigation of methods for determining total solids 
in evaporated milk. They found "that the addition of sand to 
milk in drying constitutes a danger rather than a safeguard, 
and needlessly complicates the method." 

The gravimetric method recommended by them for deter- 
mining total solids in evaporated milk was as follows : 

"Weigh two grams of sample into a three-inch lead bottle cap ; 
add about 5 c. c. of water to dissolve the milk and distribute it 
over the bottom of the dish; heat in the water jacketed oven 
under atmospheric pressure until the sample is evaporated to 
apparent dryness. Continue heating for four hours and weigh. 
Eeturn to the oven and heat again for two hours and weigh. If 
the two weights show a loss of more than 0.05 per cent, the 
heating is continued, with weighings at two hour intervals until 
the last two weighings do not differ by more than 0.05 per cent." 

They made a comparative study of results obtained by the 
above gravimetric method, and by formula based upon the but- 
ter fat test and the specific gravity of the sample. The formula 
recommended by them to be used with both raw and evaporated 
milk was as follows : 

Per cent total solids = 1.2 x fat + (specific gravity — 1.000) 
0.25. 

They found "that with sterilized evaporated milk more ac- 
curate results were obtained on the original samples than after 
dilution. Before sterilization the product is of course, more 
fluid and the specific gravity can be determined more readily, 
and the results are somewhat more accurate than in the processed 
milk. Even in that case, however, the method of calculation 
from the specific gravity is not as accurate as the determination 
by drying, and the latter is strongly recommended." 

The results reported are given in Table 13. 

J. J. Mojonnier introduced the method now known as the 
Mojonnier method in 1915. The principles underlying this 
method are covered by process patents dated April 3, 1917. It 
differs in several particulars from all other methods previously 
employed. 



MojoNNiER Solids Test 



TABLE 13. 



59 



Total Solids Found by Formula and by Gravimetric Method. Bigelow and 

Fitzgerald. 





Per cent total solids. 


Sample 

No. 


Calculated from specific gravity. 


Specific 

gravity 

bottle, 

undiluted. 


Specific 

gravity 

bottle, 

rliluted 1—1. 


"Westphal 

balance, 

diluted 1—1. 


Specific 

gravity 

spindle, 

undiluted. 


By 

drying. 


802 
807 
824 
834 
836 
837 
840 


26.64 
26.46 
26.87 
26.76 

24.77 
26.88 
28.70 


26.29 

26.28 

26.27 
24.49 
26.60 
28.32 


26.44 
26.28 
26.84 
26.47 
24.89 
26.84 
28.68 


26.83 

26.83 
26.56 
24.71 
27.29 
28.89 


26.68 
26.54 
26.81 
26.50 
25.05 
27.13 
28.59 



The patented apparatus designed to carry out the method is 
all embodied in the Mojonnier Tester, already described. The 
two main advantages of the Mojonnier method are the great sav- 
ing in time possible to effect, and the increased accuracy of the re- 
sults obtained. The saving in time over the official method is 
illustrated by Fig. 14. 



Total Solids Test 

Mojonnier Test — 25 minutes. 



Long- Drying Test — 7 hours. Seventeen times as long. 
Fig*. 14. Saving- in Time ITpon Total Solids Test. 

PROOF OF ACCURACY OF THE MOJONNIER TOTAL SOLIDS TEST. 

A series of ten total solids determinations upon the same sam- 
ple of evaporated milk were made by J. J. Mojonnier upon April 
7, 1915, with the following results: 25.95, 25.91, 25.95, 25.97, 
25.93, 25.91, 25.97, 25.92, 25.93 and 25.99. 

These results show marked agreement in the entire series. 

Through the courtesy of the National Dairy Co., Toledo, Ohio, 
we report the results given in Table 14, being the tests obtained 



60 



Fat and Total Souds Tests 



upon samples of milk from the same batches by their operators 
of the Mojonnier Tester, and by the operator in the central 
laboratory at Chicago, also using the Mojonnier Tester. 



TABLE 14. 
Total Solids Test Upon Evaporated Milk by Two Operators. 



Where tests were made. 


Sample 
No. 25 


Sample 
No. 36 


Sample 
No. 59 


Sample 
No. 82 


N'ational Dairy Co., Morenci, Mich. . . . 

Mojonnier Bros. Co., Chicago, 111.; 

Miss Lucy Klein 


26.66 
26.57 


26.19 

26.24 


26.30 
26.29 


26.41 
26.40 







The ability of different operators to obtain practically dupli- 
cate results upon the same samples of evaporated milk is one of 
the best proofs of the accuracy of the method. 

We are also indebted to the Wisconsin Condensed Milk Co. for 
comparative tests upon sweetened condensed milk samples all 
from the same batch, tested by different operators using the 
Mojonnier Tester, in comparison with test by the official method. 
The results are reported in Table 15. 



TABLE 15. 
Total Solids Tests Upon Sweetened Condensed Milk by Several Operators. 



Operator 
No. 


Where tests were made. 


Per cent total solids 
found sweetened con- 
densed milk. 


1 


Pecatonica, 111 


73.27 


2 


Grayslake, 111 


73.41 


3 


Burlington, Wis 


73.41 


4 


Burlington, Wis 


73.50 


5 


Valders, Wis 


73.50 


6 


Valders, Wis 


73.31 


Mr. Titus' 
official test. 


Burlington, Wis 


73.53 



Considering that sweetened condensed milk is probably the 
most difficult dairy product to test successfully for total solids, 
the results reported show a close agreement with those obtained 
by the long official methods, 



Rei^ErEnces 61 

references. 

1 Rose, Bruno: Analysis of Milk: Fat Determinations. Zeitschrift fur 
Angewandte Chemie. Abst. in Jour. Chem. Soci., Vol. 54, p. 1135, 1888. 

^ Schreib, H.: Determination of Fat in Milk. Zeit. Angewandte Chem., 
Vol. 1, p. 135, 1888. Abst. in Jour. Chem. Soci., Vol. 54, p. 1135, 1888. 

'Gottlieb. E.: Estimation of Fat in Milk. Milkerei Zeitung, 1892, II. 
Landw. Versuchs.-Stat., Vol. 40, p. 1-27. Abstract in Jour. Chem. Soci., Vol. 
62, p. 549-550, 1893. Patrick, U. S. Dept. Agric, Bur. of Chem., Circ. 66; A. O. 
A. C. Methods, 

* Lang: Pharm-Zeitg., 38, 219. Chem. Centr., 1. 960, 1893. 

sWeibull: Milk Ztg.. Vol. 27, p. 406, 1898. Cheni. Ztg., No. 63, 1898. 

«Kuhn: Milk Ztg., Vol. 27, p. 772, 1898. 

■^ Popp, M.: Zeitschrift fur Untersuchung der Nahrungs- und Genussmit.. 
Vol. 7, p. 772, 1. 

s Popp, M.: Milch.-Ztg., 1904, No. 20. 

» Rohrig: Amir. Zeit. Nahr. Genussm., A^ol. 9, p. 531-538, 1905. 

I'Thomsen: Th. Sv. Landw. Versuchsstat., Vol. 62, p. 387-399, 1905. 

"Burr, A.: Milchw. Zentr., 1, 248-250. Abstract Jour. Chem. Soc, 88. 2, 
559-560, 1905. 

'2 Gordon. P.: Milchw. Zentr., 2, 224-227, 1906. Jour. Chem. Soci., 90, 2, 
501, 502, 1906. 

'*Barthel. Dr. Chr.: "Milk and Dairy Products." Translated by Goodwin, 
"W., Ph. D., MacMillan & Co., N. Y. p. 52-55, 1910. 

^* Kropat, K. : Arch, der Pharmacie, Vol. 252, p. 76-82, 1914. Jour. Soci., 
106, 2, p. 591, 1914. 

's Richmond. H. D.: Dairy Chemistry. Second Ed. Revised, p. 118-119, 
1914. 

i« Meniere, G. J.: Pharm. et Chim. (7) 9, p. 489-493, 559-563, 1914. Jour. 
Chem. Soc, 106, 2, p. 590, 1914. 

'^Balton, E. R., and Revis, C: Fatty Foods, Their Practical Examination. 
London, 19, p. 347-349. 

'*Bigelow, W. D., and Fitzgerald: The Examination of Evaporated Milk. 
Bull. No. 5, Jan., 1915. Research Lab. Nat. Canners Assn., Washington, D. C 

i» Biesterfeld & Evenson: Jour. Ind. & Eng. Chem., 1917. 

*'» Courtesy Wisconsin Condensed Milk Co. 

21 Test made by Mr. Titu,s, Burlington, Wis., using official Rose-Gottlieb 
Method. 

22 Courtesy Telling-Belle Vernon Co., Cleveland, Ohio. Results reported 
by W. O. Frohring, Director of liaboratories. 

23 Miss Lucy Klein: Mojonnier Bros. Co., Chicago, 111. 

2* Sample from Dairy Testing Laboratory. N. T. State College of Agricul- 
ture. Analyst, Miss l./ucy Klein, Chicago, 111. 

-s Analyst, F. M. Bundy, Chicago, 111. 

2«Babcock: Univ. of Wis. Agr. Exp. Sta., 1895, 12th, Rep't., p. 120. 

2'' Richmond: "Dairy Chemistry," 1914, p. 68. 

28 Fleischmann: Lehrbuch der Milchwirtschaft. 

2» Bigelow & Fitzgerald: The Examination of Evaporated Milk, 1915. Bull, 
No. 5. Research Lab., Nat. Canners Assn., Washington, D. C. 

»o H. C. Troy. 



CHAPTER IV 
ASSEMBLING THE MOJONNIER MILK TESTER 

The Mojonnier Milk Tester is a machine invented especially 
for the purpose of quickly determining, with the greatest chem- 
ical accuracy, the percentages of fat and solids in all dairy 
products. 

The Mojonnier Milk Tester is supplied in three models. Model 
A is electrically operated with rheostatic heat control throughout. 
Model D is electrically operated, with rheostatic heat control upon 
the two outside hot plates, and with thermostatic heat control 
upon the two ovens. This insures uniform temperature upon both 
ovens, regardless of any fluctuations in the voltage. Model G is 
steam operated. The three models are illustrated under Figures 
15, 16 and 17, respectively. 




Viir. 15. Model A Mojonnier Milk Tester. ElectricaUy operated. Rheostatic 

heat control. 

[ 62 ] 



MoDKlvS 



63 




Figr. 16 Model D Mojonnier Milk Tester. Electrically operated. Thermo- 
static heat control upon the two ovens. 




Tig. 17. Model G Mojonnier Milk Tester. Steam operated throughout. 



64 



ASSEMBUNG MOJONNIER MlI,K TesTER 



SETTING UP THE MOJONNIER MILK TESTER. 

In assembling and locating the Mojonnier Milk Tester in the 
plant, follow instructions closely. The illustration Fig. 18 will 
assist in properly setting up the Tester. The tester must be 
placed in a room with a good solid floor, in order to prevent vibra- 
tion of the chemical balance. Choose a corner space preferably, 
or a straight wall. The air in the room should be fairly dry and 
the temperature between day and night should not vary widely. 



30 31 25 



II 7 10 3 13 6 4 




1 r 
16 29 14 15 19 18 24' 

The Mojonnier Milk Tester. Model A. 

(1.) All tests for fat are made upon this side, which is called 
the fat side. 

(2.) All tests for total solids are made upon this side, which 
is called the solids side. 

(3.) Butter fat extraction flasks in centrifuge baskets. 

(4.) Eight 3|" diameter aluminum dishes for fat tests. These 
are the larger " dishes furnished with the Tester. The one tall 
counterpoise counterbalances each dish. Fat dishes have no 
covers. 



Parts 65 

(5.) Eight 3" aluminum dishes for solids tests. These are 
the smaller dishes furnished with the Tester. The one short 
counterpoise counterbalances each dish. Cover prevents absorp- 
tion of moisture from the air during weighing. Counterpoise 
balances both dish and cover. 

(6.) Fat vacuum oven. The temperature in this oven is main- 
tained at 135 deg. C. Thermometer (10) extends into vacuum 
oven and sets in the mercury well, which in turn rests upon the 
hot plate. About once a month the mercury well should, be re- 
filled with mercury. Be careful to see that the well always forms 
good contact with hot plate. Regulate temperature by rheo- 
stat (15). 

(7.) Cooling chamber. Water at room temperature from the 
tank in bottom part of the fat side is pumped by means of cir- 
culating pump in power unit (20) through the flat hollow sheet 
brass plate inside the cooling chambers, and from there into pipe 
back of the Tester, then back into tank. Operator must watch 
outlet on cooling chamber, and see that water is flowing at all 
times while the motor is running. If water is not running, you 
may know that the water in the storage tank- is low, or that the 
water circulating pump is out of repair. Keep the tank filled at 
all times. In winter to prevent freezing, put one gallon of de- 
natured alcohol into the tank. Also when filling tank, put in one- 
half gallon soluble oil furnished with the Tester, This will assist 
greatly in keeping the circulating pump in repair. 

(8.) Solids oven. Maintained at 100*^ C. Regulate tem- 
perature by means of the rheostat (16). Follow instructions in 
(6) above closely for method of placing thermometer. Keep joints 
at door clean, and grease the sliding surfaces with vaseline. This 
prevents rusting of the ground surfaces, and insures a more per- 
fect vacuum, 

(9 and 10.) These are the 250° C. thermometers furnished for 
the solids and fat ovens respectively. Two sizes of gum tubing 
are furnished, for fastening the thermometers to the ovens. No 
other quality of tubing should be used, and if necessary, the tub- 
ing should be wired to the thermometer and to the oven connec- 
tion. 



(^ Assembling Mojonnier Milk Tester 

(11.) The vacuum gauge is on the main suction line from 
the vacuum pump. This registers the vacuum upon either oven, 
or upon both ovens simultaneously. 

(12.) Outside solids plate. Maintained at 180° C. The ther- 
mometer can be placed in the nickel plated mercury well that 
rests directly upon the heating plate. See that this side is level, 
so that the solids may dry evenly upon the bottom of the dish. 

(13.) Outside fat plate. Maintained at 135° C. During the 
evaporation of ether from the dishes, the temperature falls. The 
temperature may be kept at 150° C. at the start, and the dishes 
placed only half way upon the plate. As the plate cools, the 
dishes may be pushed over until they are entirely upon the hot 
plate. 

(14.) Rheostat for outside fat plate. Turning rheostat han- 
dle forward increases the temperature. Turning handle back- 
ward decreases the temperature. It is important to see that the 
lever on handle makes good contact with the separate buttons, and 
not with two buttons at a time. As soon as the right button has 
been found that maintains a constant temperature, mark this 
point upon the white plate. When starting up the Tester, the 
handle may be turned on full, and then when the temperature is 
up to within ten degrees of the right point, the handle may be 
turned back to the previously marked button. The same instruc- 
tions apply for all rheostats. 

(15.) Rheostats for the fat oven. 

(16.) Rheostats for the solids oven. 

(17.) Rheostat for the outside solids plate. 

(18.) Handle for the centrifuge. 

(19.) In case the operator forgets the temperature and time 
for treating the samples at the various points, the same may be 
noted below each snap switch for each hot plate. 

(20.) The power unit consists of a high vacuum pump, a 
water circulating pump, and a suction fan, all driven by a single 
motor. The vacuum pump must be submerged in oil furnished 
with the Tester. The pump chamber should be filled with oil up 
to mark upon the air cock. 

(21.) Automatic burettes. The cans holding the water, am- 
monia, alcohol, ethyl ether and petroleum ether are placed in this 



Parts 67 

order. This is the order in which these reagents are added to the 
flasks containing the weighed sample of milk. The water and 
ammonia bottles are graduated to .50 c.c. divisions. The alcohol, 
ethyl ether and petroleum ether burettes are graduated to 5,0 c.c. 
divisions. 

(22.) Place this hood over the fat dishes when evaporating 
off the ether, so that the suction fan may draw ether fumes out- 
side of the building. 

(23.) Fasten these legs to the floor with lag screws. 

(24.) This side need not be fastened to floor. In case it is 
necessary to take out power unit, it is necessary only to disconnect 
connections in the rear of the machine, and move this part of the 
machine forward. 

(25.) The balance is the heart of the machine. Operator must 
keep it level, clean and handle it carefully. Raising and lower- 
ing knife edges must be done gradually and with care. Makg it 
a habit to clean the balance daily. The weights must be kept 
clean, and as soon as you notice that some of the smaller weights 
are wearing out, order new ones. 

(26.) This cock releases the vacuum upon the oven when 
cock (27) is closed. It must be kept closed when the vacuum is 
being maintained in the oven. 

(27.) This cock connects the vacuum oven upon the solids 
side with the main vacuum line leading to the vacuum pump. The 
set of cocks at the left is for the control of the vacuum to the fat 
oven. 

(28.) In top of fat plate holder there is a hole communicating 
with the suction fan upon the power unit. When the exhaust 
pipe connecting with the suction fan is run out of the laboratory, 
and the hood is over the dishes, all fumes of ether will be ex- 
hausted from the room. 

(29.) ScreM stool to floor, 

(30.) A wash stand for washing all glassware should be pro- 
vided. This should be properly designed and conveniently lo- 
cated, and supplied with both hot and cold water. 

In Fig. 19 is given a phantom view of the fat side of the Mo- 
jonnier Milk Tester which aids in a further understanding of the 
function and the arrangement of the various parts. The power 



68 



Asse;mbung Mojonnier Milk Tester 



unit, water tank, centrifuge with head, baskets and extraction 
flasks, and the device for exhausting the ether vapors are espe- 
cially pointed out. 




Fig*. 19. Phantom view fat side Mojonuier Milk Tester. 



Table 16. Dimensions and other eng'ineering' specifications coverlngr the 
Mojonnier IMUlk Tester. 





Floor 
Space 


Height 
Table 
Top 


Height 
Over all 


Shipping 
Weight 


H. P. 

Consumed 


Size of 

Wire 

Required 


Type 


Min. 


Max. 


Model D — For both fat and 
solids with thermostatic 


56 X 82 in. 


35 in. 


68 in. 


1,500 lbs. 


IH 


3 


12 






Model A— For fat and solids 
with rheostatic control .... 


48 X 82 in. 


35 in. 


68 in. 


1,300 lbs. 


IH 


3 


12 


Model G — For fat and solids 
with steam control 


66 X 82 in. 


35 in. 


68 in. 


1,400 lbs. 


1^ 


3 


Pipe 
Inlet J^ in. 



Dimensions 



69 





^ 

o 



5 



c 
,2 

c 

a? 

■-H o 

CO .AJ 

a o 



r> CO 
o 

e 



^ -4-) 



o 






a 

J5 



s: 



ID S 

I 2 

5 3 









c .S 
o a 

g ^ 
t 

3 

u 



o C 



ri 




^ m 






« c 


PO 


CO 

T3 

c 




H 


3 


P 


3 

s 


^ 


o 



CHAPTER V 

THE OPERATION OF THE MOJONNIER 
MILK TESTER 

111 the Mojoiinier Milk Tester, there are several operations 
that remain the same regardless of the product that is being 
tested. The operator should become familiar with every detail 
covering the construction, care and use of the machine. 

General Care of the Tester. Keep the Tester clean and free 
from the accumulation of unnecessary materials at all times. It 
is impossible to do accurate work if the apparatus is not in the 
best of conditiou. All japanned parts can be cleaned either with 
engine oil, applied by a clean cloth, or by washing with good soap 
and water. 

THE POWER UNIT AND THE WATER CIRCULATING UNIT. 

Keep the water tank well filled with water. Add about one 
quart light machine oil to the water in the tank to keep the water 
pump well lubricated. If the Tester is located in a cold room in 
winter, add one gallon denatured alcohol to the tank to prevent 
freezing. 

Keep the vacuum pump chamber properly filled with the right 
kind of oil. The oil should just about reach the top of the pis- 
tons, as indicated by the gauge glass upon the side, or cock upon 
the end, in the earlier models. 

Give the motor proper care. It should receive the same atten- 
tion as is required by any motor, that is, it is to be kept cleaned, 
and well lubricated. 

Should any knocks develop upon the power unit, remedy the 
same immediately. The construction is very simple, and with a 
little study the care and operation of the power unit can be readily 
learned. 

[70] 



Adjusting Temperatures 71 

THE VACUUM OVENS AND COOLERS. 

Keep sufficient mercury in the mercury well to insure good 
contact between the thermometer and the mercury well. The 
mercury well should rest directly upon the hot plate, otherwise 
incorrect temperature will be indicated by the thermometer. If 
mercury is spilled upon the hot plates, remove it at once. Do not 
permit mercury to come in contact with aluminum dishes as this 
may spoil the test. Keep the ground joint between the lid and 
the oven thoroughly cleaned. In case that it is difficult to get the 
proper amount of vacuum, look first to this place for trouble. 
Sometimes it may be necessary to use a small amount of vaseline, 
but as a rule the best results are obtained by keeping the ground 
joints thoroughly clean, using just enough vaseline to provide the 
proper lubrication and to prevent rusting. Be sure that the ther- 
mometer opening, and the openings upon the bottom of the oven 
are thoroughly sealed. It may be necessary to replace the rub- 
ber tubing at these points in case that leakage develops. Be sure 
to see that the cooling dessicators are kept from freezing tempera- 
tures. If the water in the cooling plates should freeze, it would 
ruin the plates. Watch the water coming out of the coolers, in 
order to be sure that the circulation is correct. 

Turning on the Current and Adjusting- Temperatures. It is 

important that the wires connecting with the Tester should be of 
size specified ; namely. No. 12 copper wire. The Tester is provided 
with a main control switch. Turn on the current to heat the out- 
side hot plates and the vacuum oven plates, by means of the snap 
switches. These are properly marked for the guidance of the 
operator. This should be done far enough in advance so that the 
plates and ovens will be heated to the proper temperature, when 
they are needed. The temperatures upon the outside plates in all 
electrically operated models, and in the vacuum ovens upon Model 
A, may be closely regulated by means of the rheostats. If the 
voltage is constant, the temperature will remain very near to the 
point desired for a long period of time after the rheostats have 
been properly adjusted. Ascertain by the tests just where it is 
necessary to hold tlie lever upon the rheostat in order to get the 
required temperature. After this point is once ascertained, the 



72 



OpE;RA'riNG Mojonnie:r Milk Tester 



lever can be set at the point required, and the temperature al- 
lowed to come up automatical!}^ when starting in the morning. 

In the case of Model D the temperature in the two vacuum 
ovens is controlled by thermostats. The method of wiring recom- 
mended is indicated upon Fig, 21. The mercury thermostat rest- 
ing in the mercury well is calibrated at the required temperature, 
and it must be properl}^ connected. 







Tig. 21. Wiring- Diagrams for Thermostatic Control Model D Mojonnier Tester. 
A For Direct Current. B For Alternating- Current. 



Care and Use of the Balance. Keep all parts of the balance 
and case free from dust. A cover placed over the balance at 
night serves a very useful purpose. Dust the balance including 
the pans and weights, using a camel's hair brush for this purpose. 
Level and adjust the balance so that the pointer will oscillate an 
equal number of divisions upon each side of zero upon the pointer 
scale. If the pointer swings too far to the right, turn the adjust- 
ing screw upon the beam to the right. If it swings too far to the 
left, turn the adjusting screw to the left. 

Two types of balances are in principal use : namely, the old 
type with graduated beam and rider, as illustrated under Fig. 22, 
and the new type called ''Chainomatic" with the chain and ver- 
nier, as illustrated under Fig. 23. The care to give to either type 



Operation op Balance 



73 



of balance is the same. The difference is in the method of balanc- 
ing the object to be weighed, and of reading the weight. These 
points will be discussed separately. 

A balance is a delicate instrument, and care needs to be exer- 
cised in its use at all times. The weights likewise require careful 
handling. Lack of care in the weighing operations may lead to 
entirely erroneous results, and thus defeat the object aimed at : 
namely, the accuracy of the tests. 




Tig. 22. Analytical Balance. 

Courtesy of Schaar & Co. 



The balance is enclosed in a glass case to shield it from dust, 
air currents and moisture. Perhaps the largest factor affecting 
accuracy in weighing, granting other conditions to be right, is 
temperature. If the vessel or object to be weighed is of a lower 
temperature than the balance case, it will weigh apparently more 
than its actual weight. If of a higher temperature than the bal- 



74 



Operating MojonniEr Milk Tester 




Fig". 23. Analytical Chainomatic Balance. 

(Courtesy of Christian Becker Co.) 



aiice case, it will weigh apparently less than its actual weight. The 
object should, therefore, be as closely as possible of the same 
temperature as that of the air in the balance case. The water 
cooled desiccator used upon the Mojonnier Tester has been de- 
signed primarily to facilitate the equalizing of the temperature 
between the dishes to be weighed and the balance case. See, there- 
fore, that the temperature of the water in the circulating sj^stem 
is as nearly as possible the same as the temperature in the balance 
case. 

The weights shonld be kept clean, and checked frequently 
either against each other, or against other standard weights. 
Promptly replace any weights that may be off the standard, or 
apply the necessary correction. 



Chainomatic Balance 75 

When necessary to clean the chain, carefvilly detach it from 
the balance. Lay it out straight on a piece of velvet and brush 
it with a camel's hair brush. Then return it to its proper place 
on the balance. A small beaker partly filled with sulphuric acid 
should be kept in one corner of the balance case. Replace the 
sulphuric acid when it becomes saturated with moisture, and be 
very careful never to allow the beaker to overflow. 

Protect the balance against vibration, and see that it is in 
exact level. The air bubble in the spirit level should be in the 
exact center. This can be readily accomplished by means of the 
leveling screws under the balance case. 

The balance should be in exact equilibrium at all times. That 
is, the pointer should oscillate an equal number of divisions upon 
each side of zero upon the pointer scale. If the pointer swings 
too far to the right, turn the adjusting screw upon the beam to 
the right. If it swings too far to the left, turn the adjusting 
screw to the left. 

Place object to be weighed upon the left hand pan, and the 
weights or counterpoises upon the right hand pan. Handle the 
weights with the forceps only, using the right hand. Use the left 
hand to release the beam front the support, and to raise or lower 
the balance door. The weights should be placed upon the pan in 
a systematic order, begiiniing with a weight that is judged to be 
somewhat too heavy. liower weights are then tried in succession 
in a systematic order until equilibrium results. 

Upon the old style balance, adjustments under 5 and 10 milli- 
grams (depending upon the construction of the balance) are made 
by means of the rider. Keep the balance door closed while the 
final adjustment is being made. Determine the relation between 
the divisions upon the rider beam, and the pointer scale. This 
relation varies with different balances, but when once ascertained 
upon a given balance, it remains a constant value, and if applied 
in making a weighing, a great deal of time can be saved. For 
example, if the pointer oscillates six divisions to the right of zero, 
and four divisions to the left, with a balance having a relation of 
.0002 gram to one division upon the pointer scale, the rider is 
moved .0004 gram to the right to bring the balance into equilib- 
rium. 



76 Operating Mojonnier Mii,k Tester 

Upon the Chainomatic Balance, adjustments under .0500 gram 
are made by means of the screw and vernier. Determine the rela- 
tion between the divisions upon the vernier, and the pointer scale. 
If the pointer swings too far to the right, lower the slide, — if too 
far to the left, raise the slide. About .0003 gram upon the vernier 
usually equals one division upon the pointer scale. 

Exercise great care in recording the weights. A double check 
should be made by reading both the weights upon the balance 
pan, and the weights that are missing from the set. The weights 
should be placed upon a paper near the front of the balance case, 
with the values of the weights marked upon the place where the 
respective weights are kept. Kemember that one misread weight 
will spoil an entire test. Upon the Chainomatic Balance read 
weights as follows : 

(a.) Sum of all grams weights equals whole number. 

(b.) Sum of 100 or multiple of 100 milligrams equals first 
decimal. 

(c.) Sum of 10 or multiple of 10 milligrams equals second 
decimal. Out of a possible total of 100 milligrams, 50 milligrams 
are obtained from the fractional weight, and 50 milligrams from 
the vernier beam. 

(d.) The third decimal is obtained from the vernier beam. 
Read the value of the line just above the small upon the slide. 

(e.) The fourth decimal is the value upon the slide that is in 
the exact line with any given line upon the vernier beam. 

THE IMPORTANCE OF SHORT BALANCE SWINGS. 

Much time can be saved by following the proper practice at 
each step of the weighing operation. Long balance swings con- 
sume more time : cannot be read so accurately, and the final result 
is usually not as dependable as when short swings are used. H. L. 
Wells^ made a careful study of the relative merits of long and 
short swings, and concludes in favor of the short swings. The 
best practice is to permit the pointer to swing between 4 and 6 
points upon either side of the zero line. If the swings are much 
shorter than this, the error due to the width of the pointer may 
become considerable. Two complete oscillations only are neces- 
sary — the second being a check upon the first one. Every precau- 



Weighing 



// 



tion .should be taken to speed up the weighing in order that this 
may not affect the accuracy of the results. 

THE INFLUENCE OF TEMPERATURE UPON THE WEIGHING 

RESULTS. 

The temperature factor is too often disregarded. J. J. Mojon- 
nier weighed three aluminum dishes, size about 3" in diameter by 
1" high at various temperatures. The results obtained are given 
in the following table : 

TABLE 17. 
Influence of Temperature Upon the Weight of Aluminum Dishes. 



Dish 
Number. 


Balance 
Temperature 


Wt. Dish at 
32° F. 


Wt. Dish at 
63° F. 


Wt. Dish at 
68° F. 


Wt. Dish at 
92° F. 


4 
3 
2 


68 
68 
68 


10.0200 
10.0110 
10.0128 


10.0126 
10.0043 
10.0029 


10.0108 
10.0028 
10.0012 


10.0000 
9.9915 
9.9900 



This subject was further carefully studied by one of the 
authors at Cornell University.- 

The results of the experiments performed are given in 
Table 18. 

TABLE 18. 

Influence of Temperature Upon Analytical Weights of Various Objects. 





300 c c. 

Aluminum 

dish 


100 c. c. 

Aluminum 

dish 


300 c. c. 

Erlenmeyer 
flask 


"J 

O OS 
o « 
CO ,a 


50 c. c. 

platinum 
dish 


7 aluminum 
discs clamped 
together 


i , 

S « a 
III 


C9 

III 


in 

ti a to 
ci-2.| 


Wt. temperature 
21.5° C 


54.8882 


13.5906 


46.7769 


49.2125 


18.6343 


57.7225 


56.3290 


56.2754 


56.3222 






Wt. temperature 
80° C 


54.8295 


13.5700 


46.7430 


49.1624 


18.6243 


57.7168 


56.2728 


56.2658 


56.2754 






Decrease in weight 
due to increased 
temperature 


.0587 


.0206 


.0339 


.0501 


.0100 


.0057 


.0462 


.0096 


.0468 



The results given in both of the preceding tables prove the 
importance of maintaining uniform temperatures between con- 
tainer and balance when weighing both the empty container and 
in turn the container, after the substance to be weighed has been 
added to it. The colder the object being weighed, the greater 



78 Operating Mojonnitcr Milk Tester 

will be the weight thereof, and vice versa, the warmer the object, 
the smaller the weight thereof if the balance temperature remains 
constant. These facts, if not properly reckoned with, may cause 
large errors in results. With care, the same can be kept under 
close control. 

The principal causes of the above variations are : (a) The in- 
fluence of air currents set in motion because of the higher tem- 
perature of the object being weighed, (b) The displacement of 
air in the container, due to its expansion at the higher tempera- 
tures. In the experiment with the separatory funnel the loss in 
weight from this cause was about 4.6 times greater than the loss 
due to the air currents, (c) Other possible causes include the re- 
cording of incorrect weights ; slight differences in the length of 
the scale beam ; changes in barometric pressure ; changes in the 
temperature of the air in the balance between the weighings, and 
invisible moisture films upon the surface of the container. 

How to Heat the Fat and Solids Dishes Before Weighing^. Give 
to the fat and solids .dishes the same treatment before weighing 
them empty, that is given them before the final weighing in com- 
pleting a determination when they contain the extracted fat or 
the solids from the test. Place the clean fat dishes in the vacuum 
oven at a temperature of 135° C. Turn on the vacuum and leave 
them in the vacuum oven for 5 minutes. Transfer them to the 
cooling desiccator, and with the pump still running, leave them 
therein for 7 minutes before weighing. Be certain that the water 
is circulating through the plate in the cooling desiccator. Place 
the clean solids dishes in the solids ovens at 100^ C. Turn on the 
vacuum, and leave them in the vacuum oven with the vacuum on 
for 5 minutes. Transfer them to, and hold them in the cooling des- 
iccator for 5 minutes while the water circulating pump is running. 

Do not weigh either the fat nor the solids dishes far in advance 
of the time that the same may be required. The principle to keep 
in mind is the necessity of maintaining the same temperature in 
the balance ease at the time of the two weighings. 

How to Weigh the Fat and Solids Dishes. After the dishes 
have remained in the respective cooling desiccator for the proper 
time, they should be promptly transferred to the balance pan and 
weighed accurately to .0001 gram, using the proper counterpoise. 



Weighing 79 

Record the weight and number of each dish in its respective place 
on the laboratory report sheet. Use cover upon solids dish. No 
cover is to be nsed with the fat dish. Return the dishes to the 
cooling: chamber, until needed for the test. 

How to Clean the Dishes and the Glassware. The solids dishes 
should be soaked in water after the test has been completed, and 
the solids then removed by hand, or by means of a brush suited 
to the purpose. They should then be thoroughly washed and 
dried, and placed in the vacuum oven until required for further 
use. Avoid the use of washing powders and alkalies for cleaning 
aluminum. The fat dishes should be treated with steam or very 
hot water until all traces of fat are removed, or they should be 
treated Avith a small quantity of gasoline until the fat is all dis- 
solved, and this treatment repeated for a second time. Finally, 
the dishes are to be cleaned with a dry cloth, and placed in the 
vacuum oven until needed. 

All glassware should be washed either immediately after beings 
used, or it should be placed in Avater until washed. Extraction 
flasks should be thoroughl}- washed with tap water, and then 
washed out with distilled water. If flasks become dirty, wash 
with washing powder and shot, or use washing powder with a 
brush specially designed for this flask. Clean pipettes with brush 
and water. Use washing powder, if necessary. Rinse successively 
with water, alcohol and ether, and then dry by holding at exhaust 
cock leading to the vacuum oven, or place upon the pipette holder 
between fat oven and cooler. 

REFERENCES. 

' Wells, H. L., Analytical M'eighing, Jour. Am. Chem. Socl., Vol. 42. p. 411. 
2H. C. Troy. 



CHAPTER VI 
SAMPLING DAIRY PRODUCTS 

When samples of milk, or any of its products, are taken for 
the purpose of examination or analysis, great care must be exer- 
cised in order to have the samples truly represent the average 
composition of the substance. In ordinary liquid dairy products, 
the fat globules rise toward the surface and form a layer of cream 
whenever the substances remain at rest. Other small particles of 
undissolved substance settle to the bottom. Many of the bacteria 
may be carried in either direction. For these reasons the product 
must be mixed until the different constituents are evenly distrib- 
uted throughout the entire mass. Then the sample must be taken 
immediately. 

ACCESSORIES REQUIRED FOR SAMPLING DAIRY PRODUCTS. 

To insure proper sampling it is necessary to use the proper 
tools. The following figures illustrate the apparatus recommended 
for properly sampling various dairy products. 

Fig. 24. Mojonnier Composite Sample Bottle, 
recommended for collecting and holding either com- 
posite samples, or any other samples to be tested. 
The advantages of this bottle are as follows : 

1. The pure Para rubber stopper fits the mouth 
of the bottle tightly and prevents evaporation, and 
in consequence overreading of butter fat content. 

2. No danger of dropping, misplacing or break- 
ing stopper. 

3. The non-rust chain and copper ring always 
keep the stopper accessible for quick restoppermg. 

4. Can be quickly opened with thumb of hand holding bottle, 
leaving other hand free for pouring in sample of milk. 

5. Sample can be thoroughly shaken and mixed in the bottle 
without danger of loss. 

[80] 




Sampling Instruments 



81 



agfc-» 



[2)0:^ C^iS^ 



'■3^=53 




Fig-. 25. Fig-. 26. 



Fig. 27. 



Fig. 28. 



Fig. 29. 



Fig. 25 illustrates milk thief. This is recommended only for 
sampling fluid milk, principally at the weigh can. If properly 
used it makes it possible to obtain composite samples that are 
representative of the entire lot of milk from which the samples 
were taken. 

Fig. 26 illustrates a small milk dipper, such as is frequently 
used for taking samples at the weigh can. Inasmuch as it holds a 
constant volume, it will not give representative composite samples 
unless the lots of milk are all of uniform weight. 

Fig. 27 illustrates the Scoville and McKay Samplers. These 
are extensively used for sampling both fluid milk and cream. 

Fig. 28 illustrates a common type of sampler for butter. 

Fig. 29 illustrates a satisfactory sampler for cheese. 



82 Sampling Dairy Products 

SAMPLING FLUID MILK. 

Fresh milk or milk only a few hours old may be readily mixed 
by pouring it from one vessel to another a few times or by stirring 
it with a dipper or similar instrument having a handle sufficiently 
long to reach down to the bottom of the container. When the 
cream on the milk has dried until it is flaky or lumpy and part 
of it has become attached to the sides of the container, it may be 
softened by warming it to 95° F. or 100° F. before mixing. Frozen 
milk must be thawed to permit proper mixing before sampling. 
When the fat has separated so that it floats in small granules or 
in lumps on the surface of milk, it cannot be restored to its orig- 
inal flnely divided condition without warming the milk and pass- 
ing it through a homogenizer or viscolizer. The fat that separates 
is lost in ordinar}^ methods of sampling, but it rarely separates in 
cold milk that is free from acid. Therefore, it is to the advan- 
tage of milk producers selling on the fat test to keep their milk 
in good condition so that no fat will separate before the milk is 
tested. 

When sampling milk or its products for the purposes of stand- 
ardization, the method to use in collecting the composite sample 
must be determined by the conditions prevailing at each separate 
plant. In many cases, it may not be necessary to know the exact 
test of the milk, as the batch very frequently may be handled 
upon the basis of the results of the previous day, or by working 
with the finished product only, in which cases the composite sam- 
ple can be dispensed with. Three methods of sampling for the 
purpose of standardizing whole milk are available, as follows: 

(1.) At the weigh can. By taking out with a "milk thief" 
or other similar sampler, a proportional part of the milk from 
each weighing, just before letting out the milk. This method is 
likely to be very inaccurate whenever the milk is partly churned 
or partly frozen, or whenever the milk is improperly mixed in the 
weigh can. It has the further objection that it requires, as a rule, 
an extra man to collect the samples, which, of course, increases 
the operating expense to that extent. 

(2.) In the holding tank, after the milk has been thoroughly 
stirred. This is the ideal method, but it is seldom possible for a 



Sampijng Cream 



83 




plant to collect all the milk in one tank before starting the several 
standardizing operations. 

(3.) By means of a drip sample. The sample to be collected 
from the pipe leading out of the weigh can, or at some suitable 
place upon the pipe line. When possible to apply this method, it 
is probably the simplest and best method of all. However, care 
must be taken to see that the drip operates properly, and that it 
does not get clogged up. Also the sample must be properly pro- 
tected against evaporation and spoilage, since the sample may be 

collecting over a considerable period of 
time. A suggested method for collecting 
a drip sample is illustrated under Fig. 30. 

SAMPLING CREAM. 
The methods employed in sampling 
cream are similar in principle to those 
used in sampling milk. As cream is more 
viscous and flows less freely than milk, 
even more effort and care must be taken 
to insure correct sampling. When cream 
is sampled immediately after separating, 
the fat may be evenly distributed by 
thorough mixing and by pouring it a few times from one vessel 
to another. When the cream is coagulated or lumpy it should be 
passed through a wire sieve or strainer. In some cases it may be 
necessary to warm the cream enough to soften the fat before 
mixing in order to secure a homogeneous product. The sample 
may be taken from the container with a dipper or with a sampling 
tube. When the sample taken is to form part of a composite 
sample, the amount taken from each delivery should always bear 
the same proportion to the mass sampled. Neglecting to do this 
may be the source of large errors. 

COMPOSITE SAMPLES DEFINED. 
As applied to creamery work, a composite sample is made up 
of several portions of milk or cream from a single source, usually 
taken from different days' deliveries, and placed in a bottle with 
a preservative. In condenseries, ice cream plants and commercial 
milk plants where different dairy products are to be mixed to- 
gether, or where all of the products received from different 



Fig-. 30. Method of ol)- 

taining" drip sample from 

milk line. 



84 Sampling Dairy Products 

sources are to be thus mixed, the term "composite sample" may 
refer to a mixture of aliquots (proportionate amounts) from each 
of the masses of substances that are to be united and standardized 
to a definite composition. 

It is seldom necessary to test composite fluid milk samples 
oftener than once a week. Usually they are tested once in two 
weeks. Where possible to preserve them properly the ideal 
method is to test them once a month. This reduces the amount 
of testing to a minimum, saves unnecessary labor and increases 
accuracy. 

PRESERVATIVES FOR COMPOSITE SAMPLES. 

The principal preservatives used for keeping composite sam- 
ples in good condition are mercuric chloride (corrosive sublimate), 
formaldehyde, and potassium bichromate. The use of mercuric 
chloride has generally given good results. It can be purchased 
in tablet form combined with substances that color the milk pink 
or blue to warn people against drinking it as this preservative is 
a deadly poison. Two or three of the tablets serve to preserve 
six or eight ounces of milk for a period of two weeks. 

Formaldehyde is also successfully used for preserving compos- 
ite samples where other preservatives do not completely check 
growth of moulds. It is not such a deadly poison as mercuric 
chloride, but milk samples containing it should be marked "poi- 
sonous." Five or six drops of a 40% solution of formaldehyde 
will preserve six or eight ounces of milk over a period of two 
weeks. "Composite test liquid" is a form of formaldehyde spe- 
cially prepared and colored, for keeping composite samples. It 
is the most economical and the most satisfactory preservative now 
in use. 

Potassium bichromate is not as effective a preservative as the 
others named, but it serves well for holding samples for short 
periods. It is poisonous but not so severe as mercuric chloride. 
For preserving milk samples enough of the bichromate is added 
to give the milk a lemon-yellow color. 

CARE OF COMPOSITE SAMPLES. 

The samples should be kept in trays or on shelves in a cool 
cupboard near the weighing can. Each bottle and its location 
on the shelf should be plainly and correspondingly numbered. 



Composite Samples 85 

When milk is added the bottle should be shaken with a rotary 
motion to soften and to reincorporate, without churning, any 
cream that has risen, and to bring the freshly added milk in con- 
tact with the preservative in solution. The cupboard should be 
closed and locked when sampling is completed for the day. 

PREPARING COMPOSITE SAMPLES FOR TESTING. 

Even with the best care, some cream will become attached to 
the sides of composite sample bottles. Therefore, it is always 
advisable to place the bottles in warm water to soften the cream 
so that it may be quickly removed from the side of the bottle. 
When necessary a suitable brush, or spatula, having a piece of 
rubber tubing drawn over the lower end, can be used to loosen the 
cream from the sides of the bottle. The cream can then be readily 
reincorporated. The contents of the bottle should not be heated 
above 100° F., or part of the fat will separate as an oil, and make it 
extremely difficult to secure an accurate test sample. By bringing 
the water in the warming vessel to a temperature of about 100° 
F. and then placing the bottles in the water, there will be little 
danger of overheating. Figure 31 illustrates a water bath espe- 
cially designed to heat composite sample bottles before testing. 
It is provided with a steam spray pipe, and an overflow so that 
exact control can be maintained over this operation. 



Tig. 31. Composite Sample Bottle Water Bath. 

To properly mix the cream with the milk and obtain repre- 
sentative samples, the addition of a small quantity of shot to the 
bottle before heating and shaking will insure a satisfactory emul- 

COMPOSITE CREAM SAMPLES. 

The practice of taking composite samples of cream has nearly 
ceased in recent years, as more accurate results are secured by 



86 Sampunc. Dairy Products 

testing each sample the day it is taken. With such a valuable 
product as cream, the higher degree of accuracy secured by the 
daily test offsets the additional expenses. When composite sam- 
ples of cream are taken, the directions given above for composite 
milk samples will apply in every detail. 

SAMPLING SKIM-MILK. 

Skim-milk should be mixed before sampling in the same man- 
ner as whole milk. Samples taken from a separator spout at a 
single instance usually will not show the average composition of 
the total quantity separated. After separation is completed, pro- 
portionate amounts should be taken from each container and 
mixed together. The test secured on such a mixture will be the 
average of the entire mass. The same should be kept in air tight 
sample jars in a cool place until they are tested. 

SAMPLING WHOLE MILK FOR MAKING EVAPORATED MILK, OR 
SWEETENED CONDENSED MILK. 

In addition to the directions given on pages 82-83 for sam- 
pling whole milk, the following will be of assistance in sampling 
when testing, in evaporated or condensed milk plants. Secure 
samples from the holding tanks after the milk has been thoroughly 
stirred. This is the ideal method, but it is seldom possible for a 
plant to collect in one tank all the milk required to make up one 
batch. In some cases, more than one holding tank is available, 
and the same can be filled alternately with the whole milk. Sam- 
ples are taken out of the alternate tanks in the proportion of 1 
c.c. to each one hundred pounds of milk in the tank. For exam- 
ple, a tank holding eight thousand pounds of milk will require an 
80 c. c. sample. Samples from the different tanks that go to make 
up the entire holdover l:)atch can be mixed together before testing 
the same for fat and total solids. The objection to this method 
is that it is seldom possible to allow the milk to accumulate in the 
tanks in any fixed quantity since it is usually necessary to pump 
it into the hot wells as soon as it starts accumulating in the hold- 
ing tanks. 

At the hot wells : If the samples are taken at the hot wells, care 
must be taken that no milk remains in the wells from the previous 
batch. Also care must be taken that the milk be well stirred be- 



Sampling Condensed Milk 87 

fore the sample is taken, and that the sample taken be propor- 
tional to the entire weight of milk in the different hot wells. This 
is a good method, provided the milk in the hot wells can be prop- 
erly stirred, but it cannot be used in the case of sweetened con- 
densed milk, on account of the sugar remaining in the hot wells. 

SAMPLING EVAPORATED MILK AND SWEETENED CONDENSED 

MILK. 

Evaporated milk requires to be sampled and tested both before 
and after sterilizing. Samples taken from a pan batch should be 
collected in a well-stoppered bottle as illustrated under Fig. 24. 
The sample should be promptly cooled to about room temperature 
and well mixed before testing. 

Where the holdover sj^stem is used, great care must be taken 
to secure proper mixing of the entire lot of milk in the holdover 
tank. The method of agitation used should be proved by testing 
samples taken from different parts of the holdover batch. 

Samples after sterilizing should be properly mixed in the can. 
Samples in which the butter fat has separated or has become 
churned require special attention, and it frequently becomes im- 
possible to make an accurate test on account of the mechanical 
condition of the sample. 

Skimmed or whole unsweetened condensed milk are usually 
sampled in a manner similar to evaporated milk. 

Sweetened condensed milk in its several varieties is a product 
that requires very particular care in sampling. A sample from a 
pan batch should be collected in a well-stoppered bottle and 
promptly cooled. A sample from a large holdover batch should 
be taken only when the agitation is complete. Samples taken 
from cans, or from barrels, require particular attention on ac- 
count of the possibility of the milk sugar settling upon the bottom 
of the containers. Unless the milk sugar is thoroughly reincor- 
porated, it becomes impossible to obtain a test that is representa- 
tive of the original milk. 

SAMPLING FOR ICE CREAM MIX. 

Methods for sampling cream and other materials to be used in 
compounding the ice cream mix will be found under the directions 
for sampling the respective products. The methods of sampling 
the mix to determine its composition will vary according to the 



88 Sampling Dairy Products 

conditions peculiar to each plant. Where a homogenizer is used, 
some operators prefer to take the sample from the cooling coils a 
few minutes after the homogenizer has started. The mix is then 
in excellent condition for sampling. Other operators may prefer 
to take the sample from the pasteurizer before homogenizing. In 
the latter case, care should be exercised to make certain that the 
mixture is homogeneous throughout. When neither pasteurizer 
nor homogenizer is used, dependence must be placed upon ordi- 
nary methods of mixing to prepare the batch for sampling. Three 
ounce or four ounce samples of the mix should be taken with a 
sampling tube or dipper and placed in air-tight, glass sample 
bottles until tested. 

SAMPLING THE FROZEN PRODUCT. 

There is some tendency for the heavier substances to descend, 
and for the fat percentages to increase in the upper layers of ice 
cream held in storage. Therefore, care must be exercised in order 
to secure representative samples. Where the mass is large the 
sample may be taken with an instrument like a butter trier, draw- 
ing a column of the ice cream extending from the top to the bot- 
tom of the container. Bricks of ice cream may be sampled by 
drQMdng plugs with a trier or preferabl.y by taking the whole of 
a ' vice about half an inch in thickness across the brick, and at 
le'-'st an inch from the end. Frozen samples should be melted 
gradually before testing. 

SAMPLING RUTTER. 

The sampling of butter is one of the most important and diffi- 
cult operations in the process of determining its composition. 
This is so because the water and salt are not evenly distributed 
throughout the fat. The moisture content of the butter in one 
end of a churn will be different from the content in the other 
end. The fat percentage near the surface of a tub of butter, or 
the surface of a pound print, will be higher than it is at the bot- 
tom of the tub or at the center of the pound print. For these 
reasons, care and judgment must be used in taking the sample. 
The method of sampling varies according to the condition and 
location of the butter. When sampling butter in the churn, take 
with a spatula or butter knife ten or twelve one-fourth ounce 
•portions from different parts of the churning and place them to- 



SaMPIvING Chi^sse 



89 



gether in a glass sample jar that has an air-tight stopper. If the 
butter is in tubs, the sample may be taken with a butter trier. 
It is best to take drawings — one from near the edge, one halfway 
between the edge and the middle, and one from the middle. The 
different drawings are placed together in a sample bottle. Some- 
times after the cover is removed the tub is turned upside down 
and lifted off the butter. A one-half pound wedge-shaped 
piece of the butter is then taken from one side about half-way 
between the bottom and the top. Prints may be sampled by tak- 
ing two or three drawings with a trier or by taking a three-ounce 
slice across the print about an inch from one end. 

SAMPLING BUTTERMILK. 

In sampling buttermilk, use the same methods and precautions 
that are given for sampling whole milk and skim-milk on pages 
82-85. 

SAMPLING CHEESE. 

The percentage of moisture in cheddar and other hard cheese 
is highest near the center, while the percentage of fat and other 
solids is highest near the outside. For these reasons considerable 
care and skill is required to take a truly representative sample 
without destroying the cheese. The moisture determination given 
in Table 19 was compiled by one of the authors. It gives the 
distribution of moisture in a cheddar cheese at intervals over a 
period of twenty-one days after the cheese was taken from the 
press and while it was on the shelves in a fairly cool curing room. 
The cheese was not coated with paraffine. 

TABLE 19. 

The Distribution of Water in a Cheddar Cheese and the Loss of Water by 

Evaporation. Results Obtained by Prof. H. C. Troy. 



Age of 
cheese. 


Inner third of 
the plug. 


Middle third of 
the plug. 


Outer third of 
the plug. 


Average. 


1 day 


37.57 


36.78 


35.69 


36.65 


3 " 


36.90 


36.43 


35.08 


36.13 


7 " 


36.81 


36.59 


34.95 


36.11 


9 " 


36.50 


36.62 


35.00 


36.04 


11 " 


36.56 


36.55 


34.50 


35.87 


14 " 


36.54 


36.49 


34.45 


35.82 


17 " 


36.30 


36.39 


34.41 


35.66 


21 " 


36.47 


36.44 


34.10 


35.67 



90 Sampling Dairy Products 

The simplest and best method to take a sample of a cheddar 
cheese is to cut out a wedge-shaped piece reaching from the cir- 
cumference to the center. The sample should be placed immedi- 
ately in a sample jar having an air-tight stopper. 

When it is necessary to take samples without destroying the 
cheese, draw from the upper side with a cheese trier, — three plugs, 
one about one inch from the outer rim, one at the center and one 
half-way between the other two. The plug should extend half- 
Avay through the cheese. After drawing the plugs, break off a 
piece of each plug at the outer end, and close the openings with 
them. The remainder of the plugs will serve as the sample, and 
they should be placed in the sample jars, and the jars closed at 
once. 

Disc-shaped soft cheese may be sampled by taking a wedge- 
shape piece extending from the rim to the center. Square-shaped 
soft cheese are sampled by taking a slice across the cheese some 
distance in from one end. 

Samples of hard cheese like cheddar are prepared for testing 
by passing them through a meat chopper or by cutting the cheese 
into particles about the size of kernels of wheat. This may be 
done in the sample bottle by using the end of a table knife that 
has been squared and sharpened. Before taking the final test 
portion, the contents of the bottle should be well mixed. The soft 
cheese sample is prepared for testing by mixing it in the sample 
bottle, using a spfitula or knife blade for this purpose. Excellent 
results are obtained by grinding the sample in a close-grained 
mortar with a pestle. This must be done rapidly so that there 
may be no loss of moisture from this operation. 

SAMPLING WHEY. 

Whey should be well mixed before sampling. The absence of 
large amounts of casein permits the fat in whey to rise quickly. 
It is practically impossible to reincorporate all of the fat that 
rises to the surface, and for this reason fat tests of whey usually 
show less rather than more fat than the whey contains. Also the 
particles of .casein settle to the bottom quickly and carry down 
with them any incorporated fat. The manufacturing processes of 



Sampling Powdered Products 91 

numerous varieties of cheese are influenced by the percentage of 
acids in the whey. For this reason alone the whey has to be sam- 
pled and tested for acidity frequently during the advancement of 
the manufacturing process. In the process of manufacturing 
cheddar cheese, the whey is sampled immediately before heating 
the curd, previous to removing the whey, and while the curd is 
piled, before being milled, and finally also before salting. 

As test samples of whey are usually taken by volume, the most 
satisfactory way is to take them Avith a graduated pipette from 
the mass to be sampled immediately after it is mixed. It may then 
be transferred directly to the vessel in which the test is to be com- 
pleted. If a sample bottle is used much of the fat may be lost by 
becoming attached to the sides of the bottle. 

SAMPLING OTHER CONCENTRATED DAIRY PRODUCTS. 

When exposed to the air, milk powder absorbs moisture rap- 
idly. This makes thorough mixing of the sample especially nec- 
essary when the powder is not kept in moisture proof containers. 
When it is kept in cans it should be well mixed, and if lumps are 
present it should be put through a sieve before mixing. Some- 
times the powder is mixed, then divided into four approximately 
equal parts. Portions from each quarter are then mixed to- 
gether and the sample, taken, or the quartering process may be 
carried further. 

Sampling Whole Milk Powder. Whole milk powder is sampled 
in the same manner as skim-milk powder. 

Sampling- Malted Milk. Malted milk is sampled by the method 
given for sampling skim-milk powder. 

Sampling- Milk Chocolate. Milk chocolate cannot be ground to 
a powder as it will soften into a paste in the process. Therefore 
it must be shaved or grated into fine particles to permit thorough 
mixing before taking a test sample. 

Frequently the chocolate can be pounded to a smooth, homo- 
geneous mass, in a mortar, with a pestle. 



92 Samsung Dairy Products 

Sampling' Cocoa. Since cocoa is usually held in the form of a 
powder, it may be sampled by the methods given for sampling 
milk powder. 



CHAPTER VII 

DIRECTIONS FOR MAKING FAT TESTS, USING 
THE MOJONNIER TESTER 

OUTLINE OF METHOD. 

The method for making fat tests upon the Mojonnier Tester 
is a comparatively simple one. It is modified for various dairy 
products, but the principles and the general operations remain 
unchanged. In the case of fresh milk the method in brief is as 
follows : 

Measure 10 grams of milk into the extraction flask illustrated 
under Fig. 32. Add 1.5 c. c. of ammonia and mix in small bulb of 
flask. Add 10 c. c. of 95 per cent alcohol, insert cork and shake 
thoroughly. Add 25 c. c. of ethyl ether, and shake for 20 seconds. 
Then add 25 c. c. petroleum ether and shake for 20 seconds. Place 
the extraction flask in the holder of the centrifuge and turn the 
handle 30 turns, taking about one-half minute. This will give a 
speed of 600 revolutions per minute. The centrifuge with the 
holder is illustrated in Fig. 19, Chapter IV. Pour off the ether 
solution from the remainder of the liquid into the fat dish. Evapo- 
rate the ether from the dish, illustrated under Fig. 33. 





Pigr. 32. Fat Extraction Flask. Tig. 33. Fat Dish. 

Repeat the extraction, adding in turn with thorough shaking 
after each addition, 5 e. c. of alcohol, 15 c. c. of ethyl, and 15 c. c. 
of petroleum ether. Centrifuge as before. Add water if neces- 
sary to raise the dividing line between the ether solution, and the 
remaining liquid residue. Pour off the ether solution into the 

' [93] 



94 



MojoNNiER Fat Test 



same dish as was used for the first extraction. Evaporate the 
ether from the dish. Dry the fat in the vacuum oven. Cool and 
weigh the dish. Calculate the percentage of fat in the sample. 
The necessary modifications of the above method for the vari- 
ous dairy products will be discussed further in this chapter. The 
successive steps involved will also be discussed in careful detail. 

HOW TO WEIGH THE SAMPLES FOR THE FAT TEST. 

Several methods are in use for weighing the samples for the 
fat test, depending upon the product that is being tested. The 
weighing cross with the short pipettes can be used successfully 
upon a number of dairy products. Numerous advantages are 
gained by using the cross, provided the product to be tested 
permits of its use. Five different samples can be weighed with 
only six weighings, and if care is taken, great accuracy is obtain- 
able. The following cuts illustrate just how the weighing pipettes 
and the weighing cross are used. 



GIO 



^^=^ 



Q9 



G8 



G7 






T28A TaSB 

rifft 34, Weig-hing' Cross with Rubbers and Pipettes. Also lO-grram Fipettet 



Pipettes 



95 



G 7, G 8 and G 9 illustrate 1, 2 and 5 gram pipettes, respective- 
ly. G 10 is a pipette graduated to deliver 10 grams of whole milk, 
and it is never used in connection with the weighing cross, T 28 
illustrates the cross itself, with the arms all properly numbered, 
in order to distinguish between the samples. T 28A shows the 
cross with the rubber tubes inserted over the knobs, thus forming 
an air-tight seal. T 28B shows the pipettes inserted in the tubes. 

Another very satisfactory method of weighing certain dairy 
products is b}^ means of Weighing Pipettes. These are illustrated 
under Fig. 35. 




G51 G52 G53 T116 

Fig-. 35. Weig-hlngr Pipettes with Holder. 



G 51, G 52 and G 53 illustrate 1, 2 and 
5 gram pipettes, respectively. T 116 illus- 
trates the holder that is to be placed upon 
the balance pan with the pipettes. With 
this method also, five samples can be 
weighed with only six weighings. 




Fig-. 36. 
Position of Weig-h- 
Ing' Pipette Before 
Placing- in Holder. 



96 



MojoNNiER Fat Te;st 



Products that are not homogeneous or that separate rapidly, 
are weighed most accurately when placed directly into the extrac- 
tion flask, while the latter is suspended to the arm of the balance. 
This is illustrated under Fig. 37. 





Right Way 



Wrong Way 



Pigf. 37. — Plask Hangrer with Plask 
Suspended to Balance Arm. 




Fig. 38 is a hanger, one end of which is fastened to 
the hook upon the balance arm and the other holds the 
flask around its neck. 

To insure absolutely accurate results, the extraction 
flask at the time of weighing must have the same tem- 
piask Hang-er. perature as that of the balance case, and the weighings 
of the empty flask and the flask when it contains the sample must 
be made quickly and closely together. In order not to expand 
the air inside the flask between the weighings, the flask should 
not be held in the hands nor allowed to change temperature by 
any other means. 



Adding Reage;nts 



9; 



Butter, and all other products that are not hygroscopic, are 
weighed with great accuracy in the butter boat illustrated un- 
der Fig. 39. 



n: 



Fig-. 39. Butter Boat. 



The butter boat is weighed empty, the sample is then placed in 
it, and the weight obtained by difference. 

Several products can be pipetted out, taking ten grams and 
where possible, this is a very accurate method. The pipettes are 
graduated to discharge ten grams of whole milk at 60° F., allow- 
ing 15 seconds for draining the pipette after the milk has all run 
out, and then blowing out the last drop of milk in the pipette. 

WEIGHT OF SAMPLES TO TAKE FOR THE FAT TEST. 

The size of sample to use varies, depending upon the product 
being tested, and it ranges from one gram in the case of butter to 
ten grams in the case of raw milk. See instructions following 
each product, and also Table 21 at the end of this chapter. 

HOW TO ADD THE REAGENTS. 

The reagents should 
be added in the follow- 
ing order : Water, am- 
monia, alcohol, ethyl 
ether, and petroleum 
ether, The burettes 
upon the dispensing cans are gradu- 
ated to deliver the proper charge re- 
quired. See instruction under each prod- 
uct, and also Table 21 at the close of this 
chapter. 

Fig. 40 shows position of flask when 
adding reagents, when one or two tests are 
being made. Fig. 41 on next page shows pref- 
erable metliod of adding reagents when sev- 

Fig*. 40. 

Adding- Reagents ^^'^^ Samples are to be tested. 




98 



MojoNNiER Fat Test 




Pig-. 41. 

Correct Position of 
Plask Holder and 
Plasks for Adding- Be> 
ag-ents When Making- 
Pour Tests at One 
Time. 



HOW TO SHAKE THE FLASK. 

If only one sample is being 
tested, it can be shaken by 
hand. As many as four samples 
can be shaken at one time in the 
holders which are furnished 
with the equipment. The flask 
should be held with large bulb 
down (see Fig. 42), and the 
small bulb extending upward. 
In this position they are shaken 
vigorously lengthwise of flask. 
After shaking 5 or 6 times, allow liquid in small bulb to run back 
into large bulb. Repeat this operation at least four times. There 
is no "danger in shaking the samples too much. The only danger 
is in not shaking the samples enough so that this is a very impor- 




Pig-. 42. 



Correct Position of Plask 
When Shaking-. 



Mixing Rkagents 



99 



tant part of the operation. Fig. 43 illustrates the extraction 
flask holder by means of which four samples can be shaken at one 
time. 

The flasks should be kept in the position indicated while shak- 
ing and the liquid allowed to flow alternately from the large to 
the small bulb. 




Fig'. 43. Illustrates the Position in Which to Hold the Four Flasks That Are 
Being Shaken at One Time. 



HOW TO CENTRIFUGE THE FLASK. 

If only one sample is being centrifuged at a time, place a coun- 
terpoise upon the opposite side of the centrifuge in order to bal- 
ance the head. Always see that there is about the same weight 
upon both sides of the centrifuge. The centrifuge with the head, 
holder and flask is illustrated under Fig. 19, Chapter IV. 

HOW TO POUR OFF THE ETHER SOLUTIONS. 

Remove the cork by twisting it carefully from the flask. Pour 
off the ether solution as completely as possible, taking care not to 
allow any of the liquid under tlie ether to flow out of the flask. 
This can be avoided if the dividing line between the ether solu- 
tion and the remaining solution is carefully Avatched, while pour- 
ing off. In the first extraction, a larger amount of the ether so- 
lution can remain in the flask than in the second extraction. The 



100 



MojoNNiER Fat Test 



correct procedure in pouring off is illustrated under Fig, 44. 
The fat dish should be placed upon the tester top, and the opera- 
tor should look down upon the ether solution as it is being poured 
off, observing the point where all the ether has been removed. 

By following this 
method, all but one or 
two drops of the ether 
solution should be re- 
moved, provided the 
dividing line was in 
the right place before 
pouring out. 




Pigr. 44. 



Correct Procedure When Pourings 
Ether Solution Into Dish. 



HOW TO BRING UP THE DIVIDING LINE 



Inability to pour off the ether solu- 
tion closely is due to the fact that the 
dividing line between the ether solu- 
tion, and the remaining solution is too 
low in the lower bulb of the flask. At 
the end of the first extraction, the 
dividing line can re- 
main without change, 
taking care to pour off 
the ether solution as 
closely as possible, re- 
gardless of the posi- 
tion of the dividing 
line. At the end of 
the second extraction, 
remove the stopper from the flask, and drop sufficient distilled 
water from the burette into the extraction flask to raise the 
dividing line to the desired point. This should be done just 
before pouring off the ether. If this procedure is followed, it 
becomes possible to remove the ether almost to the last drop. 
Fig, 45 shows the position of the dividing line both before and 
after water is added. 




After 



Before 



Figr. 45. Position of Dividing' £ine 
Before and After Baising. 



Evaporating Ether 



101 



HOW TO EVAPORATE THE ETHER FROM THE DISH. 

It is important to maintain the proper temperature upon the 
outside hot plate. If the temperature is allowed to go below 
135° C, it takes too long to evaporate the ether solution. Upon 
the other hand, if it rises much above 135" C, there is danger of 
the ether boiling out over the top of the dish, and also slight 
danger of oxidation of the fat. If the plate is too hot, it is 
best to place only part of the dish in contact with the plate. It is 
recommended that the hood be placed over the dishes, and that the 
ether fumes be blown out of the room by means of the blower. It 
is dangerous to allow the ether fumes to evaporate into the work- 
ing room, and besides it makes it very unpleasant for the operator 
to work in contact with these vapors. This method is illustrated 
under Fig. 46. 




Fig'. 46. Evaporating the Ether. 




Fig. 47. Transferring" Dishes to Vacnum Oven, 



102 



MojoNNiER Fat Test 



HOW TO HEAT THE FAT DISH IN THE OVEN. 

Do not transfer the fat dish from the outside hot plate to the 
vacuum oven until all of the ether has been evaporated. 
If this is not done, the contents of the dish are quite likely to spat- 
ter in the oven. It is very important to maintain proper tempera- 
ture conditions, namely 135° C, and also the proper vacuum upon 
the fat dishes, while the same are being heated in the oven. If 
for any reason, there should be difficulty in attaining either the 
proper heat, or the proper vacuum, the trouble should be immedi- 
ately investigated and its cause removed. 




Wrong W^ay Right Way 

Fig". 48. Method of Flacingr Dish Upon the Balance Fan. 



HOW TO WEIGH THE FAT DISH. 

The fat dishes are to be transferred from the vacuum oven to 
the cooling desiccator in which they are to remain for seven min- 
utes before being weighed. The weighing should be done as 
promptly as possible after cooling. Allow as little time as possible 
to elapse between the weighing of the empty dish, and of the dish 
with the fat in it. The air in the cooling desiccator should be at 
the same temperature as the air in the balance case. Therefore 
the two should be located closely together. 



CoNTROLtINC THK VaCUUMS 



103 



DIRECTIONS FOR OPERATING LEVERS CONTROLLING THE 
VACUUM OVENS. 




















L 




f i- 




1 




Tig. 49. Valve Handles Controlling' Vacuums in Fat and Solids Ovens 

Move valve handles in positions corresponding to lettering in 
above diagram as follows : 



For no vacuum in eitlier oven.... A, B and C, D 

For vacuum in fat oven A^ B and C, D^ 

For vacuum in Solids oven A, B^ and C\ D 

For vacuum in botli ovens A, B^ and C, D^ 



104 



MojoNNiER F'at Test 



IMPORTANT HINTS TO OPERATORS OF THE MOJONNIER MILK 

TESTER. 




FiiT- 50 



When Fillingr Water Tank Use Bub- 
taer Tube and Siphon Water as Illus- 
trated. A Iiittle Water Soluble Oil 
Placed in the Water Will Prolong' Iiife 
of Gears in Water Circulating^ Fump. 



Fig. 



When Filling Vacuum Pump 
Reservoir Fill Spouted Dipper Fur- 
nished with Tester and Four as Il- 
lustrated Until Proper Iievel of Oil 
is Indicated in Oil Gauge. 




Fig-. 52. Place the Calcium Chloride Fan Under the Plate In the Cooling 
Desiccator, as Illustrated. 



Laboratory Re;port 



105 



HOW TO RECORD THE RESULTS AND TO CALCULATE THE 
PERCENTAGE OF FAT. 

A systematic method should be adopted for recording all data 
covering the fat tests. Pig. 53 shows a form of laboratory 
report suitable for recording both fat and total solids tests. 



LABORATORY REPORT 



^r 
















1 




1 




... 1 1 


j 


rj.^r 1 




1 


r.«TTM 














1 1 1 




-i. 1 1 i 1 1 


-= — 






1 1 1 1 1 




! ! I 1 1 




! 1 1 1 1 


'"".IIW"' 


1 1 1 ! 1 




i i 1 1 1 




1 1 1 i 




,oI. 1 1 ! 1 












o«™« 



Fig-. 53. Iiaboratory Report Blank. 



Dish plus Fat 

Dish 

Fat 



TABLE 20. 
Laboratory Report. Test No. 1 
September 1, 1920. 

Evaporated 
milk. 
4287 



0163 

4124 

Pipettes plus Sample 32.8200 

Pipettes 27.6650 

Sample 5.1550 

Percentage of Fat 8.0000 



Evaporated 
milk. 
.2550 



Dish plus Solids 

Dish 0124 

Solids 2426 

Dish or Pipette, plus sample. .9401 

Dish or Pipette 0124 

Sample .9277 



Percentage of Solids 26.1500 

In order to obtain the per cent of fat in the sample, divide the 
weight of the fat in the dish by the weight of the sample taken. 
Multiply the result thus obtained by 100 or move the decimal point 



106 MojoNNiER Fat Tkst 

two places to the right. Example : Weight of fat found equals 
,4124 gram. Weight of sample taken equals 5.1550 grams. .4124 
divided by 5.1550 equals .0800. .0800 multiplied by 100 equals 
8.00 or the percentage of fat in the sample. 

HOW TO RUN BLANKS UPON REAGENTS. 

■ It is of the utmost importance to use pure reagents, or to 
make the proper corrections when using reagents that contain 
impurities. 

To prove the purity of the reagents, blank determinations 
should be made at frequent intervals. Measure 50 c. c. each of 
ethyl and petroleum ether in separate fat dishes. Evaporate, 
heat, cool and weigh the dishes in exactly the same manner as 
when making a fat test. The residue should not exceed .0005 
gram, which is equal to an error of .01 per cent upon a five gram 
sample. In a second method measure 10 c. c. of water in a fat ex- 
traction flask, and add all the reagents and complete the test just 
as in the case of a fat test upon whole milk. The residue in this 
case also should not exceed .0005 gram. If the residue exceeds 
the above limits, trace the trouble to the particular reagent that is 
responsible for the residue present, and take immediate steps to 
correct the trouble. Refer to Chapter III. 

HOW TO TEST FRESH MILK, SKIM-MILK, WHEY AND 
BUTTERMILK FOR FAT. 

Mix the samples very thoroughly. Measure samples for the 
test, taking 10-gram sample and using the 10-gram pipette. Drain 
the pipette 15 seconds, counting from the time the milk has all 
run out. Then gently blow out the last drop. If it is preferred, 
the samples can be weighed, although this constitutes an unneces- 
sary operation. 

Add no water to the samples. 

For the first extraction, add 1.5 c. c. of ammonia ; 10 c. c, of 
alcohol ; 25 c. c. of ethyl ether, and 25 c. c. of petroleum ether. 
Shake thoroughly after the addition of the ammonia, half a minute 
after the addition of the alcohol, and one minute after the addi- 
tion of each of the two ethers. 

Centrifuge 30 turns, taking one-half minute. 

For the second extraction, add neither water nor ammonia. 



Evaporated Milk Test 107 

Add 5 e. c. of alcohol ; 15 c. c. each of ethyl and petroleum ethers, 
and shake 20 seconds after the addition of each reagent. 

Centrifuge 30 turns, taking one-half minute. 

If necessary to raise the dividing line between the two ether 
solutions, add the necessary distilled water just before pouring 
off. 

After evaporating off the ether, heat the dishes with the fat, 
in the vacuum oven at 135° C. for five minutes with not less than 
20" of vacuum. Cool in cooling desiccator to room temperature 
for seven minutes. 

Weigh rapidly. Record results and calculate the percentage 
of fat. 

HOW TO TEST EVAPORATED MILK, CONDENSED BUTTERMILK 
AND ALL UNSWEETENED CONDENSED MILKS FOR FAT. 

Unsweetened condensed milk or evaporated milk, whether un- 
sterilized or sterilized is all tested for fat in yery much the same 
manner. Superheated plain bulk condensed is difficult to sample 
properly, so that great care must be exercised in getting represen- 
tative samples. Evaporated milk sterilized in the can, especiall.y 
after standing for a considerable time sometimes contains the fat, 
either separated in the form of cream or in the form of churned 
fat. Samples in this condition are difficult to test, and the proper 
allowance should always be made in cases of this kind. 

To weigh the sample use either the weighing cross, or the 
weighing pipettes, and in some cases it may be desirable to weigh 
the sample directly into the flask suspended from the balance arm. 
The last method would apply where the samples are not homo- 
geneous. Use about 5-gram sample, excepting in the case of con- 
densed buttermilk and of extra heavy superheated milk, when 
only 3 grams should be used. 

For the first extraction, add 4 c. c. of water (except in the ease 
of condensed buttermilk and of extra heavy superheated milk 
when 6 c. c. of water should be used). 1.5 c. c. of ammonia, 10 
c. c. of alcohol, and 25 c. c. each of ethyl and petroleum ethers. 
Shake thoroughly after the addition of water ; again after adding 
the ammonia ; half a minute after the addition of the alcohol and 
20 seconds after the addition of each of the two ethers. 

Centrifuge 30 turns, taking one-half minute. 



108 MojoNNiER Fat Test 

kill ill i.liii! ' 

For the second extraction, add neither water nor ammonia. 
Add 5 c. c. of alcohol, 25 c, c. each of ethyl and petroleum ethers, 
and shake 20 seconds after the addition of each reagent. (In the 
ease of plain condensed skim-milk, and condensed buttermilk, use 
only 15 c. c. of each ethers in the second extraction.) 

Centrifuge 30 turns, taking one-half minute. 

If necessary to raise the dividing line, add the necessary dis- 
tilled water just before pouring off the ether solution in the sec- 
ond extraction. 

After evaporating off the ether, heat the dish with the fat in 
the vacuum oven at 135° C. for 5 minutes with not less than 20 
inches of vacuum. Cool in the cooling desiccator to room tem- 
perature for 7 minutes. 

Weigh rapidly. Record results, and calculate the percentage 
of fat. 

HOW TO TEST SWEETENED CONDENSED MILK FOR FAT. 

Proceed without diluting the sample, but be sure to obtain a 
representative sample, and to make sure that the sample is prop- 
erly and thoroughly mixed. Sweetened condensed milk is very 
difficult to sample properly on account of the tendency for the 
milk sugar to settle out. 

To weigh the sample, use either the weighing cross, or the 
weighing pipette. Use about five grams sample. 

For the first extraction, add 8 c. c. of hot water; 1,5 e. c. of 
ammonia ; 10 c. c. of alcohol, and 25 c. c. each of ethyl and petro- 
leum ethers. Shake very thoroughly after adding the water, and 
again after adding the ammonia, and one minute each after adding 
the alcohol, and the two ethers. 

Centrifuge 60 turns, taking one minute. 

For the second extraction, add neither water nor ammonia. 
Add 5 c. c. of alcohol, 25 c. c. each of ethyl and petroleum ethers, 
and shake 20 seconds after the addition of each of the reagents. 
Centrifuge 60 turns, taking one minute. 

If necessary to raise the dividing line, add the necessary dis- 
tilled water just before pouring off. 

After evaporating off the ether, heat the dish with the fat, in 
the vacuum oven at 185° C. for 5 minutes, with not less than 20 
inches of vacuum. Cool in the cooling desiccator for 7 minutes. 



Ice Cream Mix Test 109 

"Weigh rapidly. Record results and calculate the percentage 
of fat. 

HOW TO TEST ICE CREAM MIX FOR FAT. 

Mix the sample very thoroughly, and if necessary heat the 
same slightly in order to melt the butterfat. If the sample is not 
homogeneous, great care must be exercised in weighing out the 
same, otherwise the accuracy of the results will be affected. Weigh 
the sample, using either the weighing cross or the weighing 
pipettes, and in case that the sample is not homogeneous, weigh 
the sample directly into the extraction flask suspended from the 
balance arm. Use about five grams sample. 

For the first extraction, add 5 c. c. of water, 1.5 c. c. of ammo- 
nia, 10 c. c. of alcohol, and 25 c. c. each of ethyl and petroleum 
ethers. Shake thoroughly after adding water, and again after 
adding the ammonia, and one-half minute each after adding the 
alcohol and the two ethers. 

Centrifuge 30 turns, taking one-half minute. 

For the second extraction, add neither water nor ammonia. 
Add 5 c. c. of alcohol, 25 c. c. each of ethyl and petroleum ethers, 
and shake 20 seconds after the addition of each reagent. 

Centrifuge 30 turns, taking one-half minute. 

If necessary to raise the dividing line, add the necessary dis- 
tilled water just before pouring off the ether solution. 

After evaporating off the ether, heat the dish with the fat, in 
the vacuum oven at 135° C. for 5 minutes with not less than 20 
inches of vacuum. Cool in the cooling desiccator at room tem- 
perature for 7 minutes. 

Weigh rapidly. Record results and calculate the percentage 
of fat. 

HOW TO TEST CREAM FOR FAT. 

Mix the sample very thoroughly, and heat it slightly, if this 
should be necessary, in order to melt the fat. To weigh the sam- 
ple, use either the weighing cross or the weighing pipettes, and if 
the sample is not homogeneous, use either the butter boat or weigh 
the sample directly into the extraction flask suspended on the bal- 
ance arm. In the case of cream testing less than 25 per cent of 
fat, use two grams sample, and in the case of cream testing more 
than 25 per cent of fat, use one gram sample. 



no MojoNNiUR P'at Test 

For the first extraction, add 5 cc. of water, in the case of 
cream testing less than 25 per cent. Add 6 c. c. of water, in the 
case of cream testing more than 25 per cent of fat. Shake thor- 
oughly after the addition of the water. 

Use also 1.5 c. c. of ammonia, 10 c. c. of alcohol, and 25 c. c, 
each of ethyl and petroleum ethers. Shake thoroughly after the 
addition of the ammonia ; one-half minute after the addition of 
the alcohol, and 20 seconds after the addition of each of tlie two 
ethers. Centrifuge 30 turns, taking one-half minute. 

For the second extraction, add neither water nor ammonia. 
Add 5 c. c. of alcohol, 25 c. c. each of ethyl and petroleum ether, 
and shake 20 seconds after the addition of each reagent. 

Centrifuge 30 turns, taking one-half minute. 

If necessary to raise the dividing line, add the necessary dis- 
tilled water just before pouring off the ether solution in the sec- 
ond extraction. After pouring off, heat the dish with the fat in 
the vacuum oven at 135" C. for five minutes with not less than 20 
inches of vacuum. 

Cool in the cooling desiccator to room temperature for seven 
minutes. 

Weigh rapidly. Record results, and calculate the percentage 
of fat. 

HOW TO TEST MALTED MILK, MILK CHOCOLATE, COCOA, 
CHEESE AND BUTTER EOR FAT. 

Follow the method of sampling recommended under each of 
these products in turn under Cha*pter VI. To weigh the samples in 
all cases, use either the butter boat or weigh directly into the ex- 
traction flask suspended from the balance arm. 

In the case of malted milk, chocolate and cocoa, use .5 gram 
sample. In the case of cheese and butter, use 1.0 gram sample. 

For the first extraction, add 8 c .c. of hot water, 1.5 c. e. of 
ammonia (3 c. c. in case of cheese), 10 c. c. of alcohol, and 25 e. c. 
of each ethyl and petroleum ethers. Shake thoroughly after the 
addition of the water and the ammonia; one-half minute after the 
addition of the alcohol, and 20 seconds after the addition of each 
of the two ethers. 

Centrifuge 30 turns, taking one-half minute. 



Milk PowdUr TiiST 111 

For the second extraction, add neither wator nor ammonia. 
Add 5 c. c. of alcohol, 25 c. c. each of ethyl and petroleum ether 
and shake 20 seconds after the addition of each reagent. 

Centrifuge 30 turns, taking one-half minute. 

If necessary to raise the dividing line, add the necessary dis- 
tilled water just before pouring off the ether solution in the sec- 
ond extraction. 

After evaporating off the ether, heat the dish with the fat in 
the vacuum oven at 135° C. for five minutes with not less than 20 
inches of vacuum. Cool in the cooling desiccator for seven 
minutes. 

Weigh rapidly. Record results and calculate the percentage 
of fat. 

HOW TO TEST SKIM-MILK POWDER, BUTTERMILK POWDER, 
AND WHOLE MILK POWDER FOR FAT. 

Follow the method of sampling recommended under these 
products in Chapter VI. To weigh the sample, use either the but- 
ter boat or weigh directly into the extraction flask suspended 
from the balance arm. Use about 1 gram sample. 

For the first extraction, add 8.5 c. c. of hot water, 1.5 c. c. 
of ammonia (3 c. c. in case of buttermilk), 10 c. c. of alcohol, and 
25 c. c. each of ethyl and petroleum ether. Shake thoroughly 
after adding water, again after adding ammonia, one-half minute 
after the addition of the alcohol, and 20 seconds after the addition 
of each of the two ethers. 

Centrifuge 30 turns, taking one-half minute. 

For the second extraction, add neither water nor ammonia. 
Add 5 c. c. of alcohol, and shake for 20 seconds. In the case of 
skim-milk powder, and buttermilk powder, add 15 c. c. each of 
ethyl and petroleum ether. In the case of whole milk powder 
add 25 c. c. each of ethyl and petroleum ether. 

Centrifuge 30 turns, taking one-half minute. 

If necessary to raise the dividing line, add the necessary dis- 
tilled water just before pouring off the ether solution, in the sec- 
ond extraction. 

After evaporating off the ether, heat the dish with the fat in 
the vacuum oven for five minutes with not less than 20 inches of 



112 A^IojoNNiER Fat Test 

vacuum. Cool in the cooling desiccator at room temperature for 
seven minutes. 

Weigh rapidly. Eecord results and calculate the percentage 
of fat. 

ORDER OF OPERATIONS IN TESTING EVAPORATED MILK 

FOR BUTTERFAT AND TOTAL SOLIDS WITH THE 

MOJONNIER TESTER. 

In the following outline, the procedure described is that used 
in the case of evaporated milk. The procedure used in the case of 
other products is much the same, but as mentioned both in Chap- 
ter VI and elsewhere in this chapter, differences may occur in the 
methods of sampling the products ; of weighing the samples ; the 
size of the samples to use ; the quantity of water- or other reagent 
to add; the method of shaking, and the method of centrifuging. 
The outline presumes that only one operator is doing the work. 
When speed is required, a helper to the operator can materially 
shorten the time required. In that case, the order of operations 
will need to be slightly modified. 

1. Place the respective dishes in the vacuum ovens and keep 
them therein for at least five minutes, while the ovens are heated, 
with the vacuum on. 

2. Transfer the respective dishes to the cooling desiccators ; 
turn on the pump, and set the bell for five minutes for solids, and 
seven minutes for fat. 

3. Weigh the solids dish first, being careful to put the cover 
upon the dish, and record the weight and the number, upon the 
laboratory report. Put the dish back into the cooling desiccator. 

4. Weigh the fat dish without the cover. Record the weight 
and the number upon the laboratory report, and put the fat dish 
into the cooling oven. 

5. Fill one 5 gram and one 1 gram pipette with milk, and 
place them upon the weighing cross, or weighing rack, or pref- 
erably, weigh the solids sample directly into the solids dish. 

6. Weigh the above and record the weight upon the labora- 
tory report upon the line entitled ''pipettes plus sample." 

7. Transfer the milk in the 5 grams pipette to the extraction 
flask, and return the empty pipette to the weighing cross, or to 
the weighing rack. 



Order of Operations 113 

8. Weigh again, and record the weight in the fat column upon 
the line entitled "pipettes." 

9. Also record the above weight in the solids column of the 
laboratory report, upon the line entitled "dish or pipettes plus 
sample." This operation may be omitted if the solids sample 
is weighed directly into the solids dish. 

10. Transfer the milk from the one gram pipette to the 
weighed solids dish, and return the pipette to the weighing cross, 
or to the weighing rack, or preferably, obtain the weight of the 
solids sample by weighing it directly into the solids dish. 

11. Place the weighing cross or the weighing rack upon the 
balance ; weigh, and record the weight upon the line entitled ' ' dish 
or pipette." This operation may be omitted if the solids sample 
is weighed directly into the solids dish. 

12. Add sufficient distilled water to the milk in the dish to 
make a total volume of 2 c. c. of liquid. Mix and distribute even- 
ly, and place the dish upon the solids hot plate. 

13. When evaporation has taken place, transfer the dish to 
the solids oven. 

14. Turn on the vacuum, and set the bell for ten minutes. 

15. At this point take the extraction flasks with the milk in 
the same, and make the first extraction. Centrifuge, and pour 
the ether into the fat dish. 

16. Make the second extraction, same as under 15. 

17. During the above period, the solids bell will ring, and the 
solids dish should be transferred to the cooling desiccator, and the 
bell set for five minutes. 

18. As soon as the ether has evaporated, place the dish in the 
fat oven ; turn on the vacuum, and set the bell for five minutes. 

19. When the bell for the solids side rings, weigh the dish, 
and record the weight. 

20. When the test bell for the fat side rings, transfer the 
dish to the cooling desiccator, and set the bell again for seven 
minutes. 

21. Complete the subtractions upon the laboratory report. 

22. Weigh the fat dish ; turn off the motor, and finish the 
calculations. 



114 MojoNNiHR Fat Test 

23, From the tests obtained, determine what material to add 
to standardize the batch. 

LIST OF PRECAUTIONS TO OBSERVE IN MAKING FAT TESTS 
UPON THE MOJONNIER TESTER. 

(1.) Before the reagents are put into the cans, the cans should 
be throughly cleansed by washing all parts, first with warm wa- 
ter, then with alcohol and finally with ether. Every third or 
fourth time that the cans are filled, empty out the last portion of 
the reagents, and use the same for cleaning purposes, unless tests 
prove the same to be of proper quality. 

(2.) The bottom of all dishes should be kept as flat as possi- 
ble. Any bulging should be worked out by resting the dishes 
upon the marble plate, in front of the balance, and rubbing the 
entire surface with the thumbs. The operator should observe 
this every time that the dishes are cleaned. This is very impor- 
tant. 

(3.) The calcium chloride in the cooling desiccators should be 
changed every three or four weeks. The same calcium chloride 
may be used over and over, by drying the moist calcium chloride 
in the tin dishes by placing the same upon the hot plate held at 
135'^ C. for at least five hours. However, the better method is to 
use a fresh supply, as soon as the supply in the desiccators be- 
comes saturated. 

(4.) The bottles should be whirled in the centrifuge until the 
ether extraction is perfectly clear. About 30 turns in half a min- 
ute is recommended. For sweetened condensed milk this time 
must be doubled. 

(5.) Be sure to keep the extraction flasks perfectly clean. 
Wash often with sulphuric acid and washing powder, if neces- 
sary. If particles cling to the sides, put in small shot, washing 
powder and hot water, and shake thoroughly. 

(6.) Keep the temperature regulated as near to standard 
temperature as possible. 

(7.) Never pour off the ether solution into a hot dish. Re- 
move the dish from the plate before the second extraction is run 
into the dish. 



Precautions 115 

(8.) Be careful to pour off the ether into the dishes slowly at 
first, and gradually increase the stream. 

(9.) In using the weighing pipettes, make sure that the neck 
of the flask is free from water when the pipette is inserted. 

(10.) Always use clean and dried pipettes. 



POSSIBLE CAUSES EOR HIGH FAT TESTS. 

If the results upon fat are higli as compared with the check 
results, the cause may be one or more of the following : 

(1.) Not keeping the bottom of the dishes flat. 

(2.) Improper shaking and centrifuging shoAvn by non-fatty 
residue in the dish. 

(3.) Impure reagents. (If in doubt, run test upon reagents 
substituting water for milk.) 

(4.) Temperature in fat oven too low. 

(5.) Dirt has gotten into the dish after the ether was poured 
into it. 

(6.) Improper reading or posting of weights. Weights have 
lost weight from use. 

(7.) Weighing the dish containing the fat at a lower tem- 
perature than prevailed when the dish was weighed empt.y. 



POSSIBLE CAUSES FOR LOW FAT TESTS. 

If the results on fat are Ioav as compared with check results, 
the cause may be one or more of the following : 

(1.) Leaky corks. Use best corks obtainable. 

(2.) Insufficient shaking. 

(3.) Adding too much water, or too little alcohol. 

(4.) Having dividing line too low, so that too much ether is 
left behind. If such is the case, add more water to bring the line 
to the proper height, before pouring off, or make a third extrac- 
tion. 



116 



MojonniEr Fat Test 



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Summary of Operations 



117 



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118 



MojoNNiER Fat Test 



METHODS FOR MAKING 

TOTAL SOLIDS OR MOISTURE 

TESTS 

Summary of Operations — Weigh 

directly into dish upon balance 




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PRliCAUTlONS 119 

(5.) Too high temperature in the vacuum oven. 

(6.) Insufficient water circulating through the cooling desic- 
cator. The water tank must be kept filled, and the circulating 
pump must be kept in good working order. 

(7.) Improper reading or posting of weights. 

(8.) Spattering of the fat in the oven due to transferring the 
dish to the oven before the ether solution had all evaporated, or 
if too high heat is carried in the vacuum oven. 

(9.) Weighing the dish at a higher temperature than pre- 
vailed when the dish was weighed empty. 

The following summary contains all the essential facts neces- 
sary for making both fat tests and total solids tests when using 
the Mojonnier Tester. This is arranged so the operator can tell 
at a glance just how to proceed when testing any given dairy 
product. 

For the convenience of the operator the table gives informa- 
tion regarding total solids tests which are covered in Chapter VIII, 
to which the reader is referred. 




CHAPTER VIII 

DIRECTIONS FOR MAKING TOTAL SOLIDS 

TESTS USING THE MOJONNIER 

MILK TESTER 

OUTLINE OF METHOD. 

The method for making total solids tests taking fresh milk as 
a typical example is in brief as follows : 

"Weigh about 2 grams of milk in the flat bottomed three inch 
diameter by one inch high aluminum dish, as illustrated under 
Fig. 54. Spread the milk in a thin film over the 
entire bottom of the dish. Place the dish in direct 
contact with the outside hot plate, having a tempera- 
ture of as near 180° C. as possible. Hold the dish 
upon the plate until the first trace of brown begins to 
appear. Now transfer the dish to the vacuum oven having a tem- 
perature of 100° C. Keep the dish in the oven for 10 minutes 
under a vacuum of not less than 20 inches. Transfer to the cool- 
ing desiccator, and hold it there for five minutes, with the water 
circulating pump operating continuously. "Weigh rapidly. Record 
the Aveights and calculate the percentage of total solids. 

Such modifications of the above method, as may be necessary 
in the case of various dairy products will be discussed further in 
this chapter. 

The successive steps involved in the entire method will now be 
discussed in careful detail. 

HOW TO WEIGH THE SAMPLES FOR THE SOLIDS TEST. 

The samples for the solids test can be weighed by means of the 
weighing cross, or the weighing pipette, as described under Chap- 
ter VII. In many cases it is best to weigh the samples directly 
into the solids dish, as illustrated under Fig. 55 on next page. The 
method of weighing that has been found by experience to give 
the best results, is recommended under each separate product. 

[120] 



Weighing the Sample 



121 




Fig-. 55. Welgrhingf the Solids Sample, 



WEIGHT OF SAMPLE TO TAKE FOR SOLIDS TEST. 

The weight of sample required varies from .25 gram in the case 
of sweetened condensed milk, to 2.00 grams in the ease of whole 
milk. It is very important to adhere as closely as possible to the 
size of sample recommended in the case of each separate product. 
The use of too large a sample will very likely cause high results. 
Too small a sample may introduce inaccuracies, and may cause 
either too high or too low results. 

HOW TO HANDLE THE DISHES AFTER THE SAMPLES HAVE 
BEEN WEIGHED IN THE SAME. 

The dishes with the samples after weighing, if not convenient 
to treat immediately upon the outside hot plate, should be placed 
either upon the marble plate which supports the balance, or they 
should be transferred to the cooling desiccator. In no case should 
they be kept upon the outside hot plate support, as that causes 
evaporation, and makes it subsequently difficult to mix properly 
with water. Water should be added to the samples, where neces- 
sary, as soon as possible after weighing, and the test carried 
through without stopping between the various operations. 

HOW TO ADD WATER TO THE SAMPLES IN THE SOLIDS DISH. 

When necessary to add water, always use the best distilled wa- 
ter. It is well to run a blank upon the water to determine if it is 
free from solid matter. Eeject any water that may contain any 
solid matter. Add sufficient water to make up a total volume that 



122 MojoNNiER ToTAi. Solids Tkst 

should not exceed 2 c, c, in the ease of the great majority of prod- 
ucts. Mix the sample with the water in the dish, so that the con- 
tents will be distributed uniformly over the bottom of the dish. 
In the case of several of the dairy products, this important opera- 
tion requires considerable skill and care. The necessary precau- 
tions will be found in the paragraphs describing the method of 
testing the various products. 

HOW TO TREAT THE SAMPLE UPON THE OUTSIDE SOLIDS 

HOT PLATE. 

It is very important to have the outside hot plate as near 
180° C. as possible. If a temperature of more than 180° C. is used, 
there is great danger of the sample spattering out of the dish. If 
a temperature of less than 180" C. is used, the operation will be re- 
tarded, and the substance dries in the form of a smooth crust from 
which it is difficult to remove the last remaining traces of water. 
Heat the sample in the dish until it just begins to turn brown. 
This is one of the most important steps in 
the entire operation, and unless properly 
watched an error may be introduced at this 
point. Insufficient heating may give high 
results, and over-heating may give low re- 
sults. Use the dish contact maker illustrated 
under Fig. 56, to press the bottom of the 
dish upon the hot plate. The dish should be 
so manipulated that vigorous boiling takes 
place upon tlie entire surface of the bottom 

Pigr. 56. Disli Contact |' ^i, i-^i. 
Maker. Used to Press the ^'^ ^'^ ai^ii. 
Dish Against the Hot 
Plate. 

TEMPERATURE AND VACUUM TO MAINTAIN IN THE SOLIDS 

OVEN. 

Keep the solids oven at a temperature as near 100° C. as pos- 
.sible. This applies to all products to be tested. Also see that 
there are at least 20 inches of vacuum upon the vacuum oven. If 
the Tester is properly operated, it should be possible to maintain 
25 inches of vacuum at all times. 

If for any reason, such for example as breakdown of the motor, 
it should be impossible to operate the power unit, the test can be 
completed in one and one-half liours without vacuum. If a 




Treatment of Souds Dish 



123 



vacuum of less than 20 inches only is obtainable, the time of 
holding the sample in the oven should be proportionately in- 
creased. As a general rule, the recommendation is as foUoAVs, in 
the case of products where the standard is 10 minutes : 



A'acuuin upon solids oven in 


How lono to k 


eep dishes in oven 


inches. 


under corres 


londing vacuum. - 


20 to 25 


10 minutes 


15 to 20 


20 


" 


10 to 15 


30 


" 


5 to 10 


40 


" 


no vacuum 


90 


*' 



HOW LONG TO RETAIN THE DISH IN THE SOLIDS OVEN. 

This varies with the product to be tested. Tlie minimum time is 
10 minutes, and in the case of sweetened condensed milk, in order 
to get absolute results, it is best to dry the samples one and one- 
half hours. 

HOW TO COOL THE SOLIDS DISH. 

Promptly transfer the dish from the oven to the cooling desic- 
cator, and keep it therein for five minutes, with the water circulat- 
ing daring this time. 

HOW TO WEIGH THE SOLIDS DISH. 

Always weigh the solids dish with the dish cover upon the dish. 
Make the weighings as rapidly as possible, as otherwise the sam- 
ple is quite likely to absorb moisture from the atmosphere. As in 
the case of the fat tests, a systematic method should be adopted 
for recording all data pertaining to the solids tests. A satisfac- 
tory blank report is illustrated under Fig, 53, Chapter VII, 

HOW TO CALCULATE THE PERCENTAGE OF TOTAL SOLIDS. 

Divide the weight of the total solids by the weight of the sam- 
ple taken, and multiply the result by 100, or move the decimal 
point two places to the right, which will give the percentage of to- 
tal solids in the sample. Example. Weight of solids found equals 
.2426 gram. Weight of sample taken equals 2.0216 grams. 
,2426 -^ 2.0216 = .1200 

.1200 X 100 = 12.00, or the per cent of total solids in 

the sample. 



124 MojoNNiER Total Solids Test 

HOW TO TEST FRESH MILK, SKIM-MILK, WHEY AND BUTTER- 
MILK FOR TOTAL SOLIDS. 

Follow the directions of sampling given in Chapter VI. To 
weigh the sample, use either the weighing cross, or the weighing 
pipette, using the 2 grams pipettes, or weigh the sample directly 
into the dish upon the balance pan. Use about 2 grams sample. 
Add no water. Spread the milk in a thin film over the entire bot- 
tom of the dish. Now place the dish in direct contact, upon the 
outside hot plate, which should have a temperature of 180'^ C, 
and heat the dish until the first traces of brown begin to appear 
in the residue. Transfer the dish to the vacuum oven at a temper- 
ature of 100° C. Keep in the vacuum oven for 10 minutes under 
not less than 20 inches of vacuum. Transfer to the cooling desic- 
cator, and hold it there for 5 minutes with the water circulating, 
pump operating continuously. "Weigh rapidly. Record weights, 
and calculate the percentage of total solids. 

HOW TO TEST EVAPORATED MILK AND ALL UNSWEETENED 

CONDENSED MILKS, INCLUDING CONDENSED BUTTERMILK 

FOR TOTAL SOLIDS. 

Follow the directions of sampling given in Chapter VI. To 
weigh the sample, use either the weighing cross, or the weighing 
pipettes, using the one gram pipettes, or weigh the sample directly 
into the dish upon the balance pan. Use one gram sample in all 
eases, except in the cases of extra heavy superheated plain bulk 
condensed milk and condensed buttermilk, in which cases .50 
gram sample should be taken. Add one c. c. of water to the 
sample in the dish in all cases, excepting in those of extra heavy 
superheated plain bulk condensed milk and condensed buttermilk, 
in which cases 2 c. c. of water should be added. Mix the milk and 
added water and spread in a thin film over the entire bottom of 
the dish. Now place the dish in direct contact upon the outside 
hot plate at a temperature of 180° C, and heat the dish until the 
first traces of brown begin to appear in the residue. Transfer the 
dish to the vacuum oven at a temperature of 100° C. Keep in the 
vacuum oven for 10 minutes under not less than 20 inches of vacu- 
um. Transfer to the cooling desiccator, and hold it there for five 
minutes with the water circulating pump operating continuously. 



Swe;e;te;ne;d Condensed Milk 125 

Weigh rapidly. Eecord weights, and calculate the percentage of 
total solids. 

HOW TO TEST SWEETENED CONDENSED MILK FOR TOTAL 

SOLIDS. 

Follow the directions of sampling given in Chapter VI. To 
weigh the sample use either the weighing cross or the weighing 
pipette, taking one gram pipette, or weigh the sample directly into 
the dish upon the balance pan. It is usually most convenient to 
use the same pipette that was used for weighing out the sample 
for the fat test. When this is done, it becomes unnecessary to 
use an additional pipette for handling the solids sample. Use 
about .25 gram sample. This amounts to about four to five small 
drops. These drops should be placed in different parts of the dish 
so that the milk can be more readily dissolved by the water which 
is to be added later. Add 2 c. c. of hot water. Sweetened con- 
densed milk is comparatively slow in dissolving. It is very im- 
portant to make a good mixture of the milk with the water, and to 
spread the milk in a thin film over the entire bottom of the dish. 
When this is done, the dish should be placed in direct contact with 
the hot plate, having a temperature of ISO'^ C. Heat the dish un- 
til the first traces of brown begin to appear in the residue. Trans- 
fer the dish to the vacuum oven at a temperature of 100° C. Keep 
in the vacuum oven for 20 minutes under not less than 20 inches of 
vacuum. This method, however, does not effect complete drying, 
and it is necessary to deduct .30 per cent from the total solids ob- 
tained. For example : If the total solids are found to be 73.86 
per cent when the sample was dried for 20 minutes, the .30 should 
be deducted which will give a net content of 73.56 per cent total 
solids. The results obtained with this method are almost identical 
with the results obtained when the sample is kept in the vacuum 
. oven for 90 minutes under not less than 20 inches of vacuum, and 
without making any deductions from the results obtained by dry- 
ing for 90 minutes. This method is recommended particularly for 
factory control work where the element of time is so important, 
while the second method is recommended where the element of 
time is of no consequence. In either method, transfer the dishes 
to the cooling desiccator at the end of the drying period, and hold 
it in the desiccator for five minutes with the water pump operat- 



126 MojoNNiER Total Solids Tkst 

ing continuously. Weigh rapidly. Eecord weights and calculate 
the percentage of total solids. On account of the small sample 
taken, and the general difficulties in the way of sampling and test- 
ing sweetened condensed milk, every possible precaution must be 
exercised in the testing of this product. 

HOW TO TEST ICE CREAM MIX FOR TOTAL SOLIDS. 

Follow the directions of sampling given in Chapter VI. To 
weigh the sample use either the weighing cross or the weighing 
pipette, or weigh the sample directly into the dish upon the bal- 
ance pan. In any case, use about one gram sample. Add 1 c. c. 
of water. Spread the ice cream mix with the added water in a 
thin film over the entire bottom of the dish. Now place the dish 
in direct contact upon the outside hot plate having a tempera- 
ture of 180" C, and heat the dish until the first traces of brown 
begin to appear in the residue. Transfer the dish to the vacuum 
oven at a temperature of 100'^ C. Keep in the vacuum oven for 
10 minutes under not less than 20 inches of vacuum. Transfer to 
the cooling desiccator, and hold it there for five minutes with the 
water circulating pump operating continuously. Weigh rapidly. 
Record weights, and calculate the percentage of total solids. 

HOW TO TEST CREAM FOR TOTAL SOLIDS. 

Follow the directions of sampling given in Chapter VI. To 
weigh the sample, use either the weighing cross, or the weighing 
pipette, using the two grams pipette. It is frequently necessary 
to weigh the sample directly into the dish upon the balance pan, 
or to weigh it in the butter boat. The method of weighing se- 
lected is to be governed by the mechanical condition of the sample 
to be tested. In the case of cream testing less than 25 per cent of 
butterfat, use one gram sample. In the case of cream testing 
more than 25 per cent of butterfat, use .50 gram sample. In the. 
case of cream testing less than 25 per cent of fat, add 1 c. c. of 
water to the sample in the dish. In the case of cream testing 
more than 25 per cent of fat, add 1.5 c. c. of water. Spread the 
milk with the added water in a thin film over the entire bottom 
of the dish. Now place the dish in direct contact upon the outside 
hot plate having a temperature of 180° C. and heat the dish until 
the first traces of brown begin to appear in tlie residue. Place 



jMiscellankous Products 127 

in the vacimni oven for 10 minutes under not less than 20 
inches of vacuum. Transfer to the cooling desiccator, and hold it 
there for five minutes with the water circulating pump operating 
continuously. Weigh rapidly. Record weights, and calculate the 
percentage of total solids. 

HOW TO TEST MALTED MILK, MILK CHOCOLATE AND COCOA 
FOR TOTAL SOLIDS. 

Follow the directions of sampling given in Chapter VI. Weigh 
the sample directly into the dish upon the balance pan. Use 
about .30 gram sample. Add 2 c. c. of hot water. Spread the 
sample with the added water in a thin film over the entire bottom 
of the dish. Now place the dish in direct contact upon the out- 
side hot plate having a temperature of 180° C. and heat the dish 
until the first traces of brown begin to appear in the residue. 
Transfer the dish to the vacuum oven having a temperature of 
100° C. Keep in the vacuum oven for 20 minutes under not less 
than 20 inches of vacuum. Transfer to the cooling desiccator, 
and hold it there for five minutes with the water circulating pump 
operating continuously. Weigh rapidly. Record weights, and 
calculate the percentage of total solids. 

HOW TO TEST CHEESE FOR TOTAL SOLIDS. 

Follow the directions of sampling given in Chapter VI. Weigh 
the sample directly into the dish upon the balance pan. Weigh 
with the dish and the sample, a blunt pointed glass rod that can 
be used to break up any possible lumps of cheese that may later 
appear in the dish. Use about .50 gram sample. Add 1.5 c. c. of 
hot water. Spread the cheese with the added water in a thin 
film over the entire bottom of the dish. Use the glass rod to break 
up any lumps. Now place the dish in direct contact upon the 
outside hot plate having a temperature of as nearly 180° C. as 
possible, and heat the dish until the first traces of brown begin to 
appear in the residue. Transfer the dish to the vacuum oven 
having a temperature of 100° C. Keep in the vacuum oven for 
20 minutes under not less than 20 inches of vacuum. Transfer in 
the cooling desiccator, and hold it there for five minutes with the 
water circulating pump operating continuously. Weigh rapidly. 
Record results, and calculate the percentage of total solids. 



128 MojoNNiER Total Solids Test 

HOW TO TEST BUTTER FOR TOTAL SOLIDS. 

Follow the method of sampling recommended in Chapter VI. 
Weigh the sample directly into the dish upon the balance pan. 
Use about one gram sample. Add no water. Heat the dish in di- 
rect contact upon the outside hot plate, having a temperature of 
180° C. until spattering ceases, or until the first traces of brown 
begin to appear in the residue. Transfer the dish to the vacuum 
oven having a temperature of 100° C. Keep in the vacuum oven 
for 10 minutes under not less than 20 inches of vacuum. Transfer 
to the cooling desiccator and hold it there for 5 minutes with the 
water circulating pump operating continuously. Weigh rapidly. 
Kecord results and calculate the percentage of total solids. 

HOW TO TEST SKIM-MILK, WHOLE MILK POWDER AND 
BUTTERMILK POWDER FOR TOTAL SOLIDS. 

Follow the directions of sampling as given in Chapter VI. 
Weigh the sample directly into the dish upon the balance pan. 
Use about .3 gram sample. Add 2 c. c. of hot water and spread 
the sample with the water in a thin film over the entire bottom 
of the dish. Now place the dish in direct contact upon the out- 
side hot plate having a temperature of 180° C, and heat the dish 
until the first trace of brown begins to appear in the residue. 
Transfer the dish to the vacuum oven having a temperature of 
100° C. Keep in the vacuum oven for 10 minutes under not less 
than 20 inches of vacuum. ^ Transfer to the cooling desiccator, and 
hold it there for 5 minutes with the water circulating pump oper- 
ating continuously. Weigh rapidly, record results, and calculate 
the percentage of total solids. 

POSSIBLE CAUSES FOR TOO HIGH SOLIDS TESTS. 

(1). Bottoms of dishes were not kept flat. 

(2). Evaporation upon the outside solids hot plate had not 
been carried far enough, or it had been done at an improper tem- 
perature. Do not remove dish until all visible moisture is off, or 
until the first trace of brown coloration appears. 

(3). Improper reading or recording of weights. Weights 
have lost weight from use. 

(4). Dirt had fallen into dish after sample had been weighed 
into it. 



Causes of Inaccurate Tests 129 

(5). Temperature in the vacuum oven was too low. 

(6). Vacuum was not up to standard. 

(7). Too large a sample was taken, rendering it impossible 
to remove all the water under the conditions recommended. 

(8). "Weighing the dish with the solids in the same at a lower 
temperature than prevailed when the dish was weighed empty. 

POSSIBLE CAUSES FOR TOO LOW TOTAL SOLIDS TESTS. 

(1). Sample was browned too much upon the outside hot 
plate, due either to too long exposure or to the use of too high 
temperature upon the hot plate. 

(2). Temperature in the vacuum oven was above 100° C. 

(3). Milk spattered from the dish. This will not happen if 
the temperature is kept at 180° C. 

(4). Improper reading or recording of the weights. 

(5). Water was not running through the cooler. 

(6). "Weighing the dish with the solids in the same at a higher 
Temperature than prevailed when the dish was weighed empty. 

SUMMARY OF METHODS RECOMMENDED FOR TESTING ALL 
DAIRY PRODUCTS FOR TOTAL SOLIDS. 

For this summary the reader is referred to Table 21 at the 
close of Chapter VII, This gives in a condensed form all the im- 
portant information required, covering the making of total solids 
tests when using the Mojonnier Tester. 



CHAPTER IX 

GENERAL INFORMATION REGARDING THE 

STANDARDIZING OF DAIRY 

PRODUCTS 

STANDARDIZATION DEFINED. 

Standardizing is defined as "comparing with a standard, or 
rendering standard." As applied to the dairy industry, it has a 
very broad application, inasmuch as it is used with reference to 
methods of plant operation ; the processing of various dairy prod- 
ucts and the physical, chemical and bacteriological limits permis- 
sible under a wide variety of products and conditions. 

In this book the emphasis is placed upon the standardization 
of the chemical constituents with especial reference to the fat and 
the solids not fat content of dairy products. These are the most 
important constituents of all dairy products both from a chem- 
ical and a commercial standpoint, inasmuch as they affect both 
the quality and the cost of the finished products. 

Consideration will also be given to the standardization of 
products added in the manufacture of certain dairy products, 
such as the addition of sugar when manufacturing sweetened con- 
densed milk, or of sugar and gelatin when making ice cream. 

Standardization is usually understood to mean either the rais- 
ing or the lowering of either or of both the fat or solids not fat 
content of all dairy products to a certain fixed standard. 

In practice it is possible to standardize either the fat or the 
solids not fat alone, or the two constituents together in the same 
product. Where the two constituents are standardized, the same 
will be present in the finished product in a constant ratio, one to 
the other. Methods will be given for standardizing various dairy 
products under the two conditions named. 

[130] 



Preliminary Operations 131 

SUCCESSIVE STEPS INVOLVED IN STANDARDIZING. 

(a). When standardizing for one constituent only. 

The steps involved when standardizing a single constituent 
are as follows : 

(1). Obtaining a representative composite sample of the en- 
tire lot of product which makes up the batch, and likewise of the 
skim-milk or cream which might be used in standardizing. 

(2). Testing all of the above products for fat or total solids, 
depending upon the constituent to be standardized. Where ac- 
curate results are desired, these tests should be made upon the 
Mojonnier Tester. 

(3). Calculating the weight of each product to be used, by 
methods which will follow, and mixing the products together in 
the proper proportions. 

(b). When standardizing for both fat and total solids. 

The steps involved in standardizing dairy products for both 
fat and S. N. F. are as follows : 

(1). Obtaining a representative composite sample of the en- 
tire lot of milk which goes to make up the batch, and likewise of 
skim-milk and the cream which might be used in standard- 
izing. 

(2). Testing of all of the above products involved, for both 
fat and S. N. F. or T. S. by means of the Mojonnier Tester, ex- 
cepting that in the case of cream the S. N. F. can be obtained by 
referring to Table 22 found in this chapter, instead of by actual 
test. 

(3). Calculating the weight of each product to be used by 
methods which will follow, in order to bring the fat and S. N. F. 
to the same ratio that they are to have in the standardized prod- 
uct that it is desired to make. If the resulting product should be 
over the desired standard, the necessary water is to be added to 
bring it back to the required test. 

METHOD OF OBTAINING COMPOSITE SAMPLES. 

The reader is referred to Chapter VI for methods recommended 
for obtaining representative samples of all the various dairy prod- 
ucts. It must be kept constantly in mind that accuracy of final 
results is impossible unless the samples taken be representative 
of the entire batch. 



132 Standardization oi' Dairy Products 

METHOD OF GETTING WEIGHTS OF THE PRODUCTS. 

The man who does the standardizing should be sure that the 
pounds of whole milk, likewise the pounds of cream and skim-milk 
used as well as the pounds of all other products involved are cor- 
rectly reported, and properly checked. If this part of the work 
is not properly done, large errors may be introduced in the work. 
In many plants it is impossible to weigh all the products accu- 
rately. In such cases the pounds should be obtained by multi- 
plying the volume by the specific gravity or by means of a grad- 
uated indicator upon the basis of definite weights of the product 
placed in the tank under the same temperature as obtain in prac- 
tice. 

METHOD OF TESTING RECOMMENDED. 

Where accurate results are desired, the Mojonnier Tester 
should be used for making both fat and total solids tests. Only 
approximate results can be obtained if other methods are used 
for making these determinations. 

METHOD OF CALCULATION TO USE. 

In subsequent chapters methods of calculation are given, cov- 
ering the entire range of important dairy products, under a wide 
variety of conditions. The reader is referred to these chapters 
for all details. For the sake of clarity, solutions are given by 
formula, by rule and by example, using simple arithmetic only. 

THE USE OF TABLES IN SHORTENING CALCULATIONS. 

Much time in making the calculations can be saved by using 
tables, the following of which are especially recommended : 

(1.) Table showing the percentage of S. N. F. and percentage 
of total solids corresponding to any given percentage of fat in 
cream. 

(2.) Table showing percentage of S. N. F. in various dairy 
products corresponding to any given percentage of fat. Tables 
of this kind can be prepared to cover all different dairy products. 
To prepare such tables, it is necessary to know the final composi- 
tion of the product desired. Several tables of this nature will be 
found in subsequent chapters, and the reader will find the proper 
explanation for their use in connection therewith, 



Composition of Cream 133 

Table 22 gives the corresponding: percentage of fat, solids not 
fat and total solids in cream starting with a cream having a total 
solids content of 23.00 per cent and ending with a cream having a 
total solids content of 60 per cent. 

The values given were derived from the formula : 
F=: 1.102 X T. S. — 10.2 
F ^^ the percentage of fat 
T. S. = the percentage of total solids. 
The formula is based upon the assumption that on the average 
there are 100 parts of water for 10.2 parts of milk solids not fat. 
An example taking an actual test of cream for both fat and total 
solids using the Mojonnier Tester will serve to illustrate how the 
above formula is derived. The sample tested 45.20 per cent total 
solids and 39.61 per cent fat. 

100 — 45.20 = 54.80, per cent water in sample. 
45.20 — 39.61 = 5.59, per cent solids not fat in sample. 
To find parts or units of solids not fat for 100 parts of water, 
we have the ratio : 

54.80 : 100 = 5.59 : X 

X = 10.20, the parts of solids not fat contained in 100 parts 

of water in cream of the above test. 
In some cases the actual test as found by means of the Mojon- 
nier Tester may be either a little higher or a little lower than the 
values given in the table. Inasmuch as the total pounds of cream 
used in standardizing, as a rule are not large, an error as above 
mentioned would not appreciably afifect the final results. 



134 



Standardization oi^ Dairy Products 



TABLE 22. 

Per Cent S. N. F. and T. S. in Cream Corresponding to Any Given Percentage 

of Fat. 



Fat. 


S.N.F. 


T. S. 


Fat. 


S. N. F. 


T.S. 


Fat. 


S.N.F. 


T.S. 


15.15 


7.85 


23.00 


17.41 


7.64 


25.05 


19.66 


7.44 


27.10 


15.20 


7.85 


23.05 


17.46 


7.64 


25.10 


19.72 


7.43 


27.15 


15.25 


7.84 


23.10 


17.52 


7.63 


25.15 


19.77 


7.43 


27.20 


15.31 


7.84 


23.15 


17.57 


7.63 


25.20 


19.83 


7.42 


27.25 


15.37 


7.83 


23.20 


17.63 


7.62 


25.25 


19.88 


7.42 


27.30 


15.42 


7.83 


23.25 


17.68 


7.62 


25.30 


19.94 


7.41 


27.35 


15.48 


7.82 


23.30 


17.74 


7.61 


25.35 


19.99 


7.41 


27.40 


15.53 


7.82 


23.35 


17.79 


7.61 


25.40 


20.05 


7.40 


27.45 


15.59 


7.81 


23.40 


17.85 


7.60 


25.45 


20.11 


7.39 


27.50 


15.64 


7.81 


23.45 


17.90 


7.60 


25.50 


20.16 


7.39 


27.55 


15.70 


7.80 


23.50 


17.96 


7.59 


25.55 


20.22 


7.38 


27.60 


15.75 


7.80 


23.55 


18.01 


7.59 


25.60 


20.27 


7.38 


27.65 


15.81 


7.79 


23.60 


18.07 


7.58 


25.65 


20.32 


7.37 


27.70 


15.86 


7.79 


23.65 


18.12 


7.58 


25.70 


20.38 


7.37 


27.75 


15.92 


7.78 


23.70 


18.18 


7.57 


25.75 


20.44 


7.36 


27.80 


15.97 


7.78 


23.75 


18.23 


7.57 


25.80 


20.49 


7.36 


27.85 


16.03 


7.77 


23.80 


18.29 


7.56 


25.85 


20.55 


7.35 


27.90 


16.08 


7.77 


23.85 


18.34 


7.56 


25.90 


20.60 


7.35 


27.95 


16.14 


7.76 


23.90 


18.40 


7.55 


25.95 


20.68 


7.34 


28.00 


16.19 


7.76 


23.95 


18.45 


7.55 


26.00 


20.71 


7.34 


28.05 


16.25 


7.75 


24.00 


18.51 


7.54 


26.05 


20.77 


7.33 


28.10 


16.30 


7.75 


24.05 


18.56 


7.54 


26.10 


20.82 


7.33 


28.15 


16.36 


7.74 


24.10 


18.62 


7.53 


26.15 


20.88 


7.33 


28.20 


16.41 


7.74 


24.15 


18.67 


7.53 


26.20 


20.93 


7.32 


28.25 


16.47 


7.73 


24.20 


18.73 


7.52 


26.25 


20.99 


7.31 


28.30 


16.52 


7.73 


24.25 


18.78 


7.52 


26.30 


21.04 


7.31 


28.35 


16.58 


7.72 


24.30 


18.84 


7.51 


26.35 


21.10 


7.30 


28.40 


16.63 


7.72 


24.35 


18.89 


7.51 


26.40 


21.15 


7.30 


28.45 


16.69 


7.71 


24.40 


18.95 


7.50 


26.45 


21.21 


7.29 


28.50 


16.74 


7.71 


24.45 


19.00 


7.50 


26.50 


21.26 


7.29 


28.55 


18.80 


7.70 


24.50 


19.06 


7.49 


26.55 


21.32 


7.28 


28.60 


16.85 


7.70 


24.55 


19.11 


7.49 


26.60 


21.37 


7.28 


28.65 


16.91 


7.69 


24.60 


19.17 


7.48 


26.65 


21.43 


7.27 


28.70 


16.96 


7.69 


24.65 


19.22 


7.48 


26.70 


21.48 


7.27 


28.75 


17.02 


7.68 


24.70 


19.28 


7.47 


26.75 


21.54 


7.26 


28.80 


17.07 


7.68 


24.75 


19.33 


7.47 


26.80 


21.59 


7.26 


28.85 


17.13 


7.67 


24.80 


19.39 


7.46 


26.85 


21.65 


7.25 


28.90 


17.18 


7.67 


24.85 


19.44 


7.46 


29.90 


21.70 


8.25 


28.95 


17.24 


7.66 


24.90 


19.50 


7.45 


26.95 


21.76 


7.24 


29.00 


17.29 


7.66 


24.95 


19.55 


7.45 


27.00 


21.81 


7.24 


29.05 


17.35 


7.65 


25.00 


19.61 


7.44 


27.05 


21.87 


7.23 


29.10 



Composition of Crivam 

TABLE 22 (Continued). 



135 



Fat. 


S.N.F. 


T.S. 


Fat. 


S.N.F. 


T.S. 


Fat. 


S.N.F. 


T.S. 


21.92 


7.23 


29.15 


24.18 


7.02 


31.20 


26.44 


6.81 


33.25 


21.98 


7.22 


29.20 


24.24 


7.01 


31.25 


26.50 


6.80 


33.30 


22.03 


7.22 


29.25 


24.29 


7.01 


31.30 


26.55 


6.80 


33.35 


22.09 


7.21 


29.30 


24.35 


7.00 


31.35 


26.61 


6.79 


33.40 


22.14 


7.21 


29.35 


24.40 


7.00 


31.40 


26.66 


6.79 


33.45 


22.20 


7.20 


29.40 


24.46 


6.99 


31.45 


26.72 


6.78 


33.50 


22.25 


7.20 


29.45 


24.51 


6.99 


31.50 


26.77 


6.78 


33.55 


22.31 


7.19 


29.50 


24.57 


6.98 


31.55 


26.83 


6.77 


33.60 


22.36 


7.19 


29.55 


24.62 


6.98 


31.60 


26.88 


6.77 


33.65 


22.42 


7.18 


29.60 


24.68 


6.97 


31.65 


26.94 


6.76 


33.70 


22.47 


7.18 


29.65 


24.73 


6.97 


31.70 


26.98 


6.76 


33.75 


22.53 


7.17 


29.70 


24.79 


6.96 


31.75 


27.05 


6.75 


33.80 


22.58 


7.17 


29.75 


24.84 


6.96 


31.80 


27.10 


6.75 


33.85 


22.64 


7.16 


29.80 


24.90 


6.95 


31.85 


27.16 


6.74 


33.90 


22.69 


7.16 


29.85 


24.95 


6.95 


31.90 


27.21 


6.74 


33.95 


22.75 


7.15 


29.90 


25.01 


6.94 


31.95 


27.27 


6.73 


34.00 


22.80 


7.15 


29.95 


25.06 


6.94 


32.00 


27.32 


6.73 


34.05 


22.86 


7.14 


30.00 


25.12 


6.93 


32.05 


27.38 


6.72 


34.10 


22.91 


7.14 


30.05 


25.17 


6.93 


32.10 


27.43 


6.72 


34.15 


22.97 


7.13 


30.10 


25.23 


6.92 


32.15 


27.49 


6.71 


34.20 


23.03 


7.12 


30.15 


25.28 


6.92 


32.20 


27.54 


6.71 


34.25 


23.08 


7.12 


30.20 


25.34 


6.91 


32.25 


27.60 


6.70 


34.30 


23.14 


7.11 


30.25 


25.39 


6.91 


32.30 


27.65 


6.70 


34.35 


23.19 


7.11 


30.30 


25.45 


6.90 


32.35 


27.71 


6.69 


34.40 


23.25 


7.10 


30.35 


25.50 


6.90 


32.40 


27.76 


6.69 


34.45 


23.30 


7.10 


30.40 


25.56 


6.89 


32.45 


27.82 


6.68 


34.50 


23.36 


7.09 


30.45 


25.62 


6.88 


32.50 


27.87 


6.68 


34.55 


23.41 


7.09 


30.50 


25.67 


6.88 


32.55 


27.93 


6.67 


34.60 


23.47 


7.08 


30.55 


25.73 


6.87 


32.60 


27.98 


6.67 


34.65 


23.52 


7.08 


30.60 


25.78 


6.87 


32.65 


28.04 


6.66 


34.70 


23.58 


7.07 


30.65 


25.84 


6.86 


32.70 


28.09 


6.66 


34.75 


23.63 


7.07 


30.70 


25.89 


6.86 


32.75 


28.15 


6.65 


34.80 


23.69 


7.06 


30.75 


25.95 


6.86 


32.80 


28.20 


6.65 


34.85 


23.74 


7.06 


30.80 


26.00 


6.85 


32.85 


28.26 


6.64 


34.90 


23.80 


7.05 


30.85 


26.06 


6.84 


32.90 


28.31 


6.64 


34.95 


23.85 


7.05 


30.90 


26.11 


6.84 


32.95 


28.37 


6.63 


35.00 


23.91 


7.04 


30.95 


26.17 


6.83 


33.00 


28.43 


6.62 


35.05 


23.96 


7.04 


31.00 


26.22 


6.83 


33.05 


28.48 


6.62 


35.10 


24.02 


7.03 


31.05 


26.28 


6.82 


33.10 


28.54 


6.61 


35.15 


24.07 


7.03 


31.10 


26.33 


6.82 


33.15 


28.59 


6.61 


35.20 


24.13 


7.02 


31.15 


26.39 


6.81 


33.20 


28.65 


6.60 


35.25 



136 



Standardization of Dairy Products 
TABLE 22 (Continued). 



Fat. 


S.N.F. 


T.S. 


Fat. 


S.N.F. 


T.S. 


Fat. 


S.N.F. 


T.S. 


28.70 


6.60 


35.30 


30.96 


6.39 


37.35 


33.22 


6.18 


39.40 


28.76 


6.59 


35.35 


31.01 


6.39 


37.40 


33.27 


6.18 


39.45 


28.81 


6.59 


35.40 


31.07 


6.38 


37.45 


33.33 


6.17 


39.50 


28.87 


6.58 


35.45 


31.13 


6.37 


37.50 


33.38 


6.17 


39.55 


28.92 


6.58 


35.50 


31.18 


6.37 


37.55 


33.44 


6.16 


39.60 


28.98 


6.57 


35.55 


31.24 


6.36 


37.60 


33.49 


6.16 


39.65 


29.03 


6.57 


35.60 


31.29 


6.36 


37.65 


33.55 


6.15 


39.70 


29.09 


6.56 


35.65 


31.35 


6.35 


37.70 


33.60 


6.15 


39.75 


29.14 


6.56 


35.70 


31.40 


6.35 


37.75 


33.66 


6.14 


39.80 


29.20 


6.55 


35.75 


31.46 


6.34 


37.80 


33.71 


6.13 


39.85 


29.25 


6.55 


35.80 


31.51 


6.34 


37.85 


33.77 


6.13 


39.90 


29.31 


6.54 


35.85 


31.57 


6.33 


37.90 


33.82 


6.13 


39.95 


29.36 


6.54 


35.90 


31.62 


6.33 


37.95 


33.88 


6.12 


40.00 


29.42 


6.53 


35.95 


31.68 


6.32 


38.00 


33.94 


6.11 


40.05 


29.47 


6.53 


36.00 


31.73 


6.32 


38.05 


33.99 


6.11 


40.10 


29.53 


6.52 


36.05 


31.79 


6.31 


38.10 


34.05 


6.10 


40.15 


29.58 


6.52 


36.10 


31.84 


6.31 


38.15 


34.10 


6.10 


40.20 


29.64 


6.51 


36.15 


31.90 


6.30 


38.20 


34.16 


6.09 


40.25 


29.69 


6.51 


36.20 


31.95 


6.30 


38.25 


34.21 


6.09 


40.30 


29.75 


6.50 


36.25 


32.01 


6.29 


38.30 


34.27 


6.08 


40.35 


29.80 


6.50 


36.30 


32.06 


6.29 


38.35 


34.32 


6.08 


40.40 


29.86 


6.49 


36.35 


32.12 


6.28 


38.40 


34.38 


6.07 


40.45 


29.91 


6.49 


36.40 


32.17 


6.28 


38.45 


34.43 


6.07 


40.50 


29.97 


6.48 


36.45 


32.23 


6.27 


38.50 


34.49 


6.06 


40.55 


30.02 


6.48 


36.50 


32.28 


6.27 


38.55 


34.54 


6.06 


40.60 


30.08 


6.47 


36.55 


32.34 


6.26 


38.60 


34.60 


6.05 


40.65 


30.13 


6.47 


36.60 


32.39 


6.26 


38.65 


34.65 


6.05 


40.70 


30.19 


6.46 


36.65 


32.45 


6.25 


38.70 


34.71 


6.04 


40.75 


30.24 


6.46 


36.70 


32.50 


6.25 


38.75 


34.76 


6.04 


40.80 


30.30 


6.45 


36.75 


32.56 


6.24 


38.80 


34.82 


6.03 


40.85 


30.35 


6.45 


36.80 


32.61 


6.24 


38.85 


34.87 


6.03 


40.90 


30.41 


6.44 


36.85 


32.67 


6.23 


38.90 


34.93 


6.02 


40.95 


30.46 


6.44 


36.90 


32.72 


6.23 


38.95 


34.98 


6.02 


41.00 


30.52 


6.43 


36.95 


32.78 


6.22 


39.00 


35.04 


6.01 


41.05 


30.57 


6.43 


37.00 


32.83 


6.22 


39.05 


35.09 


6 01 


41.10 


30.63 


6.42 


37.05 


32.89 


6.21 


39.10 


35.15 


6.00 


41.15 


30.68 


6.42 


37.10 


32.94 


6.21 


39.15 


35.20 


6.00 


41.20 


30.74 


6.41 


37.15 


33.00 


6.20 


39.20 


35.26 


5.99 


41.25 


30.79 


6.41 


37.20 


33.05 


6.20 


39.25 


35.31 


5.99 


41.30 


30,85 


6.40 


37.25 


33.11 


6.19 


39.30 


35.37 


5.98 


41.35 


30.90 


6.40 


37.30 


33.16 


6.19 


39.35 


35.42 


5.98 


41.40 



Composition of Cream 
TABLE 22 (Continued). 



137 



Fat. 


S.N.F. 


T.S. 


Fat. 


S.N.F. 


T.a. 


Fat. 


S.N.F. 
5.55 


T.S. 


35.48 


5.97 


41.45 


37.74 


5.76 


43.50 


40.00 


45.55 


35.53 


5.97 


41.50 


37.79 


5.76 


43.55 


40.05 


5.55 


45.60 


35.59 


5.96 


41.55 


37.85 


5.75 


43.60 


40.11 


5.54 


45.65 


35.64 


5.96 


41.60 


37.90 


5.75 


43.65 


40.16 


5.54 


45.70 


35.70 


5.95 


41.65 


37.96 


5.74 


43.70 


40.22 


5.53 


45.75 


35.75 


5.95 


41.70 


38.01 


5.74 


43.75 


40.27 


5.53 


45.80 


35.81 


5.94 


41.75 


38.07 


5.73 


43.80 


40.33 


5.52 


45.85 


35.86 


5.94 


41.80 


38.12 


5.73 


43.85 


40.38 


5.52 


45.90 


35.92 


5.93 


41.85 


38.18 


5.72 


43.90 


40.44 


5.51 


45.95 


35.97 


5.93 


41.90 ■ 


38.23 


5.72 


43.95 


40.49 


5.51 


46.00 


36.03 


5.92 


41.95 


38.29 


5.71 


44.00 


40.55 


5.50 


46.05 


36.08 


5.92 


42.00 


38.34 


5 71 


44.05 


40.60 


5.50 


46.10 


36.14 


5.91 


42.05 


38.40 


5.70 


44.10 


40.66 


5.49 


46.15 


36.19 


5.91 


42.10 


38.45 


5.70 


44.15 


40.71 


5.49 


46.20 


36.25 


5.90 


42.15 


38.51 


5.69 


44.20 


40.77 


5.48 


46.25 


36.30 


5.90 


42.20 


38.56 


5.69 


44.25 


40.82 


5.48 


46.30 


36.36 


5.89 


42.25 


38.62 


5.68 


44.30 


40.88 


5.47 


46.35 


36.41 


5.89 


42.30 


38.67 


5 68 


44.35 


40.93 


5.47 


46.40 


36.47 


5.88 


42.35 


38.73 


5.67 


44.40 


40.99 


5.46 


46.45 


36.52 


5.88 


42.40 


■ 38.78 


5.67 


44.45 


41.04 


5.46 


46.50 


36.58 


5.87 


42.45 


38.84 


5.66 


44.50 


41.10 


5.45 


46.55 


36.64 


5.86 


42.50 


38.89 


5.66 


44.55 


41.15 


5.45 


46.60 


36.69 


5.86 


42.. 55 


38.95 


5.65 


44.60 


41.21 


5.44 


46.65 


36.75 


5.85 


42.60 


39.00 


5.65 


44.65 


41.26 


5.44 


46.70 


36.80 


5.85 


42.65 


39.06 


5.64 


44.70 


41. .32 


5.43 


46.75 


36.86 


5.84 


42.70 


39.11 


5.64 


44.75 


41.37 


5.43 


46.80 


36.91 


5.84 


42.75 


39.17 


5.63 


44.80 


41 .43 


5.42 


46.85 


36.97 


5.83 


42.80 


39.22 


5.63 


44.85 


41.48 


5.42 


46.90 


37.02 


5.83 


42.85 


39.28 


5.62 


44.90 


41. .54 


5.41 


46.95 


37.08 


5.82 


42.90 


39.33 


5.62 


44.95 


41.59 


5.41 


47.00 


37.13 


5.82 


42.95 


39.39 


5.61 


45.00 


41.65 


5.40 


47.05 


37.19 


5.81. 


43.00 


.39.45 


5.60 


45.05 


41.70 


5.40 


47.10 


37.24 


5.81 


43.05 


39.50 


5.60 


45.10 


41.76 


5.39 


47.15 


37.30 


5.80 


43.10 


39.56 


5.59 


45.15 


41.81 


5.39 


47.20 


37.35 


5.80 


43.15 


39.61 


5.59 


45.20 


41.87 


5.38 


47.25 


37.41 


5.79 


43.20 


39.67 


5.58 


45.25 


41.92 


5.38 


47.30 


37.46 


5.79 


43.25 


39.72 


5.58 


45.30 


41.98 


5.37 


47.35 


37.52 


5.78 


43.30 


39.78 


5.57 


45.35 


42.03 


5.37 


47.40 


37.57 


5.78 


43.35 


39.83 


5.57 


45.40 


42.09 


5.36 


47.45 


37.63 


5.77 


43.40 


39.89 


5.56 


45.45 


42.15 


5.35 


47.50 


37.68 


5.77 


43.45 


39.94 


5.56 


45.50 


42.20 


5.35 


47.55 



138 



Standardization of Dairy Produci's 
TABLE 22 (Continued). 



Fat. 


S.N.F. 


T.S. 


Fat. 


S.N.F. 


T.S. 


Fat. 


S.N.F. 


T.S. 


42.26 


5.34 


47.60 


44.51 


5.14 


49.65 


46.77 


4.93 


51.70 


42.31 


5.34 


47.65 


44.57 


5.13 


49.70 


46.83 


4.92 


51.75 


42.37 


5.33 


47.70 


44.62 


5.13 


49.75 


46.88 


4.92 


51.80 


42.42 


5.33 


47.75 


44.68 


5.12 


49.80 


46.94 


4.91 


51.85 


42.48 


5.32 


47.80 


44.73 


5.12 


49.85 


46.99 


4.91 


51.90 


42.53 


5.32 


47.85 


44.79 


5.11 


49.90 


47.05 


4.90 


51.95 


42.59 


5.31 


47.90 


44.84 


5.11 


49.95 


47.10 


4.90 


52.00 


42.64 


5.31 


47.95 


44.90 


5.10 


50.00 


47.16 


4.89 


52.05 


42.70 


5.30 


48.00 


44.96 


5.09 


50.05 


47.21 


4.89 


52.10 


42.75 


5.30 


48.05 


45.01 


5.09 


50.10 


47.27 


4.88 


52.15 


42.81 


5.29 


48.10 


45.07 


5.08 


50.15 


47.32 


4.88 


52.20 


42.86 


5.29 


48.15 


45.12 


5.08 


50.20 


47.38 


4.87 


52.25 


42.92 


5.28 


48.20 


45.18 


5.07 


50.25 


47.43 


4.87 


52.30 


42.97 


5.28 


45.25 


45.23 


5.07 


50.30 


47.49 


4.86 


52.35 


43.03 


5.27 


48.30 


45.29 


5.06 


50.35 


47.54 


4.86 


52.40 


43.08 


5.27 


48.35 


45.34 


5.06 


50.40 


47.60 


4.85 


52.45 


43.14 


5.26 


48.40 


45.40 


5.05 


50.45 


47.66 


4.84 


52.50 


43.19 


5.26 


48.45 


45.45 


5.05 


50.50 


47.71 


4.84 


52.55 


43.25 


5.25 


46.50 


45.51 


5.04 


50.55 


47.77 


4.83 


52.60 


43.30 


5.25 


48.55 


45.56 


5.04 


50.60 ■ 


47.82 


4.83 


52.65 


43.36 


5.24 


48.60 


45.62 


5.03 


50.65 


47.88 


4.82 


52.70 


43.41 


5.24 


48.65 


45.67 


5.03 


50.70 


47.93 


4.82 


52.75 


43.47 


5.23 


48.70 


45.73 


5.02 


50.75 


47.99 


4.81 


52.80 


43.52 


5.23 


48.75 


45.78 


5.02 


50.80 


48.04 


4.81 


52.85 


43.58 


5.22 


48.80 


45.84 


5.01 


50.85 


48.10 


4.80 


52.90 


43.63 


5.22 


48.85 


45.89 


5.01 


50.90 


48.15 


4.80 


52.95 


43.69 


5.21 


48.90 


45.95 


5.00 


50.95 


48.21 


4.79 


53.00 


43.74 


5.21 


48.95 


46.00 


5.00 


51.00 


48.26 


4.79 


53.05 


43.80 


5.20 


49.00 


46.06 


4.99 


51.05 


48.32 


4.78 


53.10 


43.85 


5.20 


49.05 


46.11 


4.99 


51.10 


48.37 


4.78 


53.15 


43.91 


5.19 


49.10 


46.17 


4.98 


51.15 


48.43 


4.77 


53.20 


43.96 


5.19 


49.15 


46.22 


4.98 


51.20 


48.48 


4.77 


53.25 


44.02 


5.18 


49.20 


46.28 


4.97 


51.25 


48.54 


4.76 


53.30 


44.07 


5.18 


49.25 


46.33 


4.97 


51.30 


48.59 


4.76 


53.35 


44.13 


5.17 


49.30 


46.39 


4.96 


51.35 


48.65 


4.75 


53.40 


44.18 


5.17 


49.35 


46.44 


4.96 


51.40 


48.70 


4.75 


53.45 


44.24 


5.16 


49.40 


46.50 


4.95 


51.45 


48.76 


4.74 


53.50 


44.29 


5.16 


49.45 


46.55 


4.95 


51.50 


48.81 


4.74 


53.55 


44.35 


5.15 


49.50 


46.61 


4.94 


51.55 


48.87 


4.73 


53.60 


44.40 


5.15 


49.55 


46.66 


4.94 


51.60 


48.92 


4.73 


53.65 


44.46 


5.14 


49.60 


46.72 


4.93 


51.65 


48.98 


4.72 


53.70 



Composition of Crkam 

TABLE 22 (Concluded) 



139 



Fat. 


S.N.F. 


T.S. 


Fat. 


S.N.F. 


T.S. 


Fat. 


S.N.F. 


T.S. 


49.03 


4.72 


53.75 


51.35 


4.50 


55.85 


53.66 


4.29 


57.95 


49.09 


4.71 


53.80 


51.40 


4.50 


55.90 


53.72 


4.28 


58.00 


49.14 


4.71 


53.85 


51.46 


4.49 


55.95 


53.77 


4.28 


58.05 


49.20 


4.70 


53.90 


51.51 


4.49 


56.00 


53.83 


4.27 


58.10 


49.25 


4.70 


53.95 


51.57 


4.48 


56.05 


53.88 


4.27 


58.15 


49.31 


4.69 


54.00 


51.62 


4.48 


56.10 


53.94 


4.26 


58.20 


49.36 


4.69 


54.05 


51.68 


4.47 


56.15 


53.99 


4.26 


58.25 


49.42 


4.68 


54.10 


51.73 


4.47 


56.20 


54.05 


4.25 


58.30 


49.47 


4.68 


54.15 


51.79 


4.46 


56.25 


54.10 


4.25 


58.35 


49.53 


4.67 


54.20 


51.84 


4.46 


56.30 


54.16 


4.24 


58.40 


49.58 


4.67 


54.25 


51.90 


4.45 


56.35 


54.21 


4.24 


58.45 


49.64 


4.66 


54.30 


51.95 


4.45 


56.40 


54.27 


4.23 


58.50 


49.69 


4.66 


54.35 


52.01 


4.44 


56.45 


54.32 


4.23 


58.55 


49.75 


4.65 


54.40 


52.06 


4.44 


56.50 


54.38 


4.22 


58.60 


49.80 


4.65 


54.45 


52.12 


4.43 


56.55 


54.43 


4.22 


58.65 


49.86 


4.64 


54.50 


52.17 


4.43 


56.60 


54.49 


4.21 


58.70 


49.91 


4.64 


54.55 


52.23 


4.42 


56.65 


54.54 


4.21 


58.75 


49.97 


4.63 


54.60 


52.28 


4.42 


56.70 


54.60 


4.20 


58.80 


50.02 


4.63 


54.65 


52.34 


4.41 


56.75 


54.65 


4.20 


58.85 


50.08 


4.62 


54.70 


52.39 


4.41 


56.80 


54.71 


4.19 


58.90 


50.13 


4.62 


54.75 


52.45 


4.40 


56.85 


54.76 


4.19 


58.95 


50.19 


4.61 


54.80 


52.50 


4.40 


56.90 


54.82 


4.18 


59.00 


50.24 


4.61 


54.85 


52.56 


4.39 


56.95 


54.87 


4.18 


59.05 


50.30 


4.60 


54.90 


52.61 


4.39 


57.00 


54.93 


4.17 


59.10 


50.35 


4.60 


54.95 


52.67 


4.38 


57.05 


54.98 


4.17 


59.15 


50.41 


4.59 


55.00 


52.72 


4.38 


57.10 


55.04 


4.16 


59.20 


50.47 


4.58 


55.05 


52.78 


4.37 


57.15 


55.08 


4.16 


59.25 


50.52 


4.58 


55.10 


52.83 


4.37 


57.20 


55.15" 


4.15 


59.30 


50.58 


4.57 


55.15 


52.89 


4.36 


57.25 


55.20 


4.15 


59.35 


50.63 


4.57 


55.20 


52.94 


4.36 


57.30 


55.26 


4.14 


59.40 


50.69 


4.56 


55.25 


53.00 


4.35 


57.35 


55.31 


4.14 


59.45 


50.74 


4.56 


55.30 


53.05 


4.35 


57.40 


55.37 


4.13 


59.50 


50.80 


4.55 


55.35 


53.11 


4.35 


57.45 


55.42 


4.13 


59.55 


50.85 


4.55 


55.40 


53.17 


4.33 


57.50 


55.48 


4.12 


59.60 


50.91 


4.54 


55.45 


53.22 


4.33 


57.55 


55.53 


4.12 


' 59.65 


50.96 


4.54 


55.50 


53.28 


4.32 


57.60 


55.59 


4.11 


59.70 


51.02 


4.53 


55.55 


53.33 


4.32 


57.65 


55.64 


4.11 


59.75 


51.07 


4.53 


55.60 


53.39 


4.31 


57.70 


55.70 


4.10 


59.80 


51.13 


4.52 


55.65 


53.44 


4.31 


57.75 


55.75 


4.10 


59.85 


51.18 


4.52 


55.70 


53.50 


4.30 


57.80 


55.81 


4.09 


59.90 


51.24 


4.51 


55.75 


53.55 


4.30 


57.85 


55.86 


4.09 


59.95 


51.29 


4.51 


55.80 


53.61 


4.29 


57.90 


55.92 


4.08 


60.00 



140 Standardization of Dairy Products 

ORDER OF OPERATIONS IN STANDARDIZING DAIRY PRODUCTS. 

The following order of operations is typical of that recom- 
mended in standardizing the majority of dairy products. 

The order as given will have to be departed from in some cases, 
but where possible to follow it can be the means of saving con- 
siderable time. Owing to the perishable nature of dairy prod- 
ucts it becomes necessary to study the various operations with 
the view of saving time where possible. 

(1.) Test as far in advance as possible all products that may 
be required when standardizing. Tests to include both fat and 
total solids where standardization might require both values to 
be known. 

(2.) About half an hour before the composite whole milk 
sample is ready, do everything necessary to begin making fat and 
total solids tests of the whole milk. Duplicate tests are recom- 
mended. If the operator is very careful in his work, a single de- 
termination may suffice. 

(3.) Keep the fat and total solids dishes in the respective 
ovens for five minutes under the proper heat and with the vac- 
uum on. 

(4.) Transfer the dishes from the ovens to the cooling desic- 
cators. Keep water circulating. Weigh the total solids dish with 
the cover on at the end of five minutes, and the fat dish alone at 
the end of seven minutes. Record weights and numbers upon the 
laboratory report. Replace dishes in the cooling desiccators. 

(5.) As soon as the composite whole milk sample reaches the 
laboratory, mix the same thoroughly by pouring back and forth 
at least six times into two vessels. 

(6.) Fill two gram pipette to the mark, and transfer the 
milk to the previously weighed dish and weigh the dish with the 
milk immediately. Or if preferred, the sample in the two gram 
pipette can be weighed from the weigh cross, or the weighing 
pipette. 

(7.) While one operator is weighing the sample as directed 
under (6) the second operator pipettes out 10 grams of whole milk 
into the fat extraction flask. 



Order of Operations 141 

(8.) One operator now prepares the total solids sample for 
the total solids oven and the second operator the fat sample for 
the fat oven. Dishes are heated in ovens, cooled in cooling desic- 
cators and weighed in accordance with the directions. 

(9.) Calculate the percentage of fat and the percentage of 
total solids and transfer the result to the proper report blank. 

(10.) Calculate the average pounds of material to add, using 
the proper method of calculation. 

(11.) Calculate the average fat and total solids test after 
having added the required pounds of skim-milk or cream. 

(12.) Calculate the pounds of water required, if any is nec- 
essary. Make retest for fat and total solids after adding water. 

PRINCIPLES OF METHOD OF CALCULATION WHEN STANDARD- 
IZING FOR BOTH FAT AND SOLIDS NOT FAT. 

In standardizing for both fat and solids not fat, the exact per- 
centage of these two constituents desired in the finished product 
must be known. A definite ratio between the two then exists as 
soon as the composition has been established. This ratio forms 
the basis for the entire calculation, inasmuch as the problem then 
resolves itself into calculating the pounds of fat and solids not fat 
required in any desired mixture of dairy products so that these 
may be in the same ratio one to the other as in the case of the 
product desired. 

For example, evaporated milk, testing 8.00 per cent fat, 18.15 
per cent solids not fat and 26.15 per cent total solids contains fat 
and solids not fat in the following ratio : 

8.00 : 18.15 = 1 : X 

X = 2.2687, the pounds solids not fat that a standardized 
batch should contain for every pound of fat present. 

The ratio can be calculated in several ways, which will be ex- 
plained in subsequent chapters. 



CHAPTER X 

CALCULATIONS WHEN STANDARDIZING 
WHOLE MILK AND CREAM 

In standardizing milk for its fat content without regard to its 
percentage of solids not fat, the usual practice is to add cream 
when it is necessary to raise the percentage of fat ; and to add 
skim-milk when it is necessary to lower it. However, in the ease 
of certain whole milk products it is frequently necessary to stand- 
ardize upon the double basis of fat and solids not fat. 

In standardizing cream it is seldom necessary, or desirable, to 
standardize upon any basis other than the fat alone. This is 
owing to the greater value of the fat as compared with the solids 
not fat, and also to the fact that the solids not fat in cream are 
always lower than in whole milk, and the same vary greatly with 
the content of the fat in the cream. 

■ In this chapter there are given methods of calculation covering 
the standardization of whole milk and cream upon the basis of 
the fat alone, and upon the double basis of the fat and solids not 
fat in the case of whole milk. 

A. HOW TO CALCULATE WHEN STANDARDIZING FOR FAT 

ALONE. 

The best method for standardizing for fat alone is the classic 
method devised by Prof. Pearson,^ or modifications of the Pearson 
method. This method is applicable to two different types of 
problems as follows: (1) When it is desired to make a product 
of definite fat test regardless of the resulting total weight; and 
(2) when it is desired to make a definite weight of product of a 
definite fat test. This method and its modification can be applied 
to milk, cream and several other dairy products. 

[142] 



Milk and Cream Mixtures 143 

PROBLEM 1: HOW TO CALCULATE WHEN IT IS DESIRED TO 

MAKE A PRODUCT OF DEFINITE FAT TEST REGARDLESS 

OF THE RESULTING TOTAL WEIGHT. 

A rectangle is drawn and the desired percentage of fat is 
placed in the center of it. The percentage of fat in each of the 
materials to be mixed together is placed at the left hand corners. 
The smaller number on the left hand corner is then subtracted 
from the number in the center, and the difference is placed in 
the diagonally opposite right hand corner. The number in the 
center is subtracted from the larger number at the left hand cor- 
ner and the difference is placed in the diagonally opposite right 
hand corner. The two numbers at the right hand corners repre- 
sent the number of pounds of each material to bring together in 
order to make a mixture containing the fat percentage indicated 
in the center of the rectangle. The number on the right hand 
corner refers to the substance represented by the number on the 
left hand corner directly opposite. 

PROBLEM 1: HOW TO CALCULATE WHEN MIXING TOGETHER 
WHOLE MILK AND CREAM. 

Standardizing for Fat Only. 

Problem 1, Example 1: Hoav many pounds of 30 per cent 
cream must be mixed with 900 pounds of 3.2 per cent milk to make 
a mixture testing 3.6 per cent of fat? 




26.4 



The smaller figure at the left is subtracted from the figure at 
the center, leaving a difference of .4. The figure at the center is 
subtracted from the larger figure at the left, leaving a difference 
of 26.4. This shows that .4 of a pound of 30 per cent cream must 
be mixed with 26.4 pounds of 3.2 per cent milk to form a mixture 



144 vStandardizing Mii,k and CrEam 

containing 3.6 per cent of fat. A calculation by simple proportion 
will give the total pounds of cream required as follows : 

.4 : 26.4 = X : 900 

X = 13.64 or the pounds of cream required. 

Proof: 

900 X .032= 28.80, lbs. fat in whole milk. 

13.64X .30 = 4.09, lbs. fat in cream. 

28.80+ 4.09 = 32.89, lbs. fat in mixture. 

900+ 13.64 =913.64, lbs. in total mixture. 

32.89-:-913.64 = 0.036, lbs. fat for one lb. of milk. 

0.036X100 = 3.60, per cent fat desired. 

PROBLEM 1. EXAMPLE 2: HOW TO CALCULATE WHEN MIXING 
TOGETHER WHOLE MILK AND BUTTER TO MAKE CREAM. 

Problem 1, Example 2: How many pounds of butter testing 
82.00 per cent fat must be mixed with 1,000 pounds of whole milk 
testing 3.75 per cent fat to make cream testing 18.00 per cent fat? 



14.25 




3.75 



As in the case of Example 1, the pounds of butter required are 
found by a calculation in simple proportion as follows: 

14.25 : 64 = X : 1000 

X=:222.6, the pounds of butter to use. 

Proof: 

1000 + 222.60=1222.6, or the pounds in total mixture. 

1000 X .0375=37.50, lbs. fat in whole milk. 

222.66 X .82=182.58, lbs. fat in butter. 

37.50 + 182.58=220.08, lbs. fat in mixture. 

220.08 H- 1222.60=0.18, lb. fat in one lb. cream. 

0.18 X 100=18.0, per cent of fat desired. 



Definite Weights oe Products 145 

PROBLEM 2: HOW TO CALCULATE WHEN IT IS DESIRED TO 
MAKE A DEFINITE WEIGHT OF PRODUCT OF A DEFINITE 

FAT TEST. 

This problem is solved most readily by a modification of the 
Pearson method devised by J. A. Cross. By the Pearson, method, 
the solution of this problem requires two subtractions, two addi- 
tions, two divisions and two multiplications. By the Cross modi- 
fication three subtractions, one division and one multiplication 
only are required. 

Solution Problem 2, based upon Rule 1 : 

Subtract the low test from the high tesi. Call remainder A. 
Subtract the low test from the standard desired. Call the differ- 
ence B. Divide B by A and multiply the result by the pounds of 
mixture desired. Call answer C, or the pounds of high testing 
material required. Subtract C from the total pounds required. 
The remainder will be the pounds of low testing material needed. 

Problem 2, Example 3 : 

How many pounds of milk containing 4.20 per cent of fat and 
skim-milk containing .1 per cent of fat must be mixed together 
to make 1000 pounds of milk testing 3.60 per cent fat? 

Solution Problem 2, Example 3, based upon Rule 1 : 

A'on~'i n X 1000=853.65, lbs. of 4.20 per cent milk required. 
1000—853.65=146.34, lbs. of skim-milk required. 

Proof Problem 2, Example 3 : 

853.65 X .042 = 35.85, pounds of fat in the whole milk. 
146.34 X .001 = .15, pound of fat in the skim-milk. 

35.85 + .15 = 36.00, pounds of fat in the mixture. 

36.00 -^1000 — 0.036, lb. fat for one lb. milk. 
0.036 X 100= 3.60, per cent of fat in the standardized milk. 



146 Standardizing Milk and Cream 

THE CROSS DIAGRAM METHOD 

J. A. Cross has developed another excellent improvement of the 
above method, all based upon the principle of allegation. This 
method can be used whenever it is desired to mix together two 
products of different tests with the object of obtaining a definite 
weight of a third product of a definite test, or also an indefinite 
weight of a third product of a definite test. 

PRINCIPLE OF THE CROSS DIAGRAM METHOD. 

Let A and B be the weights of two ingredients to be mixed to 
produce a weight (A -|- B) of mixture. Let a and b be the per- 
centages in the two ingredients of some component common to 
both of them ; and let m be the percentage of the same component 
in the final mixture. 

Then the total weight of the component in the mixture is the 
sum of the weights of that compound in the two ingredients. 
Formulated algebraically this is 

aA 4- bB = m (A + B) 

The above equation may readily be transformed into the fol- 
lowing : 

A : B : : (m — b) : (a — m) 

Designating a, b and m as composition percentages we can 
state the above equation in what is called the Principle of Alle- 
gation : — 

"The weights of two ingredients needed to prepare a given 
mixture are inversely proportional to the differences between the 
composition percentages of these ingredients and that of the mix- 
ture itself." 

Dr. Pearson's method presents the above principle graphically. 
His method of subtraction insures giving the values of (m — b) 
and (a — m), and his diagram also automatically shows that these 
values are in inverse proportion to A : B. 

The mixture diagrams illustrated under Figs. 57 and 58 carry 
this principle a little farther by automatically getting the values 
of (m — b) and (a — m), and by taking advantage of a simple 
geometric principle these values are made to add always to 100 
and can be considered as percentages. 



The Cross Diagram Method 147 

APPLICATION OF THE CROSS DIAGRAM METHOD. 

This method can be applied to the standardization of either 
milk or cream. The results are accurate within one-half of one 
per cent or less. The diagram under Fig. 57, applies to cream, 
and that under Fig. 58 applies to skim-milk and whole milk. 

PROBLEM 2, EXAMPLE 3A: MATERIALS ON HAND, 30.00 PER 

CENT CREAM AND 10.00 PER CENT CREAM. WANTED 100 

POUNDS OF 22.00 PER CENT CREAM. 

Solution Problem 2, Example 3A, based upon Cross Diagram 
Method : 

Lay a ruler across the diagram in such a way that it cuts 30 
per cent on the left and 10 per cent on the right hand vertical 
scales. Then where the ruler cuts the diagonal scale marked 22 
per cent, the pounds of 30 per cent cream can be read directly, 
namely, 60 pounds. The pounds of 10 per cent cream is then, of 
course, 40. 

In the same position, the ruler shows that 50 pounds of 30 per 
cent and 50 pounds of 10 per cent will produce 100 pounds of 20 
per cent cream. Also that 40 pounds of 30 per cent and 60 pounds 
of 10 per cent will produce 100 pounds of 18 per cent cream.. 

The correct proportions of materials of any other percentages 
can also be found in the same way. 

Other problems may also be solved by this method. 

Example 3B. 

On hand 865 pounds of 26 per cent cream. How much 3.5 per 
cent milk is necessary to reduce the percentage to 22 per cent? 

Solution Example 3B, based upon Cross Diagram Method : 

Mixture diagram shows that 82 parts cream and 18 parts milk 

are necessary. Therefore, 

865 

-^ 865^:^189, pounds 3.5 per cent milk necessary. 

.82 

Example 3C. 

On hand 625 pounds of 17.5 per cent cream. How much 40 
per cent cream must be added to raise the percentage to 22 per 
cent? 



148 



Standardizing Milk and CrEam 



Solution Example 3C, based upon Cross Diagram Method: 

Mixture diagram shows that the proportion is 20 parts 40 per 
cent to 80 parts 17.5 per cent, therefore 

625 

— ^-r 625=157, pounds of 40 per cent cream necessary. 

.80 



22 — 
















40 




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Pig-. 57. Cross Diagram Method for Standardizing- Cream. Hig-h Testing- 
Materials Vertical Big-ht Hand Column. Low Testing Materials Vertical 
Left Hand Column Test of Product Desired, also Percentag-e of Higrli Test- 
ing- Materials Kec[uired Upon Diagronal Scale. 



The; Cross Diagram Method 



149 



Either of the other scales (20 per cent or 18 per cent) will 
work in exactly the same way, or any desired scale can be 
sketched in. It would be very easilj^ possible to make a universal 
mixture diagram which would show the exact proportions of any 
two materials necessary to produce any desired percentage of an- 
other, and to arrange it in such a ^vay that the proportions would 
add to 100. 




Tig. 58. Cross Diagram Method for Standardizing- Milk. High Testing 
Materials Vertical Right Hand Column, low Testing Materials Vertical 
Left Hand Column. Test of Product Desired, also Percentage of High Test- 
ing Materials Required Upon Diagonal Scale. 



150 



Standardizing Milk and Cream 



ERF'S METHOD FOR SINGLE STANDARDIZATION. 

Another very excellent method for single standardization is 
that published by Prof. Erf.^ The method is based upon the mak- 
ing of suitable tables, and when these are once prepared the solu- 
tion desired is found by reference to the tables. Table 23 applies 
to the standardization of whole milk. 



TABLE 23. 

Quantity of skim-milk to be added to, or subtracted from, 100 pounds of 
milk to make milk of a desired percentage of fat. 



Per Cent 
Fat in 




Desired 


Percenta 


ge of Fat in Standardized 


Milk. 




Milk on 
Hand 


3.25 


3.50 


3.75 


4.0 


4.25 


4.50 
-33.333 


4.75 
-36.842 


5.0 


3. 


- 7.693 


-14.285 


-20.000 


-25.00 


-29.412 


-40.000 


3.1 


- 4.616 


-11.428 


-17.333 


-22.50 


-27.059 


-31.111 


-34.737 


-38.000. 


3.2 


- 1.539 


- 8.571 


-14.666 


-20.00 


-24.706 


-28.888 


-32.632 


-36.000 


3.3 


+ 1.539 


- 8.714 


-12.000 


-17.50 


-22.353 


-26.666 


-30.527 


-34.000 


3.4 


+ 4.616 


- 2.857 


- 9.333 


-15.00 


-20.000 


-44.444 


-28.422 


-32.000 


3.5 


+ 7.693 


- 0.000 


- 6.666 


-12.50 


-17.647 


-22.222 


-26.317 


-30.000 


3.6 


+ 10.760 


+ 2.857 


- 4.300 


-10.00 


-15.294 


-20.000 


-24.212 


-28.000 


3.7 


+ 13.837 


+ 5.714 


- 1.333 


- 7.50 


-12.941 


-17.777 


-22.107 


-26.000 


3.8 


+ 16.914 


+ 8.571 


+ 1.333 


- 5.00 


-10.588 


-15.555 


-20.000 


-24.000 


3.9 


+ 19.991 


+ 11.428 


+ 4.000 


- 2.50 


- 8.235 


-13.333 


-17.897 


-22.000 


4.0 


+23.068 


+ 14.285 


+ 6.666 


- 0.00 


- 5.882 


-11.111 


-15.792 


-20.000 


4.1 


+26.145 


+ 17.142 


+ 9.333 


+ 2.50 


- 2.429 


- 8.888 


-13.687 


-18.000 


4.2 


+29.222 


+ 19.999 


+ 12.000 


+ 5.00 


- 0.076 


- 6.666 


-11.582 


-16.000 


4.3 


+32.299 


+22.856 


+ 14.666 


+ 7.50 


+ 0.076 


- 4.444 


- 9.477 


-14.000 


4.4 


+35.476 


+25.713 


+ 17.333 


+ 10.00 


+ 2.429 


- 2.222 


- 7.372 


-12.000 


4.5 


+38.453 


+28.57 


+20.000 


+ 12.50 


+ 5.882 


- 0.000 


- 5.267 


-10.000 


4.6 


+41.530 


+31.427 


+22.666 


+ 15.00 


+ 8.235 


+ 2.222 


- 3.162 


- 8.000 


4.7 


+44.607 


+34.284 


+25.333 


+ 17.50 


+ 10.588 


+ 4.444 


- 1.057 


- 6.000 


4.8 


+47.684 


+37.141 


+28.000 


+20.00 


+ 12.941 


+ 6.666 


+ 1.057 


- 4.000 


4.9 


+50.761 


+39.998 


+30.666 


+22.50 


+ 17.647 


+ 8.888 


+ 3.162 


- 2.000 


5.0 


+53.828 


+42.855 


+33.333 


+25.00 


+20.000 


+ 11.111 


+ 5.267 


- 0.000 



To find the pounds of skim-milk to be added or removed, trace 
the vertical column of the desired per cent of fat to where the 
horizontal column presenting the percentage of fat in the milk on 
hand intersects ; the result will be tlie number of pounds of skim- 
milk to be added to or removed from 100 lbs. of milk, as indicated 
by a plus or minus sign before the figure. 



Key to Formulas 151 

TABLE 24. 
Standardization of Fat Only in Cream. 

Percentage quantity of cream of a desired fat content made from cream of 
a certain fat content by diluting with milk containing 4 per cent of butter fat. 



Per Cent 










Fat in 


Desired Percentas;e of Fat in Standardized Cream 


Cream 






















on Hand 


17 


20 


22 


25 


27 


30 


18 


92.857 












19 


86.666 












20 


81.250 


100 










21 


76.4706 


94.706 










22 


72.2222 


88.8888 


100 








23 


68.4222 


84.2222 


94.2125 








24 


65.0000 


80.0000 


90.0000 








25 


61.905 


76.1905 


85.7143 


100 






26 


59.0909 


72.7272 


81.8181 


95.4545 






27 


56.5217 


69.5651 


78.2608 


91.3044 


100 




28 


54.1666 


66.6666 


75.0000 


87.5000 


95.8333 




29 


52.0000 


64.0000 


72.0000 


84.0000 


92.0000 




30 


50.0000 


61.5385 


69.2308 


80.3461 


88.4615 


100.00 



If cream is to be standardized with 4 per cent milk, the result 
found by the intersecting columns represents the pounds per hun- 
dred, or the percentage of the quantity which is cream on hand 
containing the percentage of fat as indicated. 

Example : If cream containing 20 per cent of butterfat is de- 
sired and cream containing 26 per cent of fat is on hand, then 
72.7 per cent of the quantity desired must be cream containing 26 
per cent of fat and 27.3 per cent of the quantity must be 4 per 
cent milk. 



B. HOW TO CALCULATE WHEN STANDARDIZING WHOLE MILK 
OR CREAM FOR BOTH FAT AND SOLIDS NOT FAT. 

Key to Formulas for Standardizing- Whole Milk. 

The following key gives the information required for substi- 
tuting values for letters in the formulas found in this chapter : 
A = The percentage of fat desired in the standardized prod- 
uct. 



152 Standardizing Mii.k and Cream 

D =: The pounds of skim-milk required for standardizing. 
F =: The percentage of fat in the whole milk. 
G = The percentage of fat in the cream, 
H = The percentage of fat in the butter. 
J = The percentage of S. N. F. in the cream. 
K == The percentage of fat in the skim-milk. 
L = The percentage of fat in the skim-milk powder. 
N = The percentage of S. N. F. in the skim-milk. 
M =The percentage of S. N. F. in the skim-milk powder. 
M'= The pounds of butter required or on hand. 
= The pounds of cream required for standardizing. 
0'=: The pounds of skim-milk powder required. 
P = The pounds of whole milk in the batch. 
Q = The pounds of cream desired. 

R = The ratio of S. N. F. to fat in the desired product. 
S = The percentage of S. N. F. in the whole milk. 
S':= The average percentage of fat in the mixed batch. 
W= The pounds of water to be added. 

METHOD OF HANDLING PRODUCTS. 

Cream and skim-milk are the products used in the process of 
standardizing whole milk. They are usually secured by separat- 
ing some of the batch of whole milk on hand. 

It is best to remove a little more than the theoretical amount, 
since a small amount of fat remains in the skim-milk. The skim- 
milk is cooled and run into a separate tank, and after thoroughly 
mixing a sample is collected for the fat and total solids test. The 
cream is likewise promptly cooled, mixed and tested for fat. 
Where it is desired to make a homogenized product, the fresh 
milk, cream and skim-milk are to be properly homogenized before 
testing. All products should be carefully weighed, as otherwise 
inaccuracies will result. Where impracticable to weigh, convert 
gallons into pounds. 

When skim-milk is separated in excess of the amount required 
to standardize the whole milk, the excess may be standardized 
back to the composition of whole milk by adding the proper 
amount of cream. The aim in plant management should be to 
use each day all the by-products to the best advantage. When a 
product must be held over until the next day, there is usually 



Pounds of Milk Separated 153 

less liability of loss if it is held in the form of cream. After 
learning the average fat and total solids test by means of the 
Mojonnier Tester, and the pounds of whole milk in the batch, 
the pounds necessary to separate to secure the cream, and the 
skim-milk for use in standardizing may be calculated as follows : 

PROBLEM 3: HOW TO CALCULATE POUNDS OF WHOLE MILK 

TO SEPARATE, TO OBTAIN CREAM AND SKIM-MILK 

NECESSARY TO STANDARDIZE BATCH. 

Solution Problem 3 by Formula 1, 

-^ IP = pounds of milk to remove to separate. 

Problem 3, Example 4: 

Lbs. of whole milk in batch = 10,000. 

Test of whole milk = 4.00 per cent fat, 8.60 per cent S. N. F. 
and 12.60 per cent T. S. 

Standardized product to test 3.25 per cent fat, 8,50 per cent 
S. N. F. and 11.75 per cent T. S. 

Solution of Example 4, Based Upon Formula 1 : 

4.00 — 3.25 = .75, per cent of fat in excess. 
10,000 X .0075 = 75, pounds of fat in excess. 

75 -^ .04^=1875, pounds of milk to be skimmed. 
10,000 — 1875 =: 8125, pounds milk containing enough fat to 

make 10,000 pounds of milk testing 3.25 per cent of fat. 
Separate 1875 lbs. of whole milk into cream and skim-milk to 
be used for standardizing purposes. 

PROBLEM 4: HOW TO CALCULATE THE AMOUNT OF SKIM- 
MILK TO ADD TO WHOLE MILK. 

"When it is necessary to add skim-milk the ratio between the 
per cent S. N. F. and fat in the whole milk must be more than the 
required ratio. 

Solution of Problem 4 by Rule 2 : 

(1.) Divide the percentage of fat in the skim-milk by the 
ratio between the S. N. F. and the fat in the product desired. 
Subtract the answer from the S. N. F. in the skim-milk. Call the 
remainder A, or the percentage of S. N. F. in the skim-milk avail- 
able for standardizing. 



154 



Standardizing Milk and Cream 



(2.) Divide the percentage of fat in the whole milk by the 
ratio between the S. N. F. and the fat in the product desired. 
Call the result B. Subtract from B the percentage of S, N, F. 
present in the whole milk. Multiply the remainder by the pounds 
of whole milk in the batch. Call result C. 

(3.) Divide C by A. The answer will be the number of 
pounds of skim-milk necessary to standardize the batch to the 
required ratio. 

(4.) Add together the pounds of whole and skim-milk in the 
mixed batch. Multiply the pounds of whole and skim-milk by 
their respective percentages of fat ; add together the two results, 
and divide the sum by the total pounds milk products in the 
mixed batch. Call the answer D, or the percentage of fat in the 
mixed batch. 

(5.) Subtract from D the percentage of fat desired. Mul- 
tiply the pounds in the mixed batch by the remainder and divide 
the answer by the percentage of fat desired. The result will be 
the pounds of water necessary to add. 

Solution Problem 4 by Formula 2: 

(1.) To calculate the pounds of skim-milk required. 



P ^ 



D 



KiH 



(2.) To calculate the average fat test of the mixed batch. 

DK + PF 



S' 



DP 



(3.) To calculate the pounds of water required. 

^^,^ (S^ -A) (P + D ) 



Problem 4, Example 5: 



Products 


Pounds 


Per Cents 


Fat 


S. N. F. 


T. S. 


Whole Milk 


10,000 


3.77 

.16 

3.25 


8.58 
8.55 
8.50 


12.55 


Skim-milk 


8.71 


Composition of product desired. . 




11.75 



Pounds of Milk Separated 155 

Ratio S. N. F. to fat desired is 1 to .3824. 
Solution of Example 5, based upon Rule 2: 

(1.) To calculate the percentage of available S. N. F. in the 
skim-milk. 

.16 -^ .3824 = .42, per cent of S. N, F. required to equalize the 
fat in the skira-milk. 

8.55 — .42 = 8.13, per cent of S. N. F, available for standard- 
izing. 

(2.) To calculate the pounds of S, N. F. short. 
' 3.77 -:- .3824 r= 9.86, per cent of S. N. F. required. 

9.86 — 8.58 = 1.28, per cent of S. N. F. short. 
10,000 X .0128 = 128, pounds of S. N. F. short. 

(3.) To calculate the pounds of skim-milk required. 
128-."- .0813 =: 1574, pounds of skira-milk required. 
(4.) To calculate the average fat test of the mixed batch. 
10,000+1574=11574, total pounds of milk products in mixed 
batch. 

10,000X. 0377=377, pounds of fat in whole milk. 
1574X. 0016=2.52, pounds of fat in skim-milk. 
377 + 2.52 = 379.52, total pounds of fat in mixed batch. 
379.52 ~ 11574 = 3.28, per cent of fat in mixed batch. 

(5.) To calculate pounds of water required. 
3.28 — 3.25 = .03, per cent of fat in excess. 
11574 X .0003 = 3.47, pounds of fat in excess. 
3.47 -:- .0325 = 107, pounds of water to add. 

Solution of Example 5, based upon Rule 2 : 

(1.) To calculate the pounds of skim-milk required. 



D = 



r/.0377\ 
''''' L(^82ij - -^^^^ 
/.0016\ 



1574 



{2.) To calculate the average fat test of the mixed batch. 

)016) 4- (1000 

10,000 -j- 1574 



g, ^ (1574 X .0016) 4- (10000 X .0377) ^^^^ 



156 Standardizing Milk and Cr^am 

(3.) To calculate the pounds of water required. 

(.0328 — .0325) X (10000 + 1574) 



W 



.0325 



--=107 



In the above example no factor of safety was allowed. 
Proof for Problem 4, Example 5: 



Products in Batch 


Pounds 




Fat 


Solids Not Fat 


After 
Standardizing 


Per Cent 


Pounds 


Per Cent 


Pounds 


Whole milk 

Skim-milk 


10000 

1574 

107 


3.77 
.16 


377.00 
2.52 


8.58 
8.55 


858.00 
134.58 


Water 














Total pounds and 
average test of 
mixed batch . . . 


11681 


3.25 


379.52 


8.50 


992.58 



PROBLEM 5: HOW TO CALCULATE THE POUNDS OF CREAM 
TO ADD TO WHOLE MILK. 

When it is necessary to add cream, the ratio between the per- 
centage of S. N. F. and fat in the whole milk must be less than 
the required ratio. 

Solution of Problem 5 by Rule 3 : 

(1.) Multiply the percentage of S. N. F. in the cream by the 
ratio between the S. N. F. and the fat in the product desired. 
Subtract the result from the percentage of fat in the cream. Call 
the remainder A, or the percentage of fat in the cream available 
for standardizing. 

(2.) Multiply the percentage of S. N. F. in the whole milk 
by the ratio between the S. N, F. and the fat in the product de- 
sired. Call the result B, or the percentage of fat required. Sub- 
tract from B the percentage of fat present in the whole milk. 
Multiply the remainder by the pounds of whole milk in the batch. 
Call the result C, or the pounds of fat short. 

(3.) Divide C by A. The answer will be the pounds of cream 
required to standardize the batch to the desired ratio. 

(4.) Add together the pounds of whole milk and cream in 
the batch. Multiply the pounds of whole milk and cream by their 



Calculating Whole Milk 



157 



respective percentages of fat; add together the two results and 
divide the sum by the total pounds of milk products in the mixed 
batch. Call the answer D or the percentage of fat in the mixed 
batch. 

(5.) Subtract from D the per cent of fat desired. Multiply 
the pounds in the mixed batch by the remainder and divide the 
answer by the per cent of fat desired. The result will be the 
pounds of water necessary to add. 

Solution of Problem 5 by Fornmla 3 : 

(1.) To calculate the pounds of cream required. 

RS — PF 







G— (JR) 



(2.) To calculate the average fat test of the mixed batch. 

OG + PF 



S> 



04-P 



(3.) To calculate the pounds of water required. 

(S^-A) (0 + P) 
W = 1 



Problem 5, Example 6 : 



Products 


Pounds 




Per Cfnts 




Fat 


S. N. F. 


T. S. 


Whole milk 


10,000 


3.05 

22.05 

3.25 


8.60 
6.50 
8.50 


11.65 


Cream 


28.55 


Composition of product desired. . 




11.75 



Ratio of S. N. F. to fat desired is 1.0 to .3824. 
Solution of Example 6, based upon Rule 3: 

(1.) To calculate the percentage of available fat in the cream. 

6.50 X .3824 = 2.49, per cent of fat required to equalize the 
S. N. F. in the cream. 

22.05 — 2.49 — 19.56, per cent of fat in the cream available for 
standardizing. 



158 Standardizing Milk and Cream 

(2.) To calculate the pounds of fat short. 
8.60 X .3824 = 3.29, per cent fat required. 
3.29 — 3.05 = .24, per cent of fat short. 
10,000 X .0024 rrr 24, pounds of fat short. 

(3.) To calculate the pounds of cream required. 
24-=-.1956=:123, pounds of cream required. 

(4.) To calculate the averag^e fat test of the mixed batch. 

10,000 X .0305 = 305, pounds of fat in the whole milk. 

123 X .2205 = 27, pounds of fat in the cream. 

305 -f- 27 = 332, pounds of fat in the mixed batch. 

10,000 + 123 = 10123, pounds of milk products in mixed batch. 

332 ~ 10123 = 3.28, per cent of fat in mixed batch. 

(5.) To calculate the pounds of water required. 
3.28 — 3.25 = .03, per cent of fat in excess. 
10123 X .0003 = 3.03, pounds of fat in excess. 
3.03 ~ .0325 = 93, pounds of water to add. 

Solution of Example 6, based upon Formula 3 : 

(1.) To calculate the pounds of cream required. 

[ (.3824 X .0860) — (10,000 X .0305) ] 

O = •- -^ — = 123 

.2205— (.0650 X .3824) 

(2.) To calculate the average fat test of the mixed batch. 

g _ (123 X .2205) 4- (10,000 X .0305 ) __ ^ ^g 
~ 123 + 10,000 

(3.) To calculate the pounds of water required. 

^ ^ (.0328— .0325) X (10,000+123) ^ ^^ 
.0325 

In the above example no factor of safety is allowed. 



Use of Butter 



159 



Proof for Example 6 : 



Products in Batch 


Pounds 


Fat 


Solids Not Fat 


After 
Standardizing 


Per Cent 


Pounds 


Per Cent 


Pounds 


Whole milk 

Cream 


10000 

123 

93 


3.05 
22.05 


305 
27 


8.60 
6.50 


860. 

8 


Water 














Total pounds and 
average test of 
mixed batch . . . 


10216 


3.25 


332 


8.50 


868. 



PROBLEM 6: HOW TO CALCULATE WHEN MIXING BUTTER AND 
SKIM-MILK POWDER TO MAKE WHOLE MILK OR CREAM. 

Two variations of this problem are encountered in plant prac- 
tice. 

(a) When the two products are mixed together with the 
view of obtaining a product of definite fat test regardless of the 
resulting total weight, and (b) when it is desired to make a defi- 
nite weight of product of a definite fat test. Examples covering 
the two kinds of problems will be given. The same method of 
calculation under the above two variations can be followed when 
it is desired to make either whole milk or cream. Solution of 
these problems by means of formula only are given herewith. 

Solution of Problem 6, Variation A based upon Formula 4: 

(1.) To calculate the pounds of skim-milk powder required. 



0^ = 



QJ 
M 



(2.) 



(3.) 



To calculate the pounds of butter required. 
QA — O^L 



M^ 



H 



To calculate the pounds of water required. 

W=:Q— (M^ + O^) 
Problem 6, Variation A, Example 7: 

Wanted to make 1,000 pounds of cream testing 18.00 per cent 
of fat and 7.59 per cent of S. N. F. when using butter testing 



160 



Standardizing Milk and CrEaM 



82.00 per cent of fat and skim-milk powder testing 1.00 per cent 
of fat and 94.00 per cent of S. N. F. 

Solution of Example 7, based upon Formula 4: 

(1.) To calculate the pounds of skim-milk powder required. 

^.^ 1000 X. 0759^3,, 
.94 

(2.) To calculate the pounds of butter required. 

Ml ^ (1000 X .18) - (80.7 X .01) ^ 218 5 
.82 
(3.) To calculate the pounds of water required. 

W = 1000 — (218.5 + 80.7) = 700.8 
In the above example no factor of safety was allowed. The 
small amount of S. N. F. in the butter was disregarded. 

Proof of Problem 6, Example 7 : 



Products in Batch 


Pounds 


Fat 


Solids Not Fat 


After 
Standardizing 


Per Cent 


Pounds 


Per Cent 


Pounds 


Skim-milk powder . . 
Butter 


80.7 
218.5 
700.8 


1.00 
82.00 


.8 
179.2 


94.00 


75.9 


Water 
















Total pounds and 
average test of 
mixed batch . . . 


1000.0 


18.00 


180. 


7.59 


75.9 



Solution of Problem 6, Variation B, based upon Formula 5: 

(1.) To calculate the pounds of whole milk possible to make. 
^ M^ H 



(2.) To calculate the pounds of skim-milk powder required. 

PF 



0V= 



M 



(3.) To calculate the pounds of water required. 

W=rP— (M^ + O^) 



Use of Skim-I\Iii.k Powder 



161 



Problem 6, Variation B, Example 8: 

Wanted to make as much whole milk as possible testing 3.75 
per cent of fat, and 8.50 per cent of S. N. F. from 50 pounds of 
butter testing 82.00 per cent of fat, and skim-milk powder testing 
1.00 per cent of fat and 94.00 per cent of S. N. F. 

Solution of Example 8, based upon Formula 5 : 

(1.) To calculate the pounds of whole milk possible to make. 

50 X .82 



P=: 



.0375 



1093 



(2. 



(3.: 



To calculate the pounds of skim-milk powder required. 

1093 X .085 



0^ = 



.94 



98.8 



To calculate the pounds of water required. 

W = 1093 — (50 + 98.8) = 944.2 



In the above example the fat in the skim-milk powder and 
the S. N. F. in the butter were disregarded, as the amount of these 
constituents is too small to affect appreciably the results. 

Proof of Problem 6, Example 8 : 



Products in Batch 


Pounds 


Fat 


Solids 


Not Fat 


After 
Standardizing 


Per Cent 


Pounds 


Per Cent 


Pounds 


Skim-milk Powder. . 
Butter 


98.8 

50.0 

944.2 


1.00 
82.00 


Disregard 'd 
41.0 


94.0 
1.00 


92.9 
Disregard'd 


Water 














Total pounds and 
average test of 
mixed batch . . . 


1093.0 


3.75 


41.0 


8.50 


92.9 



iPearson, R. A., Cornell Farmer.s Reading Course, Bui. 22, 1904. 
-Erf, O.scar, 111. Sta. Bui. No. 75. 



CHAPTER XI 

STANDARDIZING EVAPORATED MILK 

The principle underlying the entire practice of standardizing 
evaporated milk is based upon mixing together milk and the 
products obtained from milk in the proper proportions to make 
a product that contains the fat and the S. N. F. in the same ratio 
that they are to have in the standard product which it is desired 
to manufacture. These ratios can be obtained by referring to 
Table 25, page 165. They are derived by dividing the percentage 
of one constituent into the percentage of another constituent of 
the standard product. For example, standard domestic evapo- 
rated milk which tests 8.00 per cent fat, 18.15 per cent of S. N. F. 
and 26.15 per cent of T. S. gives a ratio between the S. N. F. and 
fat of 18.15 to 8.0, or 1 to .4407. 

Evaporated milk may also be standardized upon the basis of 
the fat only, or of the S. N. F. only. In such cases the unstandard- 
ized constituent will be, in the majority of cases, in excess of the 
standard requirements. 

Two general methods of standardizing evaporated milk are 
possible, namely before condensing and after condensing. In 
standardizing before condensing, the fat and the S. N. F. are 
placed in the proper proportion one to the other in the initial 
product, so that, after condensing, the product obtained can be 
either of exactly the standard required, or if overcondensed, it 
can be diluted back to the proper standard with water only. This 
chapter contains methods with examples that accompany the 
same, covering every known condition that may be encountered 
in plant practice, where evaporated milk is standardized both for 
fat and S. N. F. both before and after condensing. 

It is frequently impossible to standardize the initial products 
before condensing. This is particularly true when the multibatch 
system is used, as in that case there is scarcely time to make the 
required tests upon the fresh milk. However, this usually can 

[ 162] 



Steps in Standardizing 163 

be so arranged by careful planning, and when possible the initial 
product should be standardized, as in that case all that is neces- 
sary is to add sufficient water after condensing to bring the evapo- 
rated product back to the desired standard. 

Where the condensed product is standardized, this can be ac- 
complished in several ways. In such cases, it is best for the prod- 
uct to come from the pan overcondensed, rather than undercon- 
densed, as it is possible to add more accurately the materials re- 
quired for standardizing when the batch is overcondensed rather 
than when the opposite is the case. Standardizing after condens- 
ing can be accomplished by one or more of the following methods : 

(1.) By the addition of water alone. This is the simplest 
standardization of all. 

(2.) By the addition of homogenized, pasteurized cream 
alone. 

(3.) By the addition of homogenized, condensed skim-milk. 
(If very low in fat, the homogenization can be omitted.) 

(4.) By the addition of water and homogenized, pasteurized 
cream. 

(5.) By the addition of water and homogenized, condensed 
skim-milk. 

(6.) By the addition of water, homogenized cream and homog- 
enized condensed whole milk. 

SUCCESSIVE STEPS IN STANDARDIZING EVAPORATED MILK 
REFORE CONDENSING 

The steps involved in standardizing evaporated milk are as 
follows : 

(1.) Obtaining a representative composite sample of the en- 
tire lot of whole milk which goes to make up the batch ; likewise 
of the skim-milk, cream, butter or other products which might be 
used in standardizing. 

(2.) Testing of all of the above products involved, for both 
fat and S. N. F. or T. S. by means of the Mojonnier Tester. In 
the case of the S. N. F. in cream, it usually suffices to obtain the 
S. N. F. from Table 22. In the case of unsalted butter, the amount 
of S. N. F. is so small as to be disregarded. 

(3.) Calculating the weight of each product to be used, by 
uiethods which follow, in order to make the fat and the S. N, F, 



164 Standardizing Evaporatr;!) Milk 

in the initial product of the same ratio as these are to occur in the 
finished product. 

(4.) When the initial product has been standardized so that 
the fat and the S. N. F. are in the required ratio, the same is to 
be condensed down to the desired specific gravity to yield a fin- 
ished product of the test required. In practice it is well to con- 
dense the batch to a little higher concentration than desired, as it 
then becomes possible to bring it back to the desired point by the 
mere addition of water. If the concentration of the batch should 
be less than the required concentration it becomes necessary either 
to recondense part of the batch or condense another batch to add 
to it, which makes it a very much more difficult and involved 
problem than when it is necessary to add water only. Or if the 
plant should have concentrated pasteurized and homogenized 
cream, or condensed, homogenized whole milk available, these 
might be added, as the case might require. When the final prod- 
uct obtained from the pan contains an excess of fat over the 
S. N, F. the error may be corrected by adding condensed skim- 
milk if this is possible or practicable. Likewise if it contains an 
excess of S. N. F. over fat the error can be corrected by adding 
concentrated pasteurized and homogenized cream if this is avail- 
able. 

METHOD OF COLLECTING COMPOSITE MILK SAMPLES. 

No fixed method of sampling is recommended that can be ap- 
plied to meet all the varying conditions of different plants. This 
important matter will need careful study at each plant, in order 
to determine the procedure that will give the most accurate sam- 
ples. The reader is referred to Chapter VI for complete informa- 
tion upon this point. 

METHOD OF TESTING 

Use the Mojonnier Tester for making all fat and T, S. determin- 
ations, upon all products used in standardizing. The skim-milk 
and cream should be tested before the composite sample of the 
whole milk reaches the laboratory. The S. N. F. in the cream 
can be ascertained from Table 22, as the total amount of the same 
is usually small. As it is necessary to complete the fat and T. S. 
tests of the whole milk while the last forewarmer is being heated 
and drawn into the pan, these tests should be made as rapidly as 



Evaporated Milk Constants 



165 



possible. A short time before the sample is ready the tempera- 
ture of the hot plates and ovens should be regulated ; a fat and 
T. S. dish cooled and weighed ; clean glassware and a weigh cross 
prepared for use and everything put into readiness for making 
the test. By systematizing the successive steps, the time for com- 
pleting the fat and T. S. tests, including the total time for making 
the calculations, should not exceed twenty-five or thirty minutes, 
counting from the time the sample reaches the laboratory. Under 
some conditions it may be desirable to give the operator a helper 
while making the tests, as this would greatly expedite the opera- 
tions. 

CONSTANTS FOR EVAPORATED MILK 

The following table gives the constants for evaporated milk, 
both domestic and export. This is based upon standards now in 
force in this country and in Canada, and upon the standards called 
for in the European requirements. Domestic evaporated milk is 
given upon the double basis of 7.80 per cent of fat and 25.50 per 
cent of T. S. and 8.00 per cent of fat and 26.15 per cent of T, S. 

TABLE 25. 
Constants for Evaporated Milk. 





Export 


Domestic 


Domestic 


Constants 


Evaporated 


Evaporated 


Evaporated 




Milk 


Milk (A) 


Milk (B) 


Per cent fat 


9.25 
16.75 
26.00 

2.811 


7.80 
17.70 
25.50 

3.2692 


8 00 


Per cent S. N. F 


18 15 


Per cent total solids 


26 15 


Ratio per cent fat to per cent total solids. . . 


3.2687 


Ratio per cent fat to per cent S. N. F 


1.811 


2.2692 


2.2687 


Ratio per cent S. N. F. to per cent fat .... 


.5522 


.4407 


.4408 


Ratio per cent S. N. F. to per cent total solids 


1 . 5522 


1 . 4407 


1.4408 


Ratio per cent total solids to per cent fat . . 


.3558 


.3059 


.3059 


Net weight per can, ozs. Baby size 


6.0 


6.0 


6.00 


Net weight per can, ozs. Family size 


12.0 


12.0 


12.00 


Net weight per can, ozs. Tall size 


16.0 


16.0 


16.00 


Net weight per can, ozs. Hotel size 


32.0 


32.0 


32.00 


Net weight per can, ozs. Gallon size 


136.0 


136.0 


136.00 


Net weight per case, pounds. Baby size . . . 


27.0 


27.0 


27.00 


Net weight per case, pounds. Family size. . 


36,0 


36.0 


36.00 


Net weight per case, pounds. Tall size .... 


48.0 


48.0 


48.00 


Net weight per case, pounds. Hotel size. . . 


48.0 


48.0 


48.00 


Net weight per case, pounds. Gallon size. . 


51.0 


51.0 


51.00 



166 . Standardizing EvAPORATJiD Milk 

METHOD OF GETTING WEIGHTS. 

The one who does the standardizing should be sure that the 
pounds of whole milk, and likewise the pounds of cream or skim- 
milk used are correctly reported and properly checked. 

ORDER OF OPERATIONS IN STANDARDIZING EVAPORATED 
MILK BEFORE CONDENSING, USING MOJONNIER TESTER. 

(1.) Test, as far in advance as possible, the cream sample for 
fat. Obtain the S. N. F. test of the cream from Table 22, or, if 
necessary, test the skim-milk or the bulk condensed milk, for both 
fat and T. S. 

(2.) About half an hour before the composite whole milk sam- 
ple is ready, do everything necessary to begin making fat and 
T. S. tests of the whole milk. It is recommended that the tests be 
made in duplicate. If the operator is very careful in his work, a 
single determination may suffice. 

(3.) Keep the fat and the T. S. dishes in the respective ovens 
for five minutes, under proper heat, and with the vacuum on. 

(4.) Transfer dishes from the ovens to cooling desiccators. 
Keep water circulating through the cooling desiccators. Weigh 
the T. S. dish with the cover on at the end of five minutes, and the 
fat dish alone, at the end of seven minutes. Record the weights 
and numbers upon the laboratory report. Fig. 59. Replace dishes 
in the cooling desiccators. 

(5.) As soon as the composite wliole milk sample reaches the 
laboratory, mix the same thoroughly by pouring back and forth 
at least six times using two vessels. 

(6.) Fill a two gram pipette to the mark, and transfer the 
milk to the previously weighed dish, and immediately weigh the 
dish with the milk. Or, if preferred, the sample in the two gram 
pipette can be weighed from the weigh cross. 

(7.) While one operator is weighing the sample as under (6) 
the second operator pipettes out 10 grams into the fat extraction 
flask. 

(8.) One operator now prepares the T. S. sample for the T. S. 
oven and the second operator the fat sample for the fat oven. 



Ordkr Of* Operations 167 

Dishes are heated in ovens ; cooled in oooling desiccators and 
weighed in accordance with directions. 

(9.) Calculate the percentage of fat, and the percentage of 
T, S. and transfer the results to the evaporated milk report blank. 

(10.) Calculate the pounds of material to add, using the 
method that may apply, selecting the proper one, beginning with 
Rule 4, and ending with Rule 15. 

(11.) Test the finished product for fat and T. S. and enter the 
results upon the evaporated milk report, Fig. 60. 

(12.) Divide the percentage of fat by the percentage of T. S. 
to get the ratio of T. S. to fat in the finished product. 

(13.) If the condensation is not otherwise obtained, divide 
the percentage of T. S. in the finished product by the percentage 
of T. S. in the initial product. 

(14.) Divide the total weight of raw products used by the 
condensation to obtain the pounds in the batch after condensing. 

, (15.) Add water, if necessary, using either Rule 10 or 11, 
Make a retest for fat and T. S. after adding water. 

(16.) Calculate the weight of milk from the cans filled, and 
figure loss in handling due to overfilling. 

ORDER AND OPERATIONS IN STANDARDIZING EVAPORATED 
MILK AFTER CONDENSING, USING THE MOJONNIER TESTER. 

(1.) Test, as far in advance as possible, the cream sample for 
fat. Obtain the S. N. F. test of the cream from Table 22, or, if 
necessary, test the condensed skim-milk or the condensed whole 
milk for both fat and T. S. 

(2.) About half an hour before the condensed batch is all 
completed, do everything necessary to begin making the fat and 
the T. S. tests. 

(3.) Keep the fat and the T. S. dishes in the respective ovens 
for five minutes, under proper heat, and with tlie vacuum on. 

(4.) Transfer the dishes from the ovens to the cooling desic- 
cators. Keep the water circulating. Weigh the T. S. dish with 
cover at the end of five minutes, and the fat dish alone at the end 
of seven minutes. Record the weights and numbers upon the 



168 



Standardizing Evaporatkd Milk 



laboratory report, Fig.. 59. Replace the dishes in the cooling 
desiccators. 

(5.) Mix the sample from the condensed batch very thor- 
oughly. 

FOR EVAPORATED AND CONDENSED MILK PLANTS 

Laboratory Report 



Pf.ANT 


Te 
BA 








DATE 


TCH No. 






TK8T 












CO«roS,,E 


OISB 














DISH 














PAT 














PIPETTES 














PIPETTES 














MILI 














i 

FAT 












,.;:r:;u 
















DISH 














SOUDS 














PIPETTES 














PIPETTES 














MIU 














SOLIDS 












..„,*vjl,';jd.„ 


""JT 














""■<„;;■* 




j:.Er_ 




mUi.ik miU, 






'•';■-;% 








•tsSriiiir 






.'.u. 




I:St"™u'" 




IfcONo'ENS^J 







MOJONNIBR BROB. CO. 



Pig-. 59. Evaporated Milk Iiaboratory Report. 

(6.) Fill the one gram pipette to the mark, and transfer the 
milk to the previously weighed dish, and immediately weigh the 
dish with milk. Or, if preferred, the sample in the one gram 
pipette can be weighed from the weigh cross. Fill the five grams 
pipette to the mark, and by means of the weighing cross, weigh 
about five grams into the fat extraction flask. 

(7.) One operator now prepares the T. S. sample for the T. S. 
oven and the second operator the fat sample for the fat oven. 
Dishes are heated in ovens, cooled in cooling desiccators, and 
weighed in accordance with directions. 

(8.) Calculate the percentage of fat and the percentage of 
T. S. and transfer results to evaporated milk report, Fig. 60. 

(9.) Calculate the pounds of material necessary to add, se- 
lecting and using the rule that may apply. 

(10.) Mix the batch very thoroughly, after adding the ma- 
terial for standardizing. 



Blanks for Recording Data 



169 



Make a retest for fat and T. S. 

(11.) Divide the percentage of fat by the percentage of T. S. 
to get the ratio between the T. S. and the fat in the finished 
product. 

(12.) Complete all possible or necessary calculations upon 
the evaporated milk report, Fig. 60. 

BLANK FOR RECORDING STANDARDIZING DATA. 

It is important to use proper blank reports for recording all 
data in connection with the standardization of evaporated milk. 
A specially designed blank report is illustrated under Fig. 60. 
The blank is designed so that the uecessary facts covering an en- 
tire day's milk can be ascertained at a glance. 



EVAPORATED MILK REPORT 

Plant Bitch^o^ 



WK 


K£.SG 


■•■■^ 


'3t.- 


-■■s= 


^.-s. 


.S'Ji 


"i.ir 


"■■-"l-M: 


















1 




rr- 


UMIUTOIIV Tt«T« 


"°~™"»<"'"° 


uw.«»»cn 


nn»ui«>i«rT 


CPTAinO 


,f. 


•JW 


ar 


,•. 


• ri 




.-,-. 












riui 


« 






>-.— _ 










sa=z. 


._..-_ 




































, — — , 




""^ 


Pt« ROOM HI 


"^"^ WO CAM ironjD ^ 


" ■-■■>~— -J!l!l 




— '— |— '— |— ■— 




. 1 , 1 V 






uuu. 








T.l>..n.«te»iM 






T«.l..-.r— !«-«-•- 






caasftK~ 






















■~-'' 



Tig. 60. Blank Report for Evaporated Milk. 



170 Standardizing EvAroRATED Milk 

HOW TO GET THE WEIGHT OF THE FINISHED BATCH OF 
EVAPORATED MILK. 

Ascertain the weight of fresh milk in the batch, and the weight 
of the finished product. The latter can be obtained in several 
ways, as follows: 

(A.) By weighing the entire batch in a drop tank near the 
pan. This is the most exact method of all. 

(B.) By means of a graduated brass bar or rod at the storage 
tank. This method is open to many variations, particularly if 
the tank surface is extensive. Variations in the concentration 
will also obviously affect the weight of any given volume, and may 
therefore cause considerable variation in the weight. The bar 
should be graduated by weighing definite successive portions of 
milk into the tank, and marking upon the bar the number of 
pounds corresponding to that in the tank at the given level. 

(C.) From the condensation. This method involves collect- 
ing an accurate com.posite sample of the raw milk that goes to 
make up the batch, and testing the same for T. S. If cream or 
skim-milk are added for standardizing, the T. S. test of the same 
should be ascertained, and the average T. S. test of the entire 
batch should be calculated. In turn when the finished product 
comes from the pan, this is to be tested for T. S., and the weight 
of condensed product obtained as indicated by the following 
example : 

Lbs. of fresh milk in the batch =6800 

Lbs. of cream used in standardizing = 40 



Lbs. total of all raw products =6840 

T. S. test of the fresh milk = 12.01% 

T. S. test of the cream =49.28% 
Average T. S. test of the mixed milk and cream = 12.23% 

T. S. test of the finished product = 26.50% 
26.50-^12.23 = 2.167, or the condensation. 

6840—2.167 = 3156, the lbs. of evaporated milk which the 
batch contains. 

By means of the Green Gauge, which automatically indicates 
the weight of milk in tanks. 



Green Gauge 



171 



The Green Gauge may be attached to any tank used for hold- 
ing fresh milk, condensed milk or any other liquid product. 

The mercury column in the gauge rises and falls as the milk 
in the tank rises and falls. The scale back of the mercury col- 
umn is calibrated to fit the particular tank to which it is attached 
so that when the mercury column stops opposite a number or 
graduation it indicates accurately the number of pounds of milk 
in the tank. The calibrating is usually done by dumping into the 
tank carefully weighed quantities of water and marking the 
lieight to which the mercury column rises. In this way an ac- 
curate calibration is obtained. 

The Green Gauge operates on the hydrostatic mercuric princi- 
ple. The air trap is connected to the tank outlet by 1" Sanitary 
Tubing. When filling tank the pet cock at bottom of air trap is 
opened until a few drops of milk flow out. The pet cock is then 
closed sealing a pocket of air in the air trap. The air trap is 
connected to the mercury gauge by a 1/8" copper tube. The 
weight of the milk in the tank is exerted on the air in the air 
trap and in turn on the mercury column in the gauge on the wall. 

This Green Gauge is a very convenient appliance for use in 
any liquid, as it practically places the tank to which it is attached 
on scales. 




Fig-. 61. Green Gaugre. 

HOW TO CALCULATE THE POINT AT WHICH TO STRIKE THE 
BATCH IN THE PAN. 

The striking point at the vacuum pan requires very careful 
watching, in order that the product from the pan may be as near 
the standard desired as possible. Evaporated milk of a given 
composition and temperature has a definite specific gravity. As 



172 



Standardizing Evaporated Mii,k 



a starting point it is necessary to know the specific gravity under 
certain temperature conditions of the product which it is desired 
to manufacture. 

The two following tables give the specific gravity of evapo- 
rated milk of the two compositions mentioned above at different 
temperatures, and expressed in different specific gravity scales. 

TABLE 26. 

Specific gravity of evaporated milk testing 7.80 per cent fat, and 25.50 per 
cent total solids compared with water at 60° F. Samples furnished by Na- 
tional Dairy Co Specific gravity determinations made by J. A. Cross and 
H. J. Liedel. 





Specific Gravity 


Tempera- 
ture 
°F. 


Specific Gravity 


Tempera- 
ture 
°F. 


Specific 
Gravity 
Degrees 


Baume 
Degrees 


Twaddell 
Degrees 


Specific 
Gravity 
Degrees 


Baume 
Degrees 


Twaddell 
Degrees 


40 

60 

80 

100 


1.0702 
1.0662 
1 . 0625 
1.0572 


9.51 
9.00 

8.52 
7.83 


14.04 
13.24 
12.50 
11.44 


110 
120 
130 
140 


1.0546 
1.0518 
1 . 0490 
1 0457 


7.51 
7.14 
6.78 
6.35 


10.92 

10.36 

9.80 

9 14 



TABLE 27. 

Specific gravity of evaporated milk testing 8.00 per cent fat, and 26.15 
per cent total solids; compared with water at 60" F. Samples furnished by 
National Dairy Co. Specific gravity determinations made by J. A. Cross 
and H. J. Liedel. 





Specific Gravity 


Tempera- 
ture 
° F. 


Specific Gravity 


Tempera- 
ture 
°F. 


Specific 
Gravity 
Degrees 


Baume 
Degrees 


Twaddell 
Degrees 


Specific 
Gravity 
Degrees 


Baume 
Degrees 


Twaddell 
Degrees 


40 

60 

80 

100 


1.0718 
1 . 0679 
1 . 0638 
1.0588 


9.71 
9.22 
8.70 
8.05 


14.36 
13.58 
12.76 
11.76 


110 
120 
130 
140 


1.0559 
1 . 0533 
1.0505 
1.0472 


7.67 
7.35 
6.97 
6.53 


11.18 

10.66 

10.10 

9.44 



Specific Gravity 



173 



The specific gravity at temperatures between the extremes given 
in the above tables, and at temperatures not given in the tables 
can be readily ascertained by referring to the graph included 
in this chapter, and which relates to the specific gravity of evapo- 
rated milk at various temperatures and of different compositions, 
but of a constant ratio between the fat and the total solids. 

THE RELATION BETWEEN THE TEMPERATURE AND SPECIFIC 
GRAVITY IN EVAPORATED MILK. 

In the case of evaporated milk, testing either 7.8* per cent fat 
and 25.50 per cent T. S., or 8.00 per cent fat and 26.15 per cent 
T. S., the relation between temperature and specific gravity is 
nearly alike. This is indicated in Table 28. 



TABLE 28. 
Unit Relation of Temperature to Specific Gravity in Evapoiated Milk. 





Decrease in 
Degree F. 


Specific Gravity for Each 
Increase in Temperature 


Temperature Range 


Specific 
Gravity 


Baume 


Twaddell 


40° to 80° F 

80° to 110° F 

110° to 140° F 


.00020 
. 00026 
.00029 


.025 
.034 
.039 


.040 
.053 
.058 



Important use of the above relation can be made when striking 
the pan. If the milk should have a temperature either higher or 
lower than the standard desired, at the time of making the specific 
gravity test, the reading can be reduced to the standard desired 
by a simple calculation. 

Example A: Baume reading at 135° F. is 6.57. What is the 
Baume reading at 130° F.? 

135 — 130—5, degrees F. over the standard desired. 
.039X5=.195, degrees Baume to be added to reading made at 

135° F. 
6.57+.195=6.77, the Baume reading reduced to 130° F. 

Example B : Baume reading at 120° F. is 7.14. What is the 
Baume reading at 130° F.? 



174 Standardizing Evaporated Milk 

130 — 120^10, degrees ¥. under the standard desired. 
.039X10=. 39, degrees Baume to be subtracted from reading 
made at 120° F. 

RELATION BETWEEN SPECIFIC GRAVITY AND COMPOSITION 
IN EVAPORATED MILK. 

When the hold-over system is used in the manufacture of evapo- 
rated milk, it is most desirable to make a preliminary test for fat 
or T. S., usually the test for one constituent being sufficient. This 
test should be timed so that the result is available before the milk 
for the last pan batch is all out of the hot wells. It is then pos- 
sible to change the striking point upon the last pan batch so that 
the test of the milk in the hold-over batch will be much closer to 
the desired standard than is usually possible where this practice is 
not followed. The great advantage is the fact that the water to 
be added can be reduced to a minimum. 

The relation between the composition and the specific gravity 
of evaporated milk in which the fat and the S. N. F. are in the 
ratio of 8.00 to 18.15, is indicated in Table 29. 

From the following table it is ascertained that a difference of 
.10^ Baume is equal to about .30 per cent of total solids in the 
case of evaporated milk of the composition indicated. Upon the 
specific gravity scale each .01 degree is equal to about .36 per cent 
total solids, and upon the Twaddell scale each .10 degrees is equal 
to about .18 per cent total solids. This information is of large 
practical value in fixing the striking point of the last pan batch 
used to make up a hold-over batch. 

Example: The fresh milk that makes up a hold-over batch 
totals 60,000 pounds. This is condensed in six pan batches of 
10,000 pounds each. The T. S. test of the first five batches, or, iv 
other words, the test of the condensed product obtained from 
50,000 pounds of whole milk was 26.75 per cent, and the total 
weight of the product 22,820 pounds. The test desired was 26.40 
per cent. Therefore 22,820 x .35 per cent equals 79.87 pounds of 
T. S. that are overcondensed. The last pan batch should yield 
about 5,000 pounds of condensed product testing 26.40 per cent 
T. S. Since a drop of .10 degees Baume would make a correspond- 
ing drop of .30 per cent in T. S. in this example each .10 degree 



Specific Gravity 



175 



TABLE 29. 
Relation Between Specific Gravity and Composition in Evaporated Milk. 







wad- 
dell 


■* 


1 


00 


GO 


Q 


o 


CD 


CO 






Tt< 


Hh »0 


CO 


o 


CM 


CO 


lO 






C5 


d GO 


t- 


t^ 


CO 


iO 


■* 




o o 

o o 


^ 1 


1 




1 




1 








s 

o3 


fO 




o 


o 


lO 


00 


CM 




CO 


CD "^ 




05 


CO 


CO 


CM 

CO 




T)< CD 


CQ 




1 








] 






1-H 




1 


1 














« >i 


(M 


t^ \ Oi \ 


Th 


o 


o 


00 


00 






=S.-S 


t^ 


12 1 <N 


o> 


lO 


T-H 


CO 


CM 








Tf 


'-f 


Tt< 


CO 


CO 


CO 


CM 


CM 








o 


o 


o 


o 


o 


o 


o 


o 








I— 1 


" 1 


1-H 


1— ( 


T-H 


'-' 


1— ( 


1-H 






73^ 
Pt3 


CD 


CO ■ O 1 


CM 


o 


CM 


o 


CO 






CD 


CO 


00 


o 


C^l 


CO 


CO 


00 






d 


,_; 


a> 


d 


00 


t^ 


d 


lO 




fo 


H 




'"' 




1 












6 


LO 


^ ' '^ 


l:^ 


C^l 


CM 


"* 


CO 




CO 


^ t- 


CM 


l^ 


1-H 


CD 


T-H 




O 


s 


















O O 


e3 


t^ 


w ^ 


CO 


lO 


lO 


-* 


tJ< 


< 


(N CD 
1— 1 


pq 














=^ >> 


CO 


00 1 o 


1— 1 


o 


CO 


o 


CO 


t. 




^.S 


CO 


--< ' Oi 


lO 


T-H 


CO 


CO 


03 




"B"> 


IQ 


'O rtl 


'^ 


■<* 


CO 


CO 


CM 




o 


O o 


o 


o 


o 


c 


o 


> 






T™l 


1 


-< 


-^' 


-^ 


'-' 


^ 


o 








1 
















i=3 

&T3 


CO 


^ 00 


CD 


00 


CM 


CO 


CM 






t^ 


'^ 


d 


O 

d 


05 


CO 

00 




d 


o 




H 


1— 1 


^ 1 




T-( 










N 




Q O 




















A. 


4J 

s 

03 


lO 


1^ 


»o 


lO 


■CO 


00 


CM 




o 

00 


CO ,-< 

00 T 


CD 


CO 
CO 




CM 






O CO 


m 


















w >-> 


GO 


O-l Tfl 


CO 


03 


CO 


GO 


CO 








GO 


t^ T^ 


O 


lO 


1-H 


r- 


CO 






lO 


'O lO 


lO 


■*! 


-# 


CO 


CO 






o 


9 o 


o 


o 


o 


c 


o 








^__, 


'"' I— ( 


1-H 


1-H 


1-H 


1-H 


1— 1 








1 
















1 

&-0 


c» 


-H CO 

^ 1 '^ 


CM 


o 


CM 


CO 


CI 






LC • 


00 


o 


Oi 


^ 


CM 






CO 


CO 1 CM 


,-, 


^ 


d 


d 


00 




Em 
°o h 


H 




1— { 1 1—1 


1— 1 


'"' 










a; 

s 

D 
03 


CM 


o ^ 

a: 1 <^ 


o 


«0 


CD 


lO 


CO 






1— ( 

00 




00 

CO 


CO 
d 






CO CO 


W 




1 
















05 


Ol 00 


,_! 


o 


CD 


00 


T-H 






r^ 


CO Ol 


Oi 


lO 


Cft 


lO 


1-H 






CD 


CO CD 


lO 


lO 


I* 


^ 


'^f 






CD f3 


O 


O o 


o 


o 


o 


o 


o 








'-' 


■—I .-( 


I-H 


1-H 


I-H 


1-H 


T-H 


O tC 


m 


C/5 


CO 


CK 


02 


CO 


aj 


W2 


-ti 




-kJ 


-u 


-1-i 


-4^ 


•+J 


■4^ 




H S 


^ <^ 


H "S 


C^ «^-H 


r, 03 


H ^ 


H <^ 


H «S 


a^ 


ic o 


o 


CM O 


CO o 


lO o 


1-H O 


00 o 


TJH O 


^ o 


■o o 


lO lO 


CD O 


CM lO 


CO o 


05 >C 


CO O 


as 
-pa. 




. 00 














CO 00 


■O 1-^ 


TjH t>- 


CM t-- 


^ d 


Oi CD 


t^ lO 


CO >o 


CM 


CM ' 


CM 


CM 


C^l 


rH 


1-H 


I-H 




U 





















176 Standardizing Evaporated Milk 

Baurae would correct for 15.00 pounds of T. S. Since the over- 
condensation amounts to 79.87 pounds, dividing this amount by 
15.00 gives 5.3 or the number of .10 degees Baume necessary to 
deduct from the normal striking point of the last batch. 

The graph under Fig. 62 shows the relation between tempera- 
ture, specific gravity and composition in the case of evaporated 
milk in which tlie ratio between S. N. F. and fat is as 1 is to .4407, 
or T. S. to fat as 1 is to .3059. 

The range of composition is from 5.00 per cent fat and 16.34 
per cent T. S. to 8.00 per cent fat and 26.15 per cent T. S. 

Several practical uses can be made of this graph as shown by 
the following examples : 

(a.) Example: What is the specific gravity of evaporated 
milk testing 7.80 per cent fat and 25.50 per cent T. S. at 50° F.? 
Answer. 1.0738. 

(b.) Example: What is the composition of evaporated milk 
in which the ratio between the S. N. F. and fat is as 1 to .4407? 
Baume reading 6.53. Temperature 140° F. Answer : 8.00 per 
cent fat and 26.15 per cent T. S. 

(c.) Example: The specific gravity test of evaporated milk 
containing 7.50 per cent fat and 24.52 per cent T. S. at 140° F. is 
.596 Baume. What is the Baume reading at 120° F. ? Answer: 
6.77° Baume. 

HOW TO CALCULATE THE BAUME READING OF A CONDENSED 
MILK PRODUCT FOR ANY DESIRED CONDENSATION, 
IF THE BAUME TEST AT ANY OTHER CON- 
DENSATION IS KNOWN. • 

This method of calculation wrs devised by J. A. Cross. 

Calculate the weight in grams of 100 c. c. of the product of 
which the specific gravity and the composition are known. Also 
calculate the amount of water to be evaporated in order to pro- 
duce the desired concentration, and the volume occupied by the 
water to be evaporated. Then deduct the weight and the volume 
of the desired product from that of the known product. Obtain 
the specific gravity from these calculations, and in turn look up 
the corresponding Baume reading. 

Example : The Baurae test of evaporated milk containing 5.0 
per cent fat and 16.35 per cent T. S. is 3.22° at 140° F, What will 



Specific Gravity 



177 



Key to Fig. 62 




SPECIF/C GRAVITY /N DEGREES BAUME 



Pig-. 62. Relation between temperature, specific gravity and composition 
in the case of evaporated milk in -which the ratio between S. N. F. and fat 
is as 1 to .4407. Results obtained by J. A. Cross and H. J. Iiiedel. 

the Baume test be in the case of evaporated milk testing 8.0 per 
cent fat and 26.15 per cent T. S. at 140° F. ? 
3.22° B. = 1.0226 specific gravity. 
100 c. c. = 102.26 grams. 

To raise the test from 5.0 per cent to 8.0 per cent requires the 
evaporation of 37.5 per cent water. 

•100x5 
100 — I I i = 37.50 



V-<^)\ 



100 X 8 
102.26X37.50—38.34, grams water to be evaporated. 
The specific volume of water at 140° F. is .9834. 
38.34-^9834=39, c. c. of water to be evaporated. 



178 



vStandardizing EvAroRATED Milk 



100 — 39=61, c. c. in product desired. 

102.26 — 38.34^63.92, grams in product desired. 

63.92^61=1.0473,, specific gravity or 6.53° B. 

HOW TO STRIKE THE PAN BATCH. 

Several methods are available for striking the batch at the 
pan. These all depend upon obtaining the specific gravity of the 
condensed product. Two principal methods of sampling at the 
pan are recommended. One is by means of a sampling device at- 
tached to the waist of the pan. This is illustrated under Fig. 63. 
The second is attached to the outlet of the pan, and is illustrated 
under Fig. 64, It is sometimes possible to obtain the specific 
gravity by placing the hydrometer directly into the tube of the 




BOTTOM OF VACUUM PAN 



MILK DRAW-OFF COCK 




TO DROP TANK 



Pigf. 



63. Fan Striker for Attachingr 
to Waist of Pan. 



Figf. 64. Fan Striker for Attaching' 
to Outlet of Pan. 



device attached to the waist of the pan. The most common prac- 
tice is to draw the sample into a hydrometer jar and to place the 
hydrometer directly therein. The hydrometer jar that is recom- 



Holding Tanp: 



179 



' juiiiiimiiiifo - 




Pig-. 65. 

Hydrometer 

Cylinder. 



mended is illustrated under 
Fig. 65. Hydrometers with sev- 
eral scales are used. The one 
most commonly used has a 
range of 5 to 12 graduated into 
tenths upon the Baume scale. 
This corresponds to 1.0357 to 
1.1154 upon the specific gravity 
scale. This type of hydrometer 
is illustrated under Fig. 66. 



Fig-. 66. 

Baume 

Hydrom^eter. 



HOLDING TANKS FOR STANDARDIZING EVAPORATED MILK. 

Two methods of handling the condensed product are possible, 
namely, the multibatch and the hold-over method. In the first 
method each pan batch is handled as one complete unit. In the 
hold-over method all, or a part of the total pan batches making up 
the day's run are mixed in one large tank. If the product is 
canned the same day that it is condensed, artificial refrigeration 
is not necessary. If the product is held over night under either 
method, it must be cooled to about 40^^ F. The multibach method 
is applicable to small plants, handling under 10,000 pounds of 
milk daily, while the hold-over method is applicable to all evapo- 
rated milk plants handling more than this amount of milk. 

In Fig. 67 is illustrated a jacketed copper tank very suitable to 
the use of small plants. Either brine or water can be used as 
the cooling medium. In Fig. 68 is illustrated a glass enamelled 
tank. These can be furnished in sizes to suit the needs of the 
plant, either in the horizontal or vertical type. For small tanks 
single propeller blade agitators, as illustrated, are very satisfac- 
tory for obtaining a proper mixture. For large horizontal tanks 
it is recommended that two propeller agitators be used — one in 
each end. 



180 



Standardizing Evaporated Milk 




Tig. 67. Jacketed Copper Tank. 



The hold-over tanks should be placed either in a refrigerated 
room or they should be insulated with not less than four inches 
of the best cork board and finished with two coats of cement plas- 
ter, the last coat being brought to a smooth, float finish. Tanks 
must be fitted with suitable thermometers, so the temperature of 
the milk can be properly observed at all times. 

THE USE OF TABLES IN SHORTENING CALCULATIONS. 

Much time can be saved by the use of properly prepared tables 
covering the products Avhich it is desired to manufacture. This 
cliapter contains two tables applicable to the manufacture of 
evaporated milk upon the double basis of 7.80 per cent of fat and 
25.50 per cent of T. S., and 8.00 per cent fat and 26.15 per cent 
of T. S. 

Table 30 gives the per cent of fat and the per cent of S. N. F. 
in the proper ratio one to the other for standardizing both of the 
above products as shown in Table 25. The ratios between S. N. F. 
and fat in the two products are so near alike that the same values 
can be applied to solve problems involving either product. The 



Tables for Shortkning CaIvCulations 



181 







■ 


B 




^1 


mKtMi 



table has a range 
from .01 to 4.99 per 
cent of fat and from 
.02 to 11.32 per cent 

of S. N. F. 

The table can be 
used in several 
ways, as follows : 

(1.) To deter- 
mine the per cent of 
S. N. F. required to 
standardize the fat 
in any given skim- 
milk. Example: 
Skim-milk tests .16 
per cent fat. Refer- 
ence to the table 
shows that .36 per 
cent of S. N. F. is re- 
quired to standardize 
.16 per cent of fat. 
(2.) To determine the per cent of fat required to standard- 
ize the S. N. F. in any given cream. Example : Cream tests 7.10 
per cent of S. N. F. Reference to the table shows that 3.13 per 
cent of fat is required to standardize 7.10 per cent of S. N. F. 

(3.) To determine the per cent of fat required to standardize 
the S. N. F. in any given whole milk or vice versa. Example : 
Whole milk tests 4,00 per cent of fat. Reference to the table shows 
that 9.08 per cent of S. N. F. are required to standardize 4.00 per 
cent of fat. 

The same results as given in the table can be obtained by multi- 
plying the per cent of fat by .4407, or by dividing the per cent 
of S. N. F. by .4407, but the use of the table dispenses with these 
long calculations and helps to prevent errors. This table is in- 
tended primarily for use when standardizing before condens- 
ing, although it can sometimes be applied in part upon some prob- 
lems covering standardization after condensing. This applies par- 
ticularly to the use of cream as in the example given above. 



Fig". 68. Glass Enameled Tank. 

Courtesy of the Pfaudler Co. 



182 



Standardizing Evaporated Mii,k 
TABLE 30. 



Per cents fat and S. N. F. in the proper ratio to standardize evaporated 
milk upon the basis of either 7.80 per cent of fat and 25.50 per cent of T. S. 
or 8.00 per cent of fat and 26.15 per cent of T. S. Ratio being 1 S. N. F. to 
.4407 fat. 



Per Cent 
Fat 


Per Cent 

S. N. F. 


Per Cent 
Fat 


Per Cent 

S. N. F. 


Per Cent 
Fat 


Per Cent 

S. N. F. 


Per Cent 
Fat 


Per Cent 

S. N. F. 


.01 


.02 


.40 


.91 


.78 


1.77 


1.17 


2.65 


.02 


.05 


.41 


.93 


.79 


1.79 


1.18 


2.68 


.03 


.07 


.42 


.95 


.80 


1.82 


1.19 


2.70 


.04 


.09 


.43 


.98 


.81 


1.84 


1.20 


2.72 


.05 


.11 


.44 


1.00 


.82 


1.86 


1.21 


2.75 


.06 


.14 


.45 


1.02 


.83 


1.88 


1.22 


2.77 


.07 


.16 


.46 


1.04 


.84 


1.91 


1.23 


2.79 


.08 


. .18 


.47 


1.07 


.85 


1.93 


1.21 


2.81 


.09 


.20 


.48 


1.09 


.86 


1.95 


1.25 


2.84 


.10 


.23 


.49 


1.11 


.87 


1.97 


1.26 


2.86 


.11 


.25 


.50 


1.13 


.88 


2.00 


1.27 


2.88 


.12 


.27 


.51 


1.16 


.89 


2.02 


1.28 


2.90 


.13 


.29 


.52 


1.18 


.90 


2.04 


1.29 


2.93 


.14 


.32 


.53 


1.20 


.91 


2.06 


1.30 


2.95 


.15 


.34 


.54 


1.23 


.92 


2.09 


1.31 


2.97 


.16 


.36 


.55 


1.25 


.93 


2.11 


1.32 


3.00 


.17 


.39 


.56 


1.27 


.94 


2.13 ■ 


1.33 


3.02 


.18 


.41 


.57 


1.29 


.95 


2.16 


1.34 


3.04 


.19 


.43 


.58 


1.32 


.96 


2.18 


1 . 35 


3.06 


.20 


.45 


.59 


1.34 


.97 


2.20 


1.36 


3.09 


.21 


.48 


.60 


1.36 


.98 


2.22 


1.37 


3.11 


.22 


.50 


.61 


1.38 


.99 


2.25 


1.38 


3.13 


.23 


.52 


.62 


1.41 


1.00 


2.27 


1.39 


3.15 


.24 


.54 


.63 


1.43 


1.01 


2.29 


1.40 


3.18 


.25 


.57 


.64 


1.45 


1.02 


2.31 


1.41 


3.20 


.26 


.59 


.65 


1.47 


1.03 


2.34 


1.42 


3.22 


.27 


.61 


.66 


1.50 


1.04 


2.36 


1.43 


3.24 


.28 


.64 


.67 


1.52 


1.05 


2.38 


1.44 


3.27 


.29 


.66 


fiS 


1 "14 


1.06 


2.41 


1.45 


3.29 


.30 


.68 


.69 
.70 
.71 


i. . Ot: 

1.57 
1.59 
1.61 


1.07 


2.43 


1.46 


3.31 


.31 


.70 


1.08 


2.45 


1.47 


3.34 


.32 
.33 


.73 
.75 


1.09 
1.10 


2.47 
2.50 


1.48 
1.49 


3.36 
3.38 


.34 


.77 


.72 


1.63 


1.11 


2.52 


1.50 


3.40 


.35 


.79 


.73 


1.66 


1.12 


2.54 


1.51 


3.43 


.36 


.82 


.74 


1.68 


1.13 


2.56 


1.52 


3.45 


.37 


.84 


.75 


1.70 


1.14 


2.59 


1.53 


3.47 


.38 


.86 


.76 


1.72 


1.15 


2.61 


1.54 


3.49 


.39 


.88 


.77 


1.75 


1.16 


2.63 


1.55 


3.52 



Tables for Shortening Calculations 

TABLE 30 (Continued). 



183 



Per Cent 
Fat 


Per Cent 

S. N. F. 


Per Cent 
Fat 


Per Cent 

S. N. F. 


Per Cent 
Fat 


Per Cent 

S. N. F. 


Per Cent 
Fat 


Per Cent 

S. N. F- 


1.56 


3.54 


2.00 


4.54 


2.44 


5.54 


2.88 


6.54 


1.57 


3.56 


2.01 


4.56 


2.45 


5.56 


2.89 


6.56 


1.58 


3.59 


2.02 


4.58 


2.46 


5.58 


2.90 


6.58 


1.59 


3.61 


2.03 


4.61 


2.47 


5.60 


2.91 


6.60 


1.60 


3.63 


2.04 


4.63 


2.48 


5.63 


2.92 


6.63 


1.61 


3.65 


2.05 


4.65 


2.49 


5.65 


2.93 


6.65 


1.62 


3.68 


2.06 


4.67 


2.50 


5.67 


2.94 


6.67 


1.63 


3.70 


2.07 


4.70 


2.51 


5.70 


2.95 


6.69 


1.64 


3.72 


2.08 


4.72 


2.52 


5.72 


2.96 


6.72 


1.65 


3.74 


2.09 


4.74 


2.53 


5.74 


2.97 


6.74 


1.66 


3.77 


2.10 


4.77 


2,54 


5.76 


2.98 


6.76 


1.67 


3.79 


2.11 


4.79 


2.55 


5.79 


2.99 


6.78 


1.68 


3.80 


2.12 


4.81 


2.56 


5.81 


3.00 


6.81 


1.69 


3.83 


2.13 


4.83 


2.57 


5.83 


3.01 


6.83 


1.70 


3.86 


2.14 


4.86 


2.58 


5.85 


3.02 


6.85 


1.71 


3.88 


2.15 


4.88 


2.59 


5.88 


3.03 


6.88 


1.72 


3.90 


2.16 


4.90 


2.60 


5.90 


3.04 


6.90 


1.73 


3.93 


2.17 


4.92 


2.61 


5.92 


3.05 


6.92 


1.74 


3.95 


2.18 


4.95 


2.62 


5.95 


3.06 


6.94 


1.75 


3.97 


2.19 


4.97 


2.63 


5.97 


3.07 


6.97 


1.76 


3.99 


2.20 


4.99 


2.64 


5.99 


3.08 


6.99 


1.77 


4.02 


2.21 


5.01 


2.65 


6.01 


3.09 


7.01 


1.78 


4.04 


2.22 


5.04 


2.66 


6.04 


3.10 


7.03 


1.79 


4.06 


2.23 


5.06 


2.67 


6.06 


3.11 


7.06 


1.80 


4.08 


2.24 


5.08 


2.68 


6.08 


3.12 


7.08 


1.81 


4.11 


2.25 


5.11 


2.69 


6.10 


3.13 


7.10 


1.82 


4.13 


2.26 


5.13 


2.70 


6.13 


3.14 


7.13 


1.83 


4.15 


2.27 


5.15 


2.71 


6.15 


3.15 


7.15 


1.84 


4.18 


2.28 


5.17 


2.72 


6.17 


3.16 


7.17 


1.85 


4.20 


2.29 


5.20 


2.73 


6.19 


3.17 


7.19 


1.86 


4.22 


2.30 


5.22 


2.74 


6.22 


. 3.18 


7.22 


1.87 


4.24 


2.31 


5.24 


2.75 


6.24 


3.19 


7.24 


1.88 


4.27 


2.32 


5.26 


2.76 


6.26 


3.20 


7.26 


1.89 


4.29 


2.33 


5.29 


2.77 


6.29 


3.21 


7.28 


1.90 


4.31 


2.34 


5.31 


2.78 


6.31 


3.22 


7.31 


1.91 


4.33 


2.35 


5.33 


2.79 


6.33 


3.23 


7.33 


1.92 


4.36 


2.. 36 


5.36 


2.80 


6.35 


3.24 


7.35 


1.93 


4.38 


2.37 


5.38 


2.81 


6.38 


3.25 


7.37 


1.94 


4.40 


2.. 38 


5.40 


2.82 


6.41 


3.26 


7.40 


1.95 


4.42 


2.39 


5.42 


2.83 


6.42 


3.27 


7.42 


1.96 


4.45 


2.40 


5.44 


2.84 


6.44 


3.28 


7.44 


1.97 


4.47 


2.41 


5.47 


2.85 


6.47 


3.29 


7.47 


1.98 


4.49 


2.42 


5.49 


2.86 


6.49 


3.30 


7.49 


1.99 


4.52 


2.43 


5.51 


2.87 


6.51 


3.31 


7.51 



18^ 



Standardizing Evaporated Milk 
TABLE 30 (Continued). 



Per Cent 
Fat 


Per Cent 

S. N. F. 


Per Cent 
Fat 


Per Cent 

S. N. F. 


Per Cent 
Fat 


Per Cent 

S. N. F. 


Per Cent 
Fat 


Per Cent 
S. N. F. 


3.32 


7.53 


3.74 


8.49 


4.16 


9.44 


4.58 


10.39 


3.33 


7.56 


3.75 


8.51 


4.17 


9.46 


4.59 


10.42 


3.34 


7.58 


3.76 


8.53 


4.18 


9.49 


4.60 


10.44 


3.35 


7.60 


3.77 


8.55 


4.19 


9.51 


4.61 


10.46 


3.36 


7.62 


3.78 


8.58 


4.20 


9.53 


4.62 


10.48 


3.37 


7.65 


3.79 


8.60 


4,21 


9.56 


4.63 


10.51 


3.38 


7.67 


3.80 


8.62 


4.22 


9.58 


4.64 


10.53 


3.39 


7.69 


3.81 


8.65 


4.23 


9.60 


4.65 


10.55 


3.40 


7.72 


3.82 


8.67 


4.24 


9.62 


4.66 


10.57 


3.41 


7.74 


3.83 


8.69 


4.25 


9.64 


4.67 


10.60 


3.42 


7.76 


3.84 


8.71 


4.26 


9.67 


4.68 


10.62 


3.43 


7.78 


3.85 


8.74 


4.27 


9.69 


4.69 


10.64 


3.44 


7.81 


3.86 


8.76 


4.28 


9.71 


4.70 


10.67 


3.45 


8.83 


3.87 


8.78 


4.29 


9.73 


4.71 


10.69 


3.46 


7.85 


3.88 


8.80 


4.30 


9.76 


4.72 


10.71 


3.47 


7.87 


3.89 


8.83 


4.31 


9.78 


4.73 


10.73 


3.48 


7.90 


3.90 


8.85 


4.32 


9.80 


4.74 


10.76 


3.49 


7.92 


3.91 


8.87 


4.33 


9.83 


4.75 


10.78 


3.50 


7.94 


3.92 


8.90 


4.34 


8.85 


4.76 


10.80 


3.51 


7.96 


3.93 


8.92 


4.35 


9.87 


4.77 


10.82 


3.52 


7.99 


3.94 


8.94 


4.36 


9.89 


4.78 


10.85 


3.53 


7.01 


3.95 


8.96 


4.37 


9.92 


4.79 


10.86 


3.54 


8.03 


3.96 


8.99 


4.38 


9.94 


4.80 


10.89 


3.55 


8.06 


3.97 


9.01 


4.39 


9.96 


4.81 


10.91 


3.56 


8.08 


3.98 


9.03 


4.40 


9.98 


4.82 


10.94 


3.57 


8.10 


3.99 


9.05 


4.41 


10.01 


4.83 


10.96 


3.58 


8.12 


4.00 


9.08 


4.42 


10.13 


4.84 


10.98 


3.59 


8.15 


4.01 


9.10 


4.43 


10.05 


4.85 


11.01 


3.60 


8.17 


4.02 


9.12 


4.44 


10.08 


4.86 


11.03 


3.61 


8.19 


4.03 


9.14 


4.45 


10.10 


4.87 


11.05 


3.62 


8.21 


4.04 


9.17 


4.46 


10.12 


4.88 


11.07 


3.63 


8.24 


4.05 


9.19 


4.47 


10.14 


4.89 


11.10 


3.64 


8.26 


5.06 


9.21 


4.48 


10.17 


4.90 


11.12 


3.65 


8.28 


4.07 


9.24 


4.49 


10.19 


4.91 


11.14 


3.66 


8.31 


4.08 


9.26 


4.50 


10.21 


4.92 


11.16 


3.67 


8.33 


4.09 


9.28 


4.51 


10.23 


4.93 


11.19 


3.68 


8.35 


4.10 


9.30 


4.52 


10.26 


4.94 


11.21 


3.69 


8.37 


4.11 


9.33 


4.53 


10.28 


4.95 


11.23 


3.70 


8.40 


4.12 


9.35 


4.54 


10.30 


4.96 


11.26 


3.71 


8.42 


4.13 


9.37 


4.55 


10.32 


4.97 


11.28 


3.72 


8.44 


4.14 


9.39 


4.56 


10.35 


4.98 


11.30 


3.73 


8.46 


4.15 


9.42 


4.57 


10.37 







Tablks for Shortening Calcul.xtions 



18: 



TABLE 31. 

Percentages of fat, S. N. F. and T. S. in product after condensing, all in 
the proper ratio to standardize upon the basis of either 7.80 per cent of fat and 
25.50 per cent of T. S., or 8.00 per cent of fat and 26.15 per cent of T. S. 
Ratio in either case being 1 S. N. F. to .4407 of fat. Also the factor of over- 
condensation fiom 7.80 to 9.00 per cent, and from 8.00 to 9.00 per cent of 
fat. 





S. N. F. 


T. S. 


Over- 
condensation 


Fat 


S. N. F. 


T. S. 


OVEB- 
CONDENSATION 


Fat 


7.80- 

25.50 

Standard 


8.00 

26.15 

Standard 


7.80- 

25,50 

Standard 


8.00- 

26.15 

Standard 


7.00 


15.88 
15.89 
15.90 
15.91 
15.92 
15.93 
15.94 
15.95 
15.96 
15.97 
15.98 
15.99 
16.00 
16.01 
16.02 
16.03 
16.04 
16.05 
16.06 
16.07 
16.08 
16.09 
16.10 
16.11 
16.12 
16.13 
16.14 
16.15 
16.16 
16.17 
16.18 
16.19 
16.20 
16.21 
16.22 


22.88 
22.89 
22.91 
22.92 
22.94 
22.95 
22.96 
22.98 
22.99 
23.01 
23.02 
23.04 
23.05 
23.07 
23.08 
23.09 
23.11 
23.12 
23.14 
23.15 
23.17 
23.18 
23.20 
23.21 
23.22 
23.24 
23.25 
23.27 
23.28 
23.30 
23.31 
23.32 
23.34 
23.35 
23,37 






7.15 
7.16 
7.16 
7.17 
7.17 
7.17 
7.18 
7.18 
7.19 
7.19 
7.20 
7.20 
7.21 
7.21 
7.21 
7.22 
7.22 
7.23 
7.24 
7.24 
7.25 
7.25 
7.25 
7.26 
7.26 
7.27 
7.27 
7.28 
7.28 
7.28 
7.29 
7.29 
7.30 
7.30 
7.31 


16.23 
16.24 
16.25 
16.26 
16.27 
16.28 
16.29 
16,30 
16.31 
16.32 
16.33 
16.34 
16.35 
16.36 
16.37 
16.38 
16.39 
16.40 
16.41 
16.42 
16.43 
16.44 
16.45 
16.46 
16.47 
16.48 
16.49 
16.50 
16.51 
16.52 
16.53 
16.54 
16.55 
16.56 
16.57 


23.38 
23.40 
23.41 
23.42 
23.44 
23.45 
23.47 
23.48 
23.50 
23.51 
23.53 
23.54 
23.56 
23.57 
23.58 
23.60 
23.61 
23.63 
23.64 
23.66 
23.67 
23.69 
23.70 
23.71 
23.73 
23.74 
23.76 
23.77 
23.79 
23.80 
23.81 
23.83 
23.84 
23.86 
23.87 






7.00 










7.01 










7.01 










7.02 










7.02 










7.02 










7.03 










7.03 










7.04 










7.04 










7.05 










7.05 










7.06 










7.06 










7.06 










7.07 










7.07 










7.08 










7.08 










7.09 










7.09 










7.10 










7.10 










7.10 










7.11 










7.11 










7 12 










7 12 










7.13 










7 13 










7 13 










7.14 










7.14 










7.15 











Standardizing Evaporated ^IiLi^ 

TABLE 31 (Continued). 




Tables i-'or Shortkninc Calculations 

TABLE 31 (Continued). 



187 





S. N. F. 


T. S. 


Over- 
condensation 


Fat 


S. N. F. 


T. S. 


Over- 
condensation 


Fat 


7.80- 

25.50 

Standard 


8.00- 

26.15 

Standard 


7.80- 

25.50 

Standard 


8.00 

26.15 

Standard 


7.67 


17.40 


25.07 






7.85 


17.82 


25.67 


.0066 




7.67 


17.41 
17.42 
17.43 
17.44 


25.08 
25.10 
25.11 
25.13 






7.86 
7.86 
7.87 
7.87 


17.83 
17.84 
17.85 
17.88 


25.69 
25.70 
25.72 
25.73 


.0074 
.0078 
.0086 
.0090 




7.68 








7.68 








7.69 








7.69 


17.45 
17.46 
17.47 
17.48 
17.49 
17.50 
17.51 


25.14 
25.15 
25.17 
25.18 
25.20 
25.21 
25.23 






7.88 
7.88 
7.88 
7.89 
7.89 
7.90 
7.90 


17.87 
17.86 
17.89 
17.90 
17.91 
17.92 
17.93 


25.75 
25.76 
25.77 
25.79 
25.80 
25.82 
25.83 


.0098 
.0101 
.0105 
.0113 
.0117 
.0125 
.0129 




7.69 








7.70 








7.70 








7.71 








7.71 








7.72 








7.72 


17.52 
17.53 
17.54 
17.55 
17.56 
17.57 
17.58 
17.59 
17.60 
17.61 
17.62 
17.63 
17.64 
17.65 
17.66 
17.67 
17.68 
17.69 
17.70 
17.71 


25.24 
25.26 
25.27 
25.28 
25.30 
25.31 
25.33 
25.34 
25.36 
25.37 
25.39 
25.40 
25.41 
25.43 
25.44 
25.46 
25.47 
25.49 
25.50 
25.61 






7.91 
7.91 
7.91 
7.92 
7.93 
7.93 
7.93 
7.94 
7.94 
7.95 
7.95 
7.95 
7.96 
7.96 
7.97 
7.97 
7.98 
7.98 
7.99 
7.99 


17.94 
17.95 
17.96 
17.97 
17.98 
17.99 
18.00 
18.01 
18.02 
18.03 
18.04 
18.05 
18.06 
18.07 
18.08 
18.09 
18.10 
18.11 
18.12 
18.13 


25.85 
25.86 
25.87 
25.89 
25.90 
25.92 
25.93 
25.95 
25.96 
25.98 
25.99 
26.00 
26.02 
26.03 
26.05 
26.06 
26.08 
26.09 
26.11 
26.12 


.0137 
.0141 
.0145 
.0152 
.0156 
.0164 
.0168 
.0176 
.0180 
.0188 
.0192 
.0196 
.0203 
.0207 
.0215 
.0219 
.0227 
.0231 
.0239 
.0243 




7.73 








7.73 








7.73 








7.74 








7.74 








7.75 








7.75 








7.76 








7.76 








7.77 








7.77 








7.77 








7.78 








7.78 








7.79 








7.79 








7.80 








7.80 








7.80 


.0004 






7.81 


17.72 


25.52 


.0007 




7.99 


18.14 


26.13 


.0246 




7.81 


17.73 


25.54 


.0015 




8.00 


18.15 


26.15 


.0254 




7.82 


17.74 


25.56 


.0023 




8.00 


18.16 


26.16 


.0258 


.0004 


7.82 


17.75 


25.57 


.0027 




8.01 


18.17 


26.18 


.0266 


.0008 


7.83 


17.76 


25.59 


.0035 




8.01 


18.18 


26.19 


.0270 


.0015 


7.83 


17.77 


25.60 


.0039 




8.02 


18.19 


26.21 


.0278 


.0023 


7.84 


17.78 


25.62 


.0047 




8.02 


18.20 


26.22 


.0282 


.0027 


7.84 


17.79 


25.63 


.0050 




8.03 


18.21 


26.24 


.0290 


.0034 


7.84 


17.80 


25.64 


.0054 




8.03 


18.22 


26.25 


.0294 


.0038 


7.85 


17.81 


25.66 


.0062 




8.03 


18.23 


26.26 


.0297 


.0042 



188 



Standardizing Evaporated Milk 
TABLE 31 (Continued). 





S. F. F. 


T. S. 


OVER- 
CONDEN8ATION- 


Fat 


S, N, F, 


T. S. 


Over- 
condensation 


Fat 


7.80- 

25 . .50 
Standard 


8.00- 

26.15 

Standard 


7.80- 
25 . 50 

Standard 


8.00- 

26.15 

Standard 


8.04 


18.24 


26.28 


.0305 


.0050 


8.22 


18.66 


26.88 


.0540 


.0279 


8.04 


18.25 


26.29 


.0309 


.0054 


8.23 


18,67 


26.90 


.0548 


.0287 


8.05 


18.26 


26.31 


.0317 


.0061 


8.23 


18,68 


26.91 


.0552 


.0291 


8.05 


18.27 


26.32 


.0321 


.0065 


8.24 


18.69 


26.23 


.0560 


,0298 


8.06 


18.28 


26.34 


.0329 


.0073 


8,24 


18,70 


26.94 


,0564 


,0302 


8.06 


18.29 


26.35 


.0333 


.0076 


8,25 


18.71 


26.96 


,0572 


,0310 


8.06 


18.30 


26.36 


.0337 


.0080 


8,25 


18.72 


26.97 


.0576 


,0314 


8.07 


18.31 


26.38 


.0344 


.0088 


8.25 


18.73 


26.98 


.0580 


.0317 


8.07 


18.32 


26.39 


.0348 


.0092 


8,26 


18.74 


27.00 


.0588 


,0325 


8.08 


18.33 


26.41 


.0356 


.0099 


8,26 


18.75 


27.01 


,0591 


.0329 


8.08 


18.34 


26.42 


.0360 


. 0103 


8,27 


18.76 


27.03 


.0599 


.0336 


8.09 


18.35 


26.44 


.0366 


,0111 


8,27 


18.77 


27.04 


.0603 


.0340 


8.09 


18.36 


26.45 


.0372 


.0115 


8,28 


18.78 


27.06 


,0611 


.0348 


8.10 


18.37 


26.47 


.0380 


,0122 


8.28 


18,79 


27.07 


,0615 


.0352 


8.10 


18.38 


26.48 


.0384 


.0126 


8,29 


18,80 


27.09 


.0623 


,0359 


8.10 


18.39 


26.49 


.0388 


,0130 


8.29 


18,81 


27,10 


.0627 


.0363 


8.11 


18.40 


26.51 


.0395 


.0133 


8,29 


18,82 


27,11 


.0631 


,0667 


8.11 


18.41 


26.52 


.0400 


,0141 


8.30 


18,83 


27 , 13 


.0338 


.0375 


8.12 


18.42 


26.54 


.0407 


.0149 


8.30 


18,84 


27,14 


.0642 


.0379 


8.12 


18.43 


26.55 


.0412 


.0153 


8,31. 


18,85 


27,16 


.0650 


.0386 


8.13 


18.44 


26.57 


.0417 


.0161 


8,31 


18,86 


27,17 


.0654 


.0390 


8.13 


18.45 


26.58 


.0423 


.0164 


8,32 


18,87 


27,19 


.0662 


.0398 


8.14 


18.46 


26.60 


.0431 


.0172 


8,32 


18.88 


27,20 


.0666 


.0402 


8.14 


18.47 


26.61 


.0435 


.0176 


8.32 


18.89 


27,21 


.0670 


.0407 


8.14 


18.48 


26.62 


.0439 


.0180 


8,33 


18.90 


27.23 


.0678 


.0413 


8.15 


18.49 


26.64 


.0446 


.0187 


8,33 


18.91 


27,24 


.0682 


,0417 


8.15 


18.50 


26.65 


.0450 


.0191 


8.34 


18.92 


27,26 


.0689 


.0424 


8.16 


18.51 


26.67 


.0458 


.0199 


8,34 


18.93 


27,27 


.0693 


.0428 


8.16 


18.52 


26.68 


.0462 


.0203 


8,35 


18.94 


27,29 


.0701 


, 0436 


8.17 


18.53 


26.70 


.0470 


.0210 


8,35 


18.95 


27,30 


.0705 


,0440 


8.17 


18.54 


26.71 


.0471 


.0214 


8.36 


18,96 


27,32 


.0713 


.0447 


8.17 


18.55 


26.72 


.0478 


.0218 


8,36 


18,97 


27,33 


.0717 


,0451 


8.18 


18.56 


26.74 


.0486 


.0226 


8.36 


18,98 


27,34 


.0721 


.0455 


8.18 


18.57 


26.75 


.0490 


.0229 


8,37 


18,99 


27,36 


.0729 


.0463 


8.19 


18.58 


26.77 


.0497 


.0237 


8,37 


19,00 


27,37 


. 0733 


.0467 


8.19 


18.59 


26.78 


.0501 


.0241 


8,38 


19,01 


27,39 


.0740 


.0474 


8.20 


18.60 


26 . 80 


.0509 


.0249 


8.38 


19,02 


27,40 


.0744 


.0478 


8.20 


18.61 


26.81 


,0513 


.0252 


8,39 


19,03 


27,42 


.0752 


.0486 


8.21 


18.62 


26.83 


.0521 


.0260 


8,39 


19,04 


27,43 


. 0756 


.0489 


8.21 


18.63 


26.84 


.0525 


.0264 


8,39 


19,05 


27.45 


.0764 


.0497 


8.21 


18.64 


26.85 


,0529 


.0268 


8,40 


19.06 


27.46 


.0768 


.0501 


8.22 


18.65 


26.87 


.0537 


.0275 


8,40 


19.07 


27.47 


.0772 


.0505 



Tables for vShortkning Calculations 

TABLE 31 (Continued). 



189 









Over- 








Over- 








condensation 








condensation 


Fat 


S. N. F. 


T. S. 


7.80- 

25.50 

Standard 


8.00- 

26.15 

Standard 


Fat 


S. N. F. 


T. S. 


7.80- 

25.50 

Standard 


8.00- 

26.15 

Standard 


8.41 


19.08 


27.49 


.0780 


.0512 


8.59 


19.50 


28.09 


.1015 


.0742 


8.41 


19.09 


27.50 


.0784 


.0516 


8.60 


19.51 


28.11 


. 1023 


.0750 


8.42 


19.10 


27.52 


.0792 


.0524 


S.60 


19.52 


28.12 


.1027 


.0753 


8.42 


19.11 


27.53 


.0796 


.0528 


S.61 


19.53 


28.14 


. 1035 


.0761 


8.43 


19.12 


27.55 


.0803 


.0535 


8.61 


19.54 


28.15 


. 1039 


.0765 


8.43 


19.13 


27.56 


.0807 


. 0539 


8.62 


19.55 


28.17 


.1047 


.0772 


8.43 


19.14 


27.57 


.0811 


.0543 


8.62 


19.56 


28.18 


.1050 


.0776 


8.44 


19.15 


27.59 


.0819 


.0551 


8.62 


19.57 


28.19 


.1054 


.0780 


8.44 


19.16 


27.60 


.0823 


.0554 


8.63 


19.58 


28.21 


.1062 


.0788 


8.45 


19.17 


27.62 


.0831 


.0562 


8.63 


19.59 


28.22 


.1066 


.0792 


8.45 


19.18 


27.63 


.0835 


.0566 


8.64 


19.60 


28.24 


.1074 


.0799 


8.46 


19.19 


27.65 


.0843 


.0574 


8.64 


19.61 


28.25 


.1078 


.0803 


8.46 


19.20 


27.66 


.0847 


.0577 


8.65 


19.62 


28.27 


.1086 


.0811 


8.47 


19.21 


27.68 


.0854 


.0585 


8.65 


19.63 


28.28 


.1090 


.0815 


8.47 


19.22 


27.69 


.0858 


.0589 


8.66 


19.64 


28.30 


.1098 


.0822 


8.47 


19.23 


27.70 


.0862 


.0593 


8.66 


19.65 


28.31 


.1101 


.0826 


8.48 


19.24 


27.72 


.0870 


.0600 


8.66 


19.66 


28.32 


.1105 


. 0830 


8.48 


19.25 


27.73 


.0874 


.0604 


8.67 


19.67 


28.34 


.1113 


.0837 


8.49 


19.26 


27.75 


.0882 


.0612 


8.67 


19.68 


28.35 


.1117 


.0841 


8.49 


19.27 


27.76 


.0886 


.0616 


8.68 


19.69 


28.37 


.1125 


.0849 


8.50 


19.28 


27.78 


.0894 


.0623 


8.68 


19.70 


28.38 


.1129 


.0853 


8.50 


19.29 


27.79 


.0898 


.0627 


8.69 


19.71 


28.40 


.1137 


.0860 


8.51 


19.30 


27.80 


.0901 


.0631 


8.69 


19.72 


28.41 


.1141 


.0864 


8.51 


19.31 


27.82 


.0909 


.0639 


8.70 


19.73 


28.43 


.1149 


.0872 


8.51 


19.32 


27.83 


.0913 


.0642 


8.70 


19.74 


28.44 


.1152 


.0876 


8.52 


19.33 


27.85 


.0921 


.0650 


8.70 


19.75 


28.45 


.1156 


.0880 


8.52 


19.34 


27.86 


.0925 


.0654 


8.71 


19.76 


28.47 


.1164 


.0887 


8.53 


19.35 


27.88 


.0933 


.0661 


8.71 


19.77 


28.48 


.1168 


.0891 


8.53 


19.36 


27.89 


.0937 


.0665 


8.72 


19.78 


28.50 


.1176 


.0899 


8.54 


19.37 


27.91 


.0945 


.0673 


8.72 


19.79 


28.51 


.1180 


. 0902 


8.54 


19.38 


27.92 


.0949 


.0677 


8.73 


19.80 


28.53 


.1188 


.0910 


8.55 


19.39 


27.94 


.0956 


.0685 


8.73 


19.81 


28.54 


.1192 


.0914 


8.55 


19.40 


27.95 


.0960 


.0688 


8.73 


19.82 


28.55 


.1195 


.0918 


8.55 


19.41 


27.96 


.0964 


.0392 


8.74 


19.83 


28.57 


.1203 


.0925 


8.56 


19.42 


27.98 


.0972 


.0700 


8.74 


19.84 


28.58 


.1207 


.0929 


8.56 


19.43 


27.99 


.0976 


.0704 


8.75 


19.85 


28.60 


.1215 


.0937 


8.57 


19.44 


28.01 


.0984 


.0711 


8.75 


19.86 


28.61 


.1219 


.0941 


8.57 


19.45 


28.02 


.0988 


.0715 


8.76 


19.87 


28.63 


.1227 


.0948 


8.58 


19.46 


28.04 


.0996 


.0723 


8.76 


19.88 


28.64 


.1231 


.0952 


8.58 


19.47 


28.05 


.1000 


.0727 


8.77 


19.89 


28.66 


. 1239 


.0960 


8.58 


19.48 


28.06 


.1003 


.0730 


8.77 


19.90 


28.67 


. 1243 


.0964 


8.59 


19.49 


28.08 


.1011 


.0738 


8.77 


19.91 


28.68 


.1247 


.0967 



190 



Standardizing Evaporatiid Milk 









TABLE 31 


[Continued). 








Fat 


S. N. F. 


T. S. 


Over- 
condensation 


Fat 


S. N. F. 


T. S. 


OVEB- 
C0NDEN.?ATrON 


7.80- 

25.50 

Standard 


8.00- 

26.15 

Standard 


7.80- 
25,50 
Standard S( 


8 00- 
26.15 
andard 


8.78 


19.92 


28.70 


. 1254 


.0975 


8.89 


20.18 


29.07 


.1400 


1117 


8.78 


19.93 


28.71 


.1258 


.0979 


8.90 


20.19 


29.09 


.1407 


1124 


8.79 


19.94 


28.73 


.1266 


.0987 


8.90 


20.20 


29.10 


.1411 


1128 


8.79 


19.95 


28.74 


.1270 


.0990 


8.91 


20.21 


29.12 


.1419 


1136 


8.80 


19.96 


28.76 


.1278 


.0998 


8.91 


20.22 


29.13 


.1423 


1140 


8.80 


19.97 


28.77 


.1282 


.1002 


8.92 


20.23 


29.15 


.1431 


1147 


8.81 


19.98 


28.79 


.1290 


.1010 


8.92 


20.24 


29.16 


. 1435 


1151 


8.81 


19.99 


28.80 


.1294 


. 1013 


8.92 


20.25 


29.17 


.1443 


1155 


8.81 


20.00 


28.81 


.1298 


.1017 


8.93 


20.26 


29.19 


.1447 


1163 


8.82 


20.01 


28.83 


. 1305 


.1025 


8.93 


20.27 


29.20 


.1450 


1166 


8.82 


20.02 


28.84 


. 1309 


.1029 


8.94 


20.28 


29.22 


.1458 


1174 


8.83 


20.03 


28.86 


.1317 


. 1036 


8.94 


20.29 


29.23 


•. 1462 


1178 


8.83 


20.04 


28.87 


. 1321 


.1040 


8.95 


20.30 


29.25 


.1470 


1185 


8.84 


20.05 


28.89 


.1329 


.1048 


8.95 


20.31 


29.26 


.1474 


1189 


8.84 


20.06 


28.90 


. 1333 


.1052 


8.96 


20.32 


29.28 


.1483 


1197 


8.84 


20.07 


28.91 


.1337 


.1058 


S.96 


20.33 


29.29 


.1486 


1201 


8.85 


20.08 


28.93 


. 1345 


.1063 


8.96 


20.34 


29.30 


.1490 


1205 


8.85 


20.09 


28.94 


.1349 


.1067 


8.97 


20.35 


29.32 


.1498 


1212 


8.86 


20.10 


28.96 


.1356 


.1075 


8.97, 


20.36 


29.33 


. 1501 


1216 


8.86 


20.11 


28.97 


.1360 


.1078 


8.98 


20.37 


29.35 


.1509 


1224 


8.87 


20.12 


28.99 


.1368 


.1086 


8.98 


20.38 


29.36 


.1513 


1228 


8.87 


20.13 


29.00 


.1372 


.1090 


S.99 


20.39 


29.38 


.1521 


1235 


8.88 


20.14 


29.02 


.1380 


.1098 


8.99 


20.40 


29.39 


.1525 


12.39 


8.88 


20.15 


29.03 


.1384 


.1101 


8.99 


20.41 


29.40 


.1529 


1243 


8.88 


20.16 


29.04 


.1388 


.1105 


9.00 


20.42 


29.42 


.1537 


1250 


8.89 


20.17 


29.06 


.1396 


.1113 













Table 31 gives the percentage of fat, S. N. F. and T. S. all in 
the proper ratio one to the other for standardizing evaporated 
milk upon the double basis of 7.80 per cent of fat, and 25.50 per 
cent of T. S., and 8.00 per cent of fat and 26.15 per cent of T. S. 
The table has a range from 7.00 per cent to 9.00 per cent of fat, 
and from 15.88 per cent to 20.52 per cent of S. N. F. The table 
also gives the factor of overcondensation from 7.80 to 9.00 and 
from 8.00 to 9.00. 

This table is intended to be used when standardizing after 
condensing, and also when standardizing with the use of con- 
densed milk products. One example will suffice to show its use. 
Example : Evaporated milk after condensing contains 8.25 per 



IvEY TO Formulas 191 

Cent of fat and 19.21 per cent S. N. F. Reference to the table 
shows that for 8.25 per cent of fat the S. N. F. should be 18.71 
per cent. The difference between 19.21 and 18.71 is .50 or the per 
cent of S. N. F. that is to be standardized. The table gives results 
that could not be obtained otherwise than by a long calculation, 
and it also helps to prevent errors. The method for applying the 
factor of overcondensation will be discussed in another paragraph 
of this chapter, 

KEY TO FORMULAS FOR STANDARDIZING EVAPORATED MILK. 

The following key gives the information required for substi- 
tuting values or figures for letters in the formulas found in this 
chapter : 

A = The desired per cent of fat in the standardized product. 

B = The desired per cent of S. N, F. in the standardized product. 

B^ = The per cent of S. N. F. in evaporated milk, before standard- 
izing. 

C = The desired per cent of T. S. in the standardized product. 

D ~ The per cent of T. S. in condensed whole milk. 

D^ = The pounds of evaporated milk, before standardizing. 

D-= The pounds of unsweetened condensed whole milk. 

F = The per cent of fat in the whole milk. 

F^ ^ The per cent of fat in butter. 

G = The per cent of fat in the cream. 

J = The per cent of S. N. F. in the cream. 

J' — The per cent of T. S. in the cream. 

J- — - The per cent of S. N. F. in the evaporated milk before stand- 
ardizing. 

K^ := The per cent of fat in the skim-milk. 

K- = The per cent of fat in the evaporated milk, before standard- 
izing. 

K = The per cent of fat in the unsweetened condensed whole 
milk. 

L =: The pounds of skim-milk required. 

L^ = The pounds of unsweetened condensed skim-milk. 

M = The per cent of S. N. F. in the condensed whole milk. 

N =r The per cent of S. N. F. in the skim-milk. 

= The pounds of cream required. 

0^ = The per cent of T. S. in the mixed batch. 



192 Standardizing Evaporatrd AIilk 

P =z The pounds of whole milk in the batch. 

pi rzi The pounds of butter. 

Q = The per cent of S. N. F. in the condensed skim-railk, 

R =: The desired ratio of S. N. F. to fat. 

Ri = The desired ratio of T. S. to fat. 

S = The per cent of S. N. F. in the whole milk. 

S^ =r The average per cent of fat in the mixed batch. 

S- = The average per cent of S. N. F, in the mixed batch. 

T = The per cent of T. S. in whole milk. 

T^ = The per cent of T. S. in evaporated milk. 

T-= The per cent of T. S. in "condensed skim-milk. 

W;= The pounds of water to be added. 

PROVIDING FACTOR OF SAFETY. 

In all the problems given, the calculations are made upon the 
basis of the absolute standard without allowing any factor of 
safety. It is recommended that in practice, in the case of evapo- 
rated milk, a factor of safety of about .05 per cent of fat, and 
about .20 per cent of T. S. be allowed. When plenty of time is 
available for retests this factor of safety may be very slightly 
reduced. 

PROBLEM 7. STANDARDIZING EVAPORATED MILK BEFORE 

CONDENSING. HOW TO CALCULATE POUNDS OF 

SKIM-MILK TO ADD TO WHOLE MILK. 

The ratio between the percentage of S. N. F. and the percen- 
tage of fat in the whole milk must be more than the required 
ratio. 

Solution of Problem 7, Based Upon Rule 4: 

(1.) Divide the percentage of fat in the skim-milk b}' the ra- 
tio between the S. N. F. and the fat in the product desired. Sub- 
tract answer from the S. N. F. in the skim-milk. Call remainder 
A., or the percentage of 8. N. F. in the skim-milk available for 
standardizing. 

(2.) Divide the percentage of fat in the whole milk by the 
ratio between the S. N. F. and the fat in the product desired. Call 
the result B. Subtract from B the percentage of S. N. F. present 
in the whole milk. Multiply the remainder by the pounds of 



Probi,i;ms Before Condensing 



193 



whole milk present in the batch. Call the result C, or the pounds 
S. N.F. short. 

(3.) Divide C by A. The answer will be the pounds of skim- 
milk necessary to standardize the batch to the required ratio. 

Solution of Problem 7, Based Upon Formula 6 : 



N — 



R 



Problem 7, Example 9 : 





Pounds 


Per Cent 


Products 


Fat 


S. N. F. 


T. S. 


Milk 


10,000 


3.79 

.16 

7.80 


8.31 

8.47 

17,70 


12.10 


Skim-milk 


8.63 


Composition desired 




25.50 









Ratio 1 S. N. F. to .4407 fat desired. 
Ratio 1 S. N. F. to .4561 fat in whole milk. 

Solution of Problem 7, Example 9, Based Upon Rule 4 : 

(1.) To calculate the available S. N. F, in the skim-milk. 

.16 -f- .4407 = .36, per cent of S. N. F. required to equalize the 

fat in the skim-milk. 
8.47 — .36=8.11, per cent of S. N. F. available for standardizing. 

(2.) To calculate the pounds of S. N. F. short. 
3.79 ~ .4407 = 8.60, per cent of S. N. F. required. 
8.60 — 8.31 = .29, per cent of S. N. F. short. 
10000 X .0029 = 29, pounds of S. N. F. short. 

(3.) To calculate the pounds of skim-milk required. 
29-:-.0811=358, pounds of skim-milk required. 



194 Standardizing Evaporated Milk 

Solution of Problem 7, Based Upon Formula 6: 

.0379 

— .usyi I X iu,uuu 

358 



V .4407 / 



.0847 



.0016 



.4407 



Proof of Problem 7, Example 9 : 





Pound 


Pounds 


Per Cent 


Products 


Fat 


S. N. F. 


T. S. 


Fat 


S. N. F. 


T. S. 


Milk 


10,000 

t,358 

10,358 


379 
1 

80 


831 
30 

861 


1210 
31 

124 


3.79 
.16 

3.66 


8.31 

8.47 

8.31 


12.10 


Skim-milk 


8.63 


Standardized 

product 


11.01 







Ratio 1 S. N. F. to .4407 fat obtained in product after stand- 
ardizing. 

STANDARDIZING EVAPORATED MILK BEFORE CONDENSING. 

Problem 8 : How to Calculate Pounds of Cream to Add to Whole 

Milk: 

Ratio between the percentage of S. N. F. and fat in the whole 
milk must be less than the required ratio. 

Solution of Problem 8, Based Upon Rule 5 : 

(1.) Multiply the percentage of S. N. F. in the cream by the 
ratio between the S. N. F. and the fat in the product desired. 
Subtract the result from the percentage of fat in the cream. Call 
the reminder A, or the percentage of fat in the cream available for 
standardizing. 

(2.) Multiply the percentage of S. N. F. in the whole milk by 
the ratio between the S. N. F. and the fat in the product desired. 
Call the result B, or the percentage of fat required. Subtract from 
B the percentage of fat in the whole milk. Multiply the remain- 
der by the pounds of whole milk in the batch. Call the result C, 
or the pounds of fat short. 



Probli;ms Before Condensing 



195 



3. Divide C by A. The answer will be the pounds of cream 
required to standardize the batch to the desired ratio. 

Solution of Problem 8, Based Upon Formula 7: 

[(SR)— F] P 



= 
Problem 8, Example 10 : 



G— (JR) 



Products 


Pounds 


Per Cent 


Fat 


S. N. F. 


T. S. 


Milk 

Cream 


10,000 


3.35 
26.38 

7.80 


8.63 
6.44 

17.70 


11.98 
32.82 


Composition desired after 
condensing 




25.50 









Ratio of 1 S. N. F. to .4407 fat desired. 
Ratio of 1 S. N. F. to .3793 fat in whole milk. 

Solution of Problem 8, Example 10, Based Upon Rule 5 : 

(1.) To calculate the available fat in the cream. 
6.44 X .4407 = 2.84, per cent of fat required to equalize the 

S. N. F. in the cream. 
26.38 — 2.84 = 23.54, per cent of fat available for standardizing. 

(2.) To calculate the pounds of fat short. 

8.63 X .4407 = 3.80, per cent of fat required. 
3.80 — 3.35 = .45, per cent of fat short. 
lOOOOX. 0045=45, pounds of fat short. 

(3.) To calculate the pounds of cream required. 
45-^,2354=192, pounds of cream required. 



196 Standardizing Evaporated Milk 

Solution of Problem 8, Example 10, based upon Formula 7 : 

(. 0863 X. 4407)— .0335] X 10,000 



= 

.2638— (.0644 X -4407) 

Proof of Problem 8, Example 10 : 



:192 





Pounds 


Pounds 


Per Cent 


Products 


Fat 


S. N. F. 


T. S. 


Fat 


S. N. F. 


T. S. 


Milk 


10,000 
192 

10,192 


335 
51 

386 


863 
12 

875 


1198 
63 

1261 


3.35 
26.38 

3.79 


8.63 
6.44 

8.59 


11.98 


Cream 


32.82 


Standardized 

product 


12.38 



Ratio 1 S. N. F. to .4407 fat obtained in product after stand- 
ardizing. 

STANDARDIZING EVAPORATED MILK BEFORE CONDENSING. 
Problem 9; How to Calculate the Pounds of Cream to Add to 

Skim-milk. 

Solution of Problem 9, Based Upon Rule 6 : 

(1.) Multiply the percentage of S. N. F. in the cream by the 
ratio between the S. N. F. and the fat in the product desired. 
Subtract the result from the percentage of fat in the cream. 
Call the remainder A, or the percentage of fat in the cream avail- 
able for standardizing. 

(2.) Multiply the percentage of S. N. F. in the skim-milk by 
the ratio between the S. N. F. and the fat in the product desired. 
Call the result B. Subtract from B the percentage of fat in the 
skim-milk. Multiply the remainder by the pounds of skim-milk 
in the batch. Call the result C. 

(3.) Divide C by A. The answer will be the number of pounds 
of cream necessary to standardize the batch to the required ratio. 

Solution of Problem 9, Based Upon Formula 8 : 

(NR)— K] L 



O 



G— (JR) 



Problems Before Condensing 197 

Problem 9, Example 11. 





Pounds 


Per Cent 


Products 


Fat 


S. N. F. 


T. S. 


Skim-milk 


10,000 


.20 
26.38 

7.80 


8.63 
6.44 

17.70 


8.83 


Cream 


32.82 


Composition desired after 
condensing 




25.50 









Desired ratio between S. N. F. and fat is 1 to .4407. 

Solution of Problem 9, Example 11, Based Upon Rule 6: 

(1.) To calculate the available fat in the cream. 
6.44 X .4407 = 2.84, per cent of fat required to equalize the 

S. N. F. in the cream. 
26.38 — 2.84 = 23.54, per cent of fat in the cream available for 

standardizing. 

(2.) To calculate the pounds of fat short. 
8.63 X .4407 = 3.80, per cent of fat required. 
3.80 — .20 = 3.60, per cent of fat short. 
10000X.036 = 360, pounds of fat short. 

(3.) To calculate the pounds of cream required. 

360-=-.2354=1530, pounds of cream required. 

Solution of Problem 9, Example 11, Based Upon Formula 8: 

[(.0863 X .4407) — .0020] X 10,000 
^ = .2638-(.0644X.4407) = ^^^^'^^ 

Proof of Problem 9, Example 11 : 



Products 


Pounds 


Pounds 


Per Cent 




Fat 


S. N. F. 


T. S. 


Fat 


S. N. F. 


T. S. 


Skim-milk 

Cream 


10,000 
1,530.33 

11,530.33 


20.00 
403.74 

423.74 


863 
98.48 

961.48 


883 
502.22 

1385.22 


.20 
26.38 

3.675 


8.63 
6.44 

8.33 


8.83 
32.82 


Standardized 
product 


12.00 



198 



Standardizing Evaporated Milk 



Ratio of 1 S. N. F. to .4407 fat obtained in product after stand- 
ardizing. 

STANDARDIZING EVAPORATED MILK BEFORE CONDENSING. 
Problem 10. How to Calculate the Weight of Cream to Add, 
Knowing the Weight of the Whole Milk and the Skim-milk onj 
Hand, and the Percentages of Fat and Solids Not Fat of All 
Three Products. 

Solution of Problem 10, Based Upon Rule 7 : 

(1.) If the ratio between the percentage of fat and the S. N. F. 
in the fresh milk is less than the required ratio, standardize the 
fresh milk with the skim-milk, using Rule 4. Deduct the weight 
of the skim-milk required to standardize the fresh milk from the 
total weight of skim-milk on hand. 

(2.) If the ratio between the percentage of fat and S. N. F. 
in the fresh milk is less than the required ratio, standardize the 
fresh milk with cream, using Rule 5. 

(3.) Now standardize the skim-milk remaining under 1, or all 
the skim-milk on hand, as in the case under number 2, using Rule 
5 to arrive at amount of cream necessary to add in either case. 
Make the necessary calculations to get proper weights under the 
double standardization. 

Solution of Problem 10, Based Upon the Use of Formulas as Indi- 
cated : 

(1.) To calculate the pounds of cream to add to the whole 
milk. 

Use Formula 7, page 195. 

(2.) To calculate the pounds of cream to add to the skim-milk. 

Use Formula 8, page 196. 

Problem 10, Example 12: 



Products 


Pounds 


Per Cent 




Fat 


S. N. F. 


T. S. 


Whole Milk 


10,000 

75 


3.58 
.16 

28.38 


8.40 

8.47 
6.44 


11 98 


Skim-milk 


8 63 


Cream 


34 82 









Pesired ratio of S. N. F, to fat is 1 to .4407, 



Probi^Ems Bf;pore Condensing 199 

Solution of Problem 10, Example 12, Based Upon Rule 7 : 

A. (1.) To calculate the available fat in the cream. 

6.44 X .4407 = 2.84, per cent of fat required to equalize the 

S. N. F. in the cream. 
26.38 — 2.84 == 23.54, per cent of fat available for standardiz- 
ing. 

(2.) To calculate the pounds of fat short. 
8.40 X .4407 = 3.70, per cent of fat required. 
3.70 — 3.58 = .12, per cent fat short. 
10000 X .0012 = 12, pounds of fat short. 

(3.) To calculate the pounds of cream required. 

12-^.2354=51.75, the pounds of cream required to standardize 

the whole milk. 
Should the whole milk require skim-milk instead of cream, use 
Rule 4, and subtract the pounds of skim-milk required from the 
total pounds of skim-milk and then standardize the balance of the 
skim-milk, using Rule 5. 

B. Calculating available fat in the cream. 

(1.) To calculate the available fat in the cream. 
Same as under A (1) above. It equals 23.54%. 

(2.) To calculate pounds fat short. 

8.47 X .4407 = 3.73, per cent of fat required. 
3.73 — .16 = 3.57, per cent of fat short. 
75 X .0357 = 2.68, pounds of fat short. 

(3.) To calculate the pounds of cream required. 

2.68-f-. 2354=11.4, the pounds of cream required to standardize 

the skim-milk. 

C. Adding together answers obtained under A and B=51.75 
plus 11.43 = 63.18 pounds cream required to standardize the entire 
batch. 

Solution of Problem 10, Example 12, based upon Formulas 7 and 8. 

(1.) To calculate the pounds of cream to add to the whole 
milk. 



200 



= 



Standardizing Evaporated Milk 

(.0840 X .4407) — .0358] X 10,000 
.2638— (.0644 X .4407) 



51.75 



(2.) To calculate the pounds of cream to add to the skim- 
milk. 

[(.0847X.4407)— .0016175 

O — - - - — 114'^ 

.2638— (.0644 X. 4407) ~ 

51.75 -f 11.43 = 63.18, or total pounds of cream required. 
Proof of Problem 10, Example 12 : 



Products 


Pounds 


Pounds 


Per Cent 




Fat 


S. N. F. 


T. S. 


Fat 


S. N. F. 


T. S. 


Whole milk 

Skim-milk 

Cream 

Standardized 
product 


10,000 
75 
63.18 

10,138.18 


358 
.12 
16.64 

374.76 


840 
6.35 
4.20 

850.55 


1198 
6.47 
20.84 

1225.31 


3.58 

.16 

26.38 

3.69 


8.40 
8.47 
6.44 

8.38 


11.98 

8.63 

32.82 

12.07 



Ratio of S. N. F. to fat obtained is 1 to .4407. 

STANDARDIZING EVAPORATED MILK BEFORE CONDENSING. 
Problem 11 : How to Calculate the Pounds of Butter to Add. 



Butter can frequently be used to good advantage in standardiz- 
ing evaporated milk. Several methods of calculation are possible, 
but only the one that gives the desired result in the smallest num- 
ber of calculations is given herewith. 

Solution of Problem 11, based upon Rule 8 : 

(1.) Multiply the percentage of S. N. F. in the fresh milk by 
the ratio between the S. N. F. and the fat in the product desired. 
Subtract from this the percentage of fat in the fresh milk. Mul- 
tiply the remainder by the pounds of the fresh milk in the batch. 
Divide the product by the percentage of fat in the butter, which 
will give the answer, or the pounds of butter to be added to the 
entire batch. 



Problems After Condensing 201 

Solution of Problem 11, Example 13 : 



Products 


Pounds 


Per Cent 




Fat 


S. N. F. 


T. S. 


Milk 


10,000 


3.58 
80.00 

7.80 


8.40 


11.98 


Butter 




Composition desired after 
condensing 




17.70 


25.50 









Desired ratio of S. N. F. to fat is 1 to .4407. 

Solution of Problem 11, Example 13, based upon Rule 8: 

(1.) To calculate the pounds of butter required. 
8.40 X .4407 = 3.70, per cent of fat required to equalize the 

S. N. F. in the whole milk. 
3.70— 3.58=.12, per cent of fat short. 
10000X.0012=12.0, pounds of fat short. 
12.0-:- 80=15, pounds of butter required. 

Solution of Problem 11, Example 13, based upon Formula 8: 

(.0840X. 4407)— .0358] 10000 



P^r= 



.80 



=il5 



Proof of Problem 11, Example 13: 



Products 


Pounds 




Pounds 




Per Cent 




Fat 


S. N. F. 


T. S. 


Fat 


S. N. F. 


T. S. 


MUk 

Butter 


10,000 
15.23 

10,015.23 


358 
12.18 

370.18 


840 
840 


1198 
12.18 

1210.18 


3.58 
80.00 

3.69 


8.40 


11.98 


Standardized 
product 


8.38 


12.08 



Ratio 1 S. N. F. to .4407 fat obtained in product after stand- 
ardizing. 



202 



Standardizing Evaporate;d Milk 



STANDARDIZING EVAPORATED MILK REFORE CONDENSING. 

Problem 12: How to Calculate the Pounds of Cream or Skim- 
milk to Use, when Mixing Together Fresh Milk and 
Bulk Condensed Whole Milk. 

Solution of Problem 12, based upon Rule 9: 

(1.) Calculate the average fat and S. N. F. test of the mixed 
fresh milk and bulk condensed milk. Get ratio of fat to S. N. F. 
in the mixed milk. 

(2.) If skim-milk is required, calculate the amount necessary 
to add to the mixture by means of Rule 4. 

(3.) If cream is required, calculate the amount necessary to 
add to the mixture by means of Rule 5. 

Solution of Problem 12, based upon Formula 9 : 

(1.) To calculate the percentage of fat in the batch after 
mixing together the whole milk and the bulk condensed whole 
milk. 

^, ^ (PF) + (D^K^) 
P + D2 
(2.) To calculate the percentage of T. S. in the batch, after 
mixing together the whole milk and the bulk condensed whole 
milk. 

Q,^ (PT) + (D^D) 
P + D 
(3.) If skim-milk is required calculate according to Formula 
6, page 193. 

(4.) If cream is required, calculate according to Formula 7, 
page 195. 

Problem 12, Example 14: 



Products 


Pounds 


Per Cent 




Fat 


S. N. F. 


T. S. 


Milk 


10,000 

872 


3.58 
10.73 
26.38 

7.80 


8.41 

25.27 

6.44 

17.70 


11.99 


Bulk condensed milk 

Cream 


36.00 

32.82 


Composition desired after 
condensing 




25.50 









Desired ratio of solids not fat to fat is 1 to .4407. 



ProbIvE;ms After Condensing 
Solution of Problem 12, Example 14, based upon Rule 9 : 



203 



(1.) To calculate the average fat and T. S. tests of the mixed 
fresh milk and bulk condensed milk. 



Products 


Total 
Pounds 


Fat 


T. 


S. 




Per Cent 


Pounds 


Per Cent 


Pounds 


Whole milk 

Bulk condensed 

whole milk 

Mixed milk 


10,000 

872 
10,872 


3.58 

10.73 
4.15 


358.00 

93.60 
451.60 


11.99 

36.00 
13.91 


1199.00 

313.92 
1512.92 



(2.) To calculate the pounds of cream required follow solu- 
tion of Problem 8, Example 10, based upon Rule 5, page 194. The 
answer will be 68.18 or the pounds of cream necessary to add. 
Should the mixed milk require skim-milk instead of cream, follow 
the solution of Problem 7, Example 9, based upon Rule 4, page 192. 

Solution of Problem 12, Example 14, based upon Formula 9 : 

(1.) To calculate the percentage of fat in the batch after 
mixing together the whole milk and the bulk condensed whole 
milk. 



S^ = 



(10000X.0358) + (872X.1073) 



4.15 



10000+872 

(2.) To calculate the percentage of T. S. in the batch after 

mixing together the whole milk and the bulk condensed whole 
milk. 

0^ = (IQQQO X -1199) + (872 X .36) ^ ^^ ^^ 
10000 + 872 



(3.) To calculate the pounds of cream required, follow the 
solution of Problem 8, Example 10, based upon Formula 7, page 
195. The answer will be 68.18, or the pounds of cream necessary 
to add. Should the mixture require skim-milk instead of cream, 
follow the solution of Problem 7, Example 9, based upon Formula 
6, page 193. 



204 Standardizing Evaporated Milk 

Proof of Problem 12, Example 14: 



Products 


Pounds 


Pounds 


Per Cent 




Fat 


S. N. F. 


T. S. 


Fat 


S. N. F. 


T. S. 


Milk 


10,000 

872 
68.18 

10,940.18 


358.00 
93.6 
17.98 

469.58 


841 . 00 

220 . 22 

4.20 

1065.42 


1199.00 
313.82 

22.18 

1535.00 


3.58 
10.73 

26.38 

4.29 


8.41 

25.27 
6.44 

9.73 


11.99 


Bulk cond. milk . . 
Cream 


36.00 
32.82 


Standardized 
product 


14.02 



Ratio of 1 S. N. F. to .4407 fat obtained in product after stand- 
ardizing. 

STANDARDIZING EVAPORATED MILK BEFORE CONDENSING. 
Problem 13: How to Calculate When Adding Water Only. 

Ascertain from the test of the condensed product the ratio 
between the percentage of S. N. F. and the percentage of fat. If 
the ratio is the same as in the standard, standardize with water 
only. In case the ratio between the S. N. F. and the fat is differ- 
ent than the desired ratio, and if it should be possible or prac- 
ticable to standardize with water only, standardize down to the 
lowest constituent that may happen to govern — that is, the fat or 
the S. N. F. If this is not done, the resulting product will be low 
in either fat or S. N. F. Two solutions of this problem are given. 

Solution of Problem 13, based upon Rule 10 : 

(1.) Subtract the percentage of T. S. desired from the per- 
centage of T. S. in the milk that is to be standardized. Divide the 
remainder by the percentage of T. S. desired. Multiply the answer 
by the pounds of milk in the batch. The answer will be the 
pounds of water required. 

The above coefficient of overcondensation can be ascertained 
directly by referring to Table 31, which gives this value upon 
the double basis of 7.80 per cent of fat and 25.50 per cent of T. S. 
and 8.00 per cent of fat and 26.15 per cent of T. S. When Table 31 
is available, this makes the simplest method of calculating the 
amount of water required. 



Problems Before Condensing 
Solution of Problem 13, based upon Formula 10: 



205 



W 



Problem 13, Example 15: 



C 



D^ 



Products 


Pounds 


Per Cent 




Fat 


S. N. F. 


T. S. 


Evaporated milk 

Composition desired 


4644 


8.106 
7.80 


18.40 
17.70 


26.506 
25.500 



Solution of Problem 13, Example 15, based upon Rule 10 : 

26.50 — 25.50= 1.00, per cent of T. S. in excess. 
1.00 -:- 25.50 =: ,0392, coefficient of overcondensation. 
4644 X .0392 = 182, pounds of water required. 

Solution of Problem 12, Example 15, based upon Formula 10 : 



W = 



/26.50 - 25.50 X^^^^ 
\ 25.50 / 



182 



Solution of Problem 13, based upon Rule 11 : 

(1.) Subtract the percentage of fat desired from the percent- 
age of fat in the batch that is to be standardized. Multiply the 
pounds of milk in the batch by the remainder. Divide the prod- 
uct by the percentage of fat desired. The answer will be the 
pounds of water required to standardize the batch. 

By this method the T. S. can be used as a basis for making the 
calculations as well as the fat. This is the simpler of the two 
methods, unless in the case of the preceding method the factor 
of overcondensation can be obtained directly from a table which 
can be especially prepared to cover any standard that might be 
desired, and covering a wide range of tests. 

Solution of Problem 13, based upon Formula 11: 

A 
Solution of Problem 13, Example 15, based upon Rule 11 : 

8.106 — 7.80 ^= .306, per cent of fat in excess. 



206 



Standardizing Evaporated Milk 



4644X .00306=14.21, pounds of fat in excess. 
14.21h-.0780=:182, pounds of water required. 

Solution of Problem 13, Example 15, based upon Formula II : 

(.08106— .078) 4644 



W 



.078 



r=182 



Proof of Problem 13, Example 15, covering both Rules 10 and 11 : 



Products 


Pounds 


Pounds 


Per Cent 




Fat 


S. N. F. 


T. S. 


Fat 


S. N. F. 


T. S. 


Evaporated milk.. 
Water 


4644 
182 

4826 


376.4 


854.4 


1230.8 


8.106 


18.40 


26.50 


Standardized 
product 


376.4 


854.4 


1230.8 


7.80 


17.70 


25.50 



No factor of safety was allowed in the above problem. It is 
recommended that a margin be allowed of .05 per cent upon fat 
and .20 per cent upon T. S., where the product is standardized 
upon the basis of both the fat and the S. N. F. The same margin 
is recommended where the standardization is based upon one con- 
stituent only. 

STANDARDIZING EVAPORATED MILK BEFORE CONDENSING. 

Problem 14 : How to Calculate When Both Condensed Skim-milk 
and Water are Required for Standardizing. 

Solution of Problem 14, based upon Rule 12 : 

(1.) Subtract the percentage of fat desired from the percent- 
age of fat in the batch before standardizing. Multiply the re- 
mainder by the pounds of milk in the batch. Divide the product 
by the percentage of fat desired. Call answer A, or the total 
pounds that the batch is short. 

(2.) Divide the percentage of fat in the batch to be standard- 
ized by the ratio between the T. S. and the fat, in the product de- 
sired. Subtract from the answer the percentage of T. S. in the 
batch to be standardized. Multiply the remainder by the pounds 
in the batch before standardizing. Divide the product by the per- 
centage of T. S. in the skim-milk to be used for standardizing. 



Problems Before Condensing 



207 



Call the answer B, or the pounds of skim-milk required. Sub- 
tract B from A. Call the remainder C, or the pounds of water re- 
quired. 

(3.) Add A and C to the pounds in the batch before stand- 
ardizing. The sum will be the total pounds in the batch after 
standardizing with both water and skim-milk. 

Solution of Problem 14, based upon Formula 12: 

(1.) To calculate the pounds of condensed skim-milk re- 
quired. 



U = 



(i-^0 



D^ 



T- 



(2.) 



To calculate the pounds of water required. 

■(K^— A) D^ 



W = 



r(K -A) PI 



— L^ 



Problem 14, Example 16: 



Products 


Pounds 


Per Cent 




Fat 


S. N. F. 


T.S. 


Evaporated milk 

Condensed skim-milk .... 


10000 


8.00 


18.00 


26.00 
25.50 


Water 










Composition desired 




7.80 


17.70 


25.50 







Solution of Problem 14, Example 16, based upon Rule 12 : 

(1.) To calculate the pounds that the batch is short. 
8.00 — 7.80 r= .20, per cent of fat in excess. 
10000 X .0020 = 20, pounds of fat in excess. 

20-^.0780= 256, total pounds that the batch is short. 
(2.) To calculate the pounds of condensed skim-milk and 
pounds water necessary to add. 
8.00 -f- .3059 = 26.15, per cent of total solids necessary to 

equalize the fat in the batch. 
26.15 — 26.00 = .15, per cent of total solids required to be 

added to equalize the fat in the batch. 
10000 X .0015 =: 15, pounds of total solids required. 



208 



Standardizing Evaporated Milk 



15 ^-.255 = 59, pounds of condensed skim-milk required. 
256 — 59 = 197, pounds of water required. 
(3.) Material in batch after standardizing. 
59 pounds of condensed skim-milk. 
197 pounds of water. 
10,000 pounds before standardizing. 



10,256 pounds total after standardizing. 

Solution of Problem 14, Example 16, based upon Formula 12 : 

(1.) To calculate the pounds of condensed skim-milk re- 
quired. 



U = 



( •^^^^ — .2600^ X 10000 
.3059 / 



.2550 



= 59.6 



[2.) To calculate the pounds of water required. 
(8.00 — 7.80) X 10000 



w = 



I 



7.80 



1 



59 = 196.8 



Proof of Problem 14, Example 16: 



Products 


Pounds 


Pounds 


Per Cent 




Fat 


S .N. F. 


T. S. 


Fat 


S. N. F. 


T. S. 


Evaporated milk.. 
Condensed skim- 
milk 


10,000.0 

59.6 
197.0 

10,256.6 


800 


1800 
15 


2600 
15 


8.00 


18.00 
25.50 


26.00 
25.50 


Water 




Standardized 
product 


800 


1815 


2615 


7.80 


17.70 


25.50 



No factor of safety allowed in the above problem. 

STANDARDIZING EVAPORATED MILK AFTER CONDENSING. 

Problem 15 : How to Calculate When Both Cream and Water are 
Required for Standardizing. 

Solution of Problem 15, based upon Rule 13 : 

(1.) Subtract the percentage of S. N. F. desired from the 
percentage of S. N. F. in the batch before standardizing. Multi- 



Problems After Condensing 



209 



ply the remainder by the pounds of milk in the batch. Divide 
the product by the percentage of S. N. F. desired. Call the answer 
A, or the pounds that the batch is short. 

(2.) Multiply the percentage of S, N. F. in the batch by the 
ratio between the S. N. F. and the fat in the product desired. Sub- 
tract from the answer the percentage of fat in the batch to be 
standardized. Multiply the remainder by the pounds in the batch 
before standardizing. Divide the product by the percentage of 
fat in the cream to be used for standardizing. Call the answer B, 
or the pounds of cream required. Subtract B from A. Call the 
answer C, or the pounds of water required. 

(3.) Add A and C to the pounds in the batch before standard- 
izing. The sum of the three values will be the total pounds in 
the batch after standardizing with both water and cream. 

Solution of Problem 15, based upon Formula 13 : 

(1.) To calculate the pounds of cream required: 



= 



[ (B^XR)— K^] XD ^ 
G 



(2.) To calculate the pounds of water required. 

(Bi — B) XD^ 



Problem 15, Example 16: 



B 



O 



Products 


Pounds 


Per Cent 




Fat 


S. N. F. 


T. S. 


Evaporated milk 

Cream 


10,000 


7.00 
40.00 


20.00 


27.00 


Water 








Composition desired 




7.80 


17.70 


25.50 









Solution to Problem 15, Example 16, based upon Rule 13; 

(1.) To calculate the pounds that the batch is short. 
20.00 — 17.7 = 2.30, per cent of S. N. F. in excess. 
10000 X .023 = 230, pounds of S. N. F. in excess. 
230 -f- .177 = 1299, pounds that the batch is short. 



I 



210 



Standardizing Evaporated Milk 



(2.) To calculate the pounds of cream and water necessary. 

20.00 X .4407 = 8.81, per cent of fat necessary to equalize the 
S. N. F. in the unstandardized batch. 
8.81 — 7.00 ^ 1.81, per cent of fat required to equalize the 
S. N. F. in the batch. 
10000 X. 0181=181, pounds of fat required. 

181 -^- .40 = 453, pounds of 407p cream required. 
1299 — 453 = 846, pounds of water required. 

(3.) Material in batch after standardizing. 
458 pounds of 40% cream. 
846 pounds of water. 
10000 pounds before standardizing. 



J1299 pounds total in batch after standardizing. 

Solution of Problem 15, Example 16, based upon Formula 13: 
(1.) To calculate the pounds of cream required. 

[ (.20 X .4407) — .07] X 10000 



0=: 



.40 



453 



(2.) To calculate the pounds of water required. 

(.20— .1770) X 10000 



w = 



.1770 



— 453 = 846 



Proof of Problem 15, Example 16: 



Products 


Pounds 


Pounds 


Per Cent 




Fat 


S. N. F. 


T. S. 


Fat 


S. N. F. 


T. S. 


Evaporated milk. . 
Cream .... 


10,000 
453 

846 

11,299 


700 
181.4 


2000 


2700 
181 


7.00 
40.00 


20.00 


27.00 


Water 






Standardized 
product 


881.4 


2000 


2881 


7.80 


17.70 


25.50 



No factor of safety allowed in the above calculation. Also the 
S. N. F. in the cream was disregarded in the calculation. In the 
above example this would increase the total solids to the extent of 
about 27 pounds, making the actual total solids 25.65 per cent in- 
stead of 25.50 per cent as indicated in the proof. 



pROBLKMs After Condensing 211 

STANDARDIZING EVAPORATED MILK AFTER CONDENSING. 

Problem 16: How to Calculate When Condensed Whole Milk, 

Condensed Skim-milk and Water Are Required 

for Standardizing. 

Solution of Problem 16, based upon Rule 14 : 

(1.) Call the T. S. in the condensed skim-milk A, or the per- 
centage of S. N. F. in the condensed skim-milk that is available 
for standardizing. Subtract the percentage of fat desired from 
the percentage of fat in the condensed milk. Call the remainder 
B, or the percentage of fat in the condensed whole milk that is 
available for standardizing. Subtract the percentage of S. N. F. 
desired from the percentage of S. N. F. in the condensed whole 
milk. Call the remainder C, or the percentage of S. N. F. in the 
condensed whole milk available for standardizing. 

(2.) Divide the percentage of fat in the batch by the ratio 
between the S. N. F. and the fat in the product desired. Subtract 
from the answer the percentage of S. N. F. in the batch and mul- 
tiply the remainder by the pounds of milk in the batch. Call an- 
swer T>, or the pounds of S. N. F. short. Subtract the S. N. F. 
that the batch should contain from the S. N. F. in the condensed 
whole milk. Divide D by the remainder. Call the answer E, or 
the pounds of condensed whole milk required. 

(3.) Multiply E by B. Divide the product by the ratio be- 
tween the S. N. F. and fat in the product desired. Divide the 
answer by A. Call the answer F, or the pounds of condensed 
skim-milk required to equalize the excess fat in the condensed 
whole milk. 

(4.) Multiply the pounds of milk in the batch before stand- 
prdizing, by the percentage of S. N. F. in the batch. Call the an- 
swer G, or the pounds S. N. F. in the batch. Multiply E and F by 
the S. N. F. test of each respectively, and add the two results. Call 
the answer H. Call the sum of G and H, I or the pounds of S. N. 
F. in the entire batch, after standardizing. Add to the pounds in 
the batch before standardizing, the sum of E and F. Call the an- 
swer J. Divide the answer into I. Call the answer K, or the per- 
centage of S. N. F. in the batch after standardizing with con- 
densed whole milk, and condensed skim-milk. Subtract from K 



212 Standardizing Evaporated Milk 

the percentage of S. N, F. in the product desired. Multiply the 
remainder by J, and divide the product by the percentage of S. N. 
F. desired. Call the answer K, or the pounds of water required. 

(5.) Add to the pounds of whole milk before standardizing, 
the sum of E, plus F, plus J. The answer will be the total pounds 
in the batch after standardizing. 

Solution of Problem 16, based upon Formula 14 : 

(1.) To calculate the pounds of condensed whole milk re- 
quired. 



[^■■] 



— Bi I D^ 
M— f — 



(f) 



(2.) To calculate the pounds of condensed skim-milk re- 
quired. 



U = 



{^^^^) 



Q 



(3.) To calculate the percentage of S. N. F. in the batch after 
adding the condensed whole and skim-milks. Note: S- now rep- 
resents the percentage of S. N. F. in the mixture. 

D^ + D- + L^ 
(4.) To calculate the pounds of water required. 



^^.^ (S^-A) X (D^ + D^ + L^) 



Problems After Condensing 
Problem 16, Example 17: 



213 



Products 


Pounds 


Per Cent 




Fat 


S. N. F. 


T. S. 


Evaporated milk 

Condensed whole milk .... 


10,000 


8.00 
t 10.50 


17.00 
25.50 
25.50 


25.00 
36.00 


Condensed skim-milk .... 






Water 








Composition desired 




7.80 


17.70 


25.50 









Solution of Problem 16, Example 17, based upon Rule 14: 

(1.) To calculate in the above two products the percentage of 
fat and the percentage of S. N. F. available for standardizing. 
25.50 = S. N. F. (the fat is disregarded), or total solids in con- 
densed skim-milk available for standardizing. 
10.50 — 7.80 = 2.70, per cent of fat in condensed whole milk 
available for standardizing. 

25.50 — 17.70 =: 7.80, per cent S. N. F. in condensed whole milk 
available for standardizing. 

(2.) To calculate the pounds of condensed whole milk re- 
quired. 

8.00-^.4407 = 18.15, per cent of S. N. F. that the evaporated 

milk should have. 
18.15 — 17.00 = 1.153, per cent of S. N. F. short. 
.0115X10000=115.3 pounds S. N. F. short. 
25.50 — 18.15 = 7.35, per cent of S. N. F. available for stand- 
ardizing in condensed milk. 
115.3-f-.0735 = 1568 pounds condensed whole milk required to 

provide the S. N. F. short. 
(3.) To calculate the pounds of condensed skim-milk re- 
quired. 

1568 X. 027=43, pounds of fat 'in excess over amount required 
in the condensed whole milk. 
43 -^ .4407 = 96, pounds of S. N. F. required to equalize the 
excess of fat in the condensed whole milk. 



214 Standardizing Milk and Cream 

96-f-.255=:377, pounds of condensed skim-milk required to 
equalize the excess fat in the condensed whole milk. 

(4.) To calculate the pounds of water required. 
10000 X .17=1700, pounds of S. N. F. in batch before stand- 
ardizing. 
(1568 + 377) X .255 = 496, pounds of S. N. F. in condensed whole 

milk and condensed skim-milk required. 
1700 -f 496 = 2196, pounds of S. N. F. in batch after adding con- 
densed whole milk and condensed skim-milk. 
10000 + 1568 4- 377 = 11945, total pounds in batch after adding 
condensed whole milk and condensed skim-milk. 
2196 ^ 11945 = 18.38, per cent S. N. F. in batch after adding 

condensed whole milk and condensed skim-milk. 
18.38 — 17.70 = .68, per cent S. N. F. in excess after adding con- 
densed whole milk and condensed skim-milk. 
11945 X .0068 = 82, pounds S. N. F. in excess. 
82 -^ .1770 := 463, pounds of water required. 
(5.) Material in batch after standardizing^. 
1568 pounds condensed whole milk. 

377 pounds condensed skim-milk. 
10000 pounds before standardizing. 
463 pounds water. 



12408 pounds total after standardizing. 

Solution of Problem 16, Example 17, based upon Formula 14: 

(1.) To calculate the pounds of condensed whole milk re- 
quired. 



II44077 J J 

\ .4407 / 



X 10000 



D = '-^ ^ --5- = 1568. 

.2550 — j 



(2.) To calculate the pounds of condensed skim-milk re- 
quired to standardize the excess of fat in the whole milk. 

/.105— .078)X1568.6\ 
\ 4407 J 



Problems After Condensing 



215 



(3.) To calculate the percentage of S. N. F. in the batch after 
adding the condensed whole and skim-milk. 

(10000X.17) + (1568X.2550) + (377X.2550) 

10000 + 1568 + 377 " 

(4.) To calculate the pounds of water required. 

(.1838— .177) X (10000+1568+377) 



W 



.177 



=463 



Proof of Problem 16, Example 17: 





Pounds 


Pounds 


Per Cent 


Products 


Fat 


S. N. F. 


T. S. 


Fat 


S. N. F. 


T. S. 


Evaporated milk. . 
Condensed whole 
milk 


10,000 

1568 

377 
463 

12,408 


800 
164.7 


1700 

400 

96 


2500 

564 

96 


8.00 
10.50 


17.00 
25.50 
25.50 


25.00 
36.00 


Condensed skim- 
milk 


25.50 


Water 




Standardized 
product 


964.7 


2196 


3160 


7.80 


17.70 


25.50 



STANDARDIZING EVAPORATED MILK AFTER CONDENSING. 

Problem 17: How to Calculate When Both Condensed Whole 
Milk and Cream Are Required for Standardizing : 
Solution of Problem 17, Based Upon Rule 15 : 

(1.) Subtract the percentage of fat desired from the percentage 
of fat in the cream. Call the an.swer A, or the percentage of fat in 
the cream available for standardizing. Subtract the percentage of 
S. N. F. in the cream from the percentage of S. N. F. desired. Call 
the answer B, or the percentage of S. N. F. short in the cream, un- 
der that desired. Subtract the percentage of fat desired from the 
percentage of fat in the condensed whole milk. Call the answer C, 
or the percentage of fat in the condensed whole milk available for 
standardizing. Subtract the percentage of S. N. F. desired from 
the percentage of S. N. F. in the condensed whole milk. Call the 
remainder D, or the percentage of S. N. F. in the condensed whole 
milk available for standardizing. 



216 Standardizing Milk and CrEam 

(2.) Subtract the percentage of fat in the batch from the per- 
centage of fat desired. Call the remainder E, or the percentage 
of fat short. Multiply the pounds of milk in the batch by E. Call 
the product F, or the pounds of fat short. Subtract the percen- 
tage of S. N. F. in the batch from the percentage of S. N. F. de- 
sired. Call the remainder G, or the percentage of S. N. F. short. 
Multiply the pounds milk in the batch by G. Call the product H, 
or the pounds of S. N. F. short. 

(3.) Divide H by the percentage of fat desired. Call the an- 
swer I, or the pounds of condensed whole milk required to provide 
the S. N. F. short in the batch. 

(4.) Multiply I by C. Call the product J, or the pounds fat 
available in the condensed whole milk added. Subtract J from E. 
Call the answer K, or the pounds fat to be provided by cream. 
Divide K by A. Call the answer L, or the pounds of cream re- 
quired to provide the fat short. 

(5.) Multiply L by B. Call the product M, or the pounds of 
S. N. F. short in the cream. Divide M by D. Call the answer 
N, or the pounds of condensed whole milk necessary to provide the 
S. N. F. required to standardize the cream added. 

(6.) Add to the pounds of milk in the batch before standard- 
izing the sum of I, L and N. The answer will be the total pounds 
in batch after standardizing. 

Solution of Problem 17, Based Upon Formula 15 : 

(1.) To calculate the pounds of condensed whole milk re- 
quired to provide the S. N. F. short in the evaporated milk. 

^.^^ [(B-B^)D^ ] 

A 
(2.) (To calculate the pounds of cream required to provide 
the fat short in the evaporated milk. 

Q^ [(A-K^) D^]-[(K-A) D--] 

G — A 
(3.) To calculate the pounds of condensed whole milk re- 
quired to provide the S. N. F. short in the cream. 

D2^ (B — J)0 
A 
Note: The sum of D- part (1) and D^ part (2) of the formula 
equals the total number of pounds of condensed whole milk used. 



pROBi^KMS After Condensing 
Problem 17, Example 18 : 



217 



Products 


Pounds 


Per Cent 




Fat 


S. N. F. 


T. S. 


Evaporated milk 

Condensed whole milk .... 


10,000 


7.36 
10.50 
40.00 

7.80 


17.46 

25.50 

5.00 

17.70 


24.82 
36.00 


Cream 




45.00 


Composition desired 




25.50 









Solution of Problem 17, Example 18, based upon Rule 15 : 

(1.) To calculate in the above two products the percentages 
of fat and S. N. F. available for standardizing. 

40 — 7.8 j=. 32.2, per cent, of fat in cream available for stand- 
ardizing. 

17.7 — 6.0 = 11.7, per cent of S. N. F. short in cream. 

10.50 — 7.80 ^ 2.70, per cent of fat in condensed whole milk 

available for standardizing. 
25.50 — 17.70= 7.80, per cent of S.N. F. in condensed whole 

milk available for standardizing. 

(2.) To calculate pounds of fat and S. N. F. short. 

7.80 — 7.36 = .44, per cent of fat short. 
10000 X. 44= 44, pounds of fat short. 
17.70 — 17.46 = .24, per cent of S. N. F. short. 
10000 X. 0024=24, pounds of S .N. F. short. 

(3.) To calculate the pounds of condensed whole milk re- 
quired to provide S. N. F. short in batch. 

24.0-^.078=308, pounds of condensed whole milk required to 

provide the S. N. F. short in the batch. 

(4.) To calculate the pounds of cream required: 

308 X .027= 8.3, pounds of fat available in condensed whole 

milk added. 
44 — 8.30 = 35.7, pounds of fat to be provided by cream. 
35.7-^-.322=;lll, pounds of cream required to provide the fat 

short. 



218 Standardizing M11.K and Cream 

(5.) To calculate the pounds of condensed whole milk re- 
quired to equalize the S. N, F. short in the cream added for stand- 
ardizing. 

Ill X. 117=13.0, pounds of S. N. F. short in cream. 
13.0-^-.078= 167, pounds of condensed whole milk necessary to 
provide the S. N. F. required to standardize the cream added. 



(6.) Material in batch after standardizing. 

308 pounds of condensed whole milk required by batch. 

167 pounds of condensed whole milk required by cream. 

Ill pounds of cream, 
10000 pounds before standardizing. 
10586 pounds total after standardizing. 

Solution of Problem 17, Example 18, Based Upon Formula 15 : 

(1.) To calculate the pounds of condensed whole milk re- 
quired to provide the S. N. F. short in the evaporated milk. 

(.177— .1746) X 10000 

^'= m =^"« 

(2.) To calculate the pounds of cream required to provide 
the fat short in the evaporated milk. 

[ (.078— .0736) XlOOOO] — [ (.1050— .078) X308]_ 
^ ^ .40— .078 ~ ^^^ 

(3.) To calculate the pounds of evaporated whole milk re- 
quired to provide the S. N. F. short in the cream. 

(.177— .06)X111 
°'= ^JTS ="^ 



Probi^ems Aft^r Conde:nsing 219 

Proof of Problem 17, Example 18: 



Products 


Pounds 


Pounds 


Per Cent 




Fat 


S. N. F. 


T. S. 


Fat 


S. N. F. 


T. S. 


Evaporated milk. . 
Condensed whole 
milk 


10,000 

475 
111 

10,586 


736 

50 

44 

830 


1746 

121 
61 

1873 


2482 

171 
50 

2703 


7.36 

10.50 
40.00 

7.83 


17.46 

25.50 
6.00 

17.69 


24.82 
36.00 


Cream 


46.00 


Standardized 
product 


25.52 



The surplus fat in the condensed whole milk added to stand- 
ardize the cream was disregarded in the calculation. This method 
does not give absolutely correct standardization but the results 
are within very narrow limits of those desired. 



CHAPTER XII 

STANDARDIZING SWEETENED 
CONDENSED MILK 

The principles underlying the standardization of sweetened 
condensed milk are very similar to those underlying the standard- 
ization of evaporated milk, namely, mixing together fat, milk 
S. N. F. and in addition sucrose obtained from either cane or beet 
sugar, in the ratio one to the other that these are to occur in the 
finished product which it is desired to manufacture. These ratios 
can be obtained upon any desired composition of product by di- 
viding the percentage of one constituent into the percentage of 
another constituent of the standard product. Table 32 contains 
these ratios in the case of a product testing 8.00 per cent of fat, 
20.00 per cent of milk S. N. F. and 44.50 per cent sucrose, and also 
in the case of sweetened condensed skim-milk. 

Theoretically it would be possible under certain conditions to 
standardize sweetened condensed milk after condensing. How- 
ever, the possibilities for trouble under conditions of this kind are 
so numerous that it is deemed best not to encourage the practice 
at the present stage of our knowledge. The practice of standard- 
izing before condensing is a simple and a logical one, and this will 
be fully discussed in this chapter. 

Under the older methods the standardization is, as a rule, crude 
and inefficient, and concerns itself chiefly with obtaining a prod- 
uct either of a certain fat or of a certain T. S. test. The method 
commonly used is to add a certain number of pounds of sugar for 
every 'one hundred pounds of whole milk that go to make up the 
batch. Sometimes the ratio of pounds of sugar to pounds of milk 
is varied with the season of the year, the range being in the case 
of whole milk, from 18 to 20 pounds. Under this method, the re- 
sulting product varies greatly both in chemical composition, and 
in its physical properties. 

[220] 



SwEETEiNED Condensed Milk Constants 

TABLE 32. 

Constants for Sweetened Condensed Milk. 



221 





Product from 


Constants. 


WlioIe 
milk. 


Skim- 
milk. 


Percentage fat. Federal standard 


8.00 
20.00 
28.00 

3.5000 


None 


Percentage S. N. F. Federal standard 


28.00 


Percentage T. S. Federal standard 


28.00 


Ratio percentage fat to percentage milk solids . . . 


None 


Ratio percentage fat to T. S. (8.00 per cent fat to 






72.5 per cent T. S.) 


9.06 


None 


Ratio percentage fat to percentage milk S. N. F . . 


2.5000 


None 


Ratio percentage milk S. N. F. to percentage fat . . 


.4000 


None 


Ratio percentage milk S. N. F. to percentage T. S. 


1.4000 


None 


Ratio percentage total milk solids to percentage 






fat 


.2857 


None 


Ratio percentage sugar to percentage fat, using 




44.50 per cent sugar 


.1798 


None 


Ratio percentage sugar to percentage total milk 






solids, using 44.50 per cent sugar 


.4493 


None 


Ratio percentage sugar to percentage total milk 




solids, using 42.00 per cent sugar 




.6667 







Under the methods given in this chapter, the aim is to stand- 
ardize the sweetened condensed milk upon the triple basis of fat, 
milk S. N, F. and sucrose. This makes possible a product of uni- 
form chemical composition and physical properties, at all times, 
other things being equal. 

SUCCESSIVE STEPS IN STANDARDIZING SWEETENED CON- 
DENSED MILK. 

The steps involved in standardizing sweetened condensed milk 
are as follows : 

(1.) Obtaining a representative composite sample of the en- 
tire lot of whole milk which goes to make up the batch ; likewise 
the skim-milk, cream or other product which might be used in 
standardizing, 

(2.) Testing of all the above products involved for both fat, 
S. N. F. or T, S. by means of the Mojonnier Milk Tester. In the 
case of the S. N. F. in the cream, it usually suffices to obtain the 
S. N. F. from Table 22, inasmuch as the amount is not large. 



222 Standardizing Sweetened Condensed Milk 

(3.) Calculating the weight of each product to be used by 
methods which will follow, in order to make the fat, the milk 
S. N. F. and the sugar in the initial product of the same ratio as 
these are to occur in the case of the finished product. 

(4.) When the initial product has been standardized so that 
the fat, the milk S. N. F. and the sugar are in the required ratio, 
the same is to be condensed down to the desired specific gravity to 
yield a finished product of the test required. In practice, it is 
well to condense the batch to a little higher concentration than 
desired, in order to provide the necessary factor of safety. If the 
concentration of the batch should be less than the required con- 
centration, it becomes necessary either to recondense part of the 
batch, or to condense another batch to add to it, provided the 
facilities are at hand for thoroughly mixing the two batches. It 
is not recommended at this stage of our knowledge of the sweet- 
ened condensed milk business to add water to the batch in case 
it is overcondensed. Under some conditions, it may be possible 
to add condensed skim-milk, but this is not very often practicable 
unless this can be added to the milk in the pan instead of to the 
milk in the mixing tanks after cooling. At the present time the 
only method that is recommended for correcting improper con- 
densing is by mixing together the batch that is improperly con- 
densed with another batch that is condensed in the proper way to 
correct the error in the case of the first batch. 

METHOD OF COLLECTING COMPOSITE MILK SAMPLES. 

No fixed method of sampling is recommended that can be ap- 
plied to meet all the varying conditions of different plants. This 
important matter will need careful study in each plant, in order 
to determine the procedure that will give the most accurate sam- 
ples. The reader is referred to Chapter VI for complete informa- 
tion upon this point. 

METHOD OF TESTING. 

Use the Mojonnier Tester for making all fat and T. S. deter- 
minations upon all products used in standardizing. The skim- 
milk and cream should be tested before the composite sample of 
the whole milk reaches the laboratory. The S. N. F. in the cream 
can be obtained from Table 22 as the total amount of the same is 



Order of OpERAtioNS 223 

usually small, so the possibility for error that may result on ac- 
count of not making actual determinations of S. N. F. is a very 
negligible one. As it is necessary to complete the fat and T. S. 
tests of the whole milk while the last forewarmer is being heated 
and drawn into the pan, these tests should be made as rapidly as 
possible. A short time before the sample is ready, the tempera- 
ture of the hot plates and ovens upon the Mojonnier Milk Tester 
should be regulated ; fat and T. S. dishes cooled and weighed ; 
clean glassware and a weigh cross prepared for use, and every- 
thing put in readiness for making the test. By systematizing 
the successive steps, the time for completing the fat and T. S. 
tests, including the total time for making the calculations, should 
not exceed twenty-five or thirty minutes, counting from the time 
the sample reaches the laboratory. Under some conditions, it 
may be desirable to give the operator a helper, while making the 
tests, as this will greatly expedite the operations. 

ORDER OF OPERATIONS IN STANDARDIZING SWEETENED CON- 
DENSED MILK REFORE CONDENSING, USING 
MOJONNIER TESTER. 

(1.) Test, as far in advance as possible, the cream samples for 
fat. Obtain the S. N. F. test of the cream from Table 22. If 
skim-milk, sweetened condensed skim-milk, or sweetened con- 
densed whole milk are to be used for standardizing, test each of 
these products for both fat and T. S. as far in advance as pos- 
sible. 

(2.) About half an hour before the composite whole milk sam- 
ple is ready, do everything necessary to begin making the fat and 
T. S. test of the whole milk. It is recommended that the tests be 
made in duplicate. If the operator is very careful in his work, a 
single determination may suffice. 

(3.) Keep the fat and the T. S. dishes in the respective ovens 
for five minutes under proper heat, and with the vacuum on. 

(4.) Transfer the dishes from the ovens to the cooling desic- 
cators. Keep the water circulating. Weigh the T. S. dish with 
the cover on, at the end of five minutes ; and the fat dish alone at 
the end of seven minutes. Record weights and numbers upon the 
laboratory report. 



224 Standardizing Sweetened Condensed Miek 

(5.) As soon as the composite whole milk sample reaches the 
laboratory, mix the same thoroughly by pouring back and forth at 
least six times using two vessels. 

(6.) Fill the two gram pipette to the mark and transfer the 
milk to the previously weighed dish, and weigh the dish with the 
milk immediately. Or, if preferred, the sample in the two gram 
pipette can be weighed from the weigh cross. 

(7.) While the operator is weighing the sample, as directed 
under 6, the second operator pipettes out ten grams into the but- 
terfat extraction flask. 

(8.) One operator now prepares the T. S. sample for the T. S. 
oven, and the second operator the fat sample for the fat oven. 
Dishes and contents are heated in ovens, cooled in cooling desic- 
cators and weighed in accordance with the directions. 

(9.) Calculate the percentage of fat and the percentage of 
T. S. and transfer the results to the sweetened condensed milk re- 
port blank. 

(10.) Calculate the pounds of material to add, using the rule 
that may apply, selecting the proper one beginning with Rule 16, 
and ending with Rule 23. The sugar to be used can be ascertained 
by referring to Table 32. 

(11.) Test the finished product for fat and T. S. and enter 
the result upon the sweetened condensed milk report. 

(12.) Divide the percentage of T. S. by the percentage of fat 
to get the ratio of fat to T. S. in the finished product. 

(13.) If the condensation is not otherwise obtained, divide 
the percentage of T. S. in the finished product by the percentage 
of T. S. in the initial product, or divide the percentage of fat in 
the finished product by the percentage of fat in the initial product. 

(14.) Divide the total pounds of raw products used by the 
condensation to obtain the pounds in the batch after condensing. 
Or, obtain the pounds in the batch by weighing the same in a suit- 
able tank as it comes from the pan; 

(15.) Calculate the pounds of raw milk products per case, 
likewise the pounds of sugar per ease. 



SwEKTENKD MtI.K RrpORT 



225 



SWEETENED MILK REPORT 



I 



BLANK FOR RECORDING THE STANDARDIZING DATA. 

It is very important to keep a systematic record of all data in 
connection with the standardization of any given batch. A blank 
especially designed for this purpose is illustrated under Fig. 69. 

METHOD OF GETTING WEIGHTS. 

The person who does the standardizing should be sure that the 

pounds of whole milk, likewise the pounds of cream and skim-milk 

used, are correctly re- 
ported and properly 
checked. If this part 
of the work is not prop- 
erly done, large errors 
may be introduced in 
the work. 

The pounds of fin- 
ished product should be 
correctly ascertained. 
The methods suggested 
in Chapter XI, for get- 
ting the weight of the 
finished batch of evap- 
orated milk can be 

applied with a few modifications to sweetened condensed milk. 

Where possible the weight of each batch as the same is dropped 

from the pan, should be obtained. 

HOW TO CALCULATE THE POINT AT WHICH TO STRIKE THE 
BATCH IN THE PAN. 

On account of the impossibility of correcting for overconden- 
sation, as in the case of evaporated milk, the striking point upon 
sweetened condensed milk requires most careful watching. Ex- 
act knowledge is necessary as to just what striking point is re- 
quired to produce a certain concentration of product. 

Table 35 gives the specific gravity at different temperatures 
of sweetened condensed milk in which the constituents are in the 
following ratio : 8.00 per cent of fat, 20.00 per cent of milk 
S. N, F., 44.50 per cent of sucrose and 72.50 per cent of T. S. The 
actual composition was 8.05 per cent fat, 20.13 per cent of milk 
S. N. F. and 73.00 per cent of T. S. 



"■S" 


'Z 


:e 


"J^*" 


s^: 


.JiR, 


"^"1 ^sJ 


ir 


SiH" 


"iP 


(Mo, 


"■•'— 










'^ 1 










MOOUCn USED 


"- 


^.. 


.«,. 


'^S" 


TvulKlblt 




"""^resjuS?" "-' 


»MDMTAIHU> 


i^.». 


"■- 


T^,^ 


,^^_„ 




















I..^ <«_.>. 








































>._~l._ 




















Mi. «_....«. 


















':sr;.'^— " 
















'sti-s 


.»(...»■ 


... 


z-z 


^B 


iir^ 


%58«r 


W 


-"."•" r-.-- 


"rt flN 






Twllt. .!]..-....«,. 


Ml««m«. 




»»d-CI 


.^..1 








'"tl.iSlrt.^V"" ' 


Brt„ «'«tartttlM 




--atrsrsiK. 


















"iS-SKiS'-uSi 












's^.t.'s;:— -"H 


A..., «.J«.^..»., 




SS£Si'™^"Kli 










^sr.'j.risr- 




o.t 


, 


o> 



















Fig-. 69. 
Blank Beport for Sweetened Condensed Milk. 



226 



Standardizing Sweetened Condensed Milk 



TABLE 33, 

Specific giavity at various temperatures of sweetened condensed whole 
milk testing 8.00 per cent of fat; 20.00 per cent of milk S. N. F., and 72.50 
per cent of T. S. Sample furnished by Carnation Milk Products Co. Tests 
made by J. A. Cross and H. J. Liedel. 



Temper- 
ature °F. 


Specific 
Gravity 


Degrees 
Baume 


Degrees 
Twaddell 


Temper- 
ature °F. 


Specific 
Gravity 


Degrees 
Baume 


Degrees 
Twaddell 


40 


1.3157 


34.8 


63.14 


110 


1.2881 


32.4 


57.62 


60 


1.3065 


34.0 


61.30 


120 


1.2853 


32.2 


57.06 


80 


1.2986 


33.3 


59.72 


130 


1.2818 


31.9 


56.36 


100 


1.2918 


32.8 


58.36 


140 


1 . 2789 


31.6 


55.78 



Based upon the foregoing table, the unit temperature and spe- 
cific gravity relation in sweetened condensed whole milk of the 
test indicated is as shown in Table 34. 



TABLE 34. 

Unit relation of temperature to specific gravity in sweetened condensed 
whole milk testing 8.00 per cent fat; 20.00 per cent M. S. N. F., and 72.50 
per cent T. S. 



Temperature Range 


Decrease in specific gravity (or vice versa 
F. increase in temperature. 


) , for each degree 




Specific Gravity 


Baume 


Twaddell 


40° to 80° F 


.00043 


.038 


.085 


80° to 110° F 


. 00035 


.030 


.070 


110° to 140° F 


.00030 


.027 


.060 



The above relation can be used to advantage in reducing spe- 
cific gravity to a definite temperature, when striking the batch at 
the pan. 

Example : — Baume reading at 135° F. is 31.75. What is the 
Baume reading at 130° F.? 

135 — 130=5, degrees F. over standard desired. 

.027 X 5 =.135, degree Baume to be added to reading. 
31.75+.135=31.9, the 135° F. Baume reading reduced to 130° F. 



Specific Gravity and Composition 



227 



RELATION BETWEEN SPECIFIC GRAVITY AND COMPOSITION 
IN SWEETENED CONDENSED WHOLE MILK. 

Whenever it may be necessary to change the composition of a 
given batch of svreetened condensed milk, it is important to knov^ 
the relation between specific gravity and composition so that the 
striking point of additional batches may be so altered as to yield 
a mixed product of the desired test. Table 35 gives this relation 
in the case of a product in which the constituents are in the ratio 
8.00 per cent fat, 20.00 per cent of milk S. N. F., 44.50 per cent 
of sucrose and 72.50 per cent of T. S. 



TABLE 35. 

Relation Between Specific Gravity and Composition in Sweetened 
Condensed Whole Milk. 



i 



Composition 


At 60° F. 


At 100° F. 


At 120° F. 


At 140° F. 


si 

p. t- 
coo 


01 

e 

3 
03 




030 


01 

e 

3 
01 

m 


•a — 


'p 

p. u. 
OQO 


i 

3 
0! 

m 


■0 — 


fOO 


a 

B 

3 
« 


113 


73.00 T. S. 
20.12 M.S.N.F. 
8.05 fat 


1.3087 


34.2 


61.74 


1.2947 


33.0 


58.94 


1.2883 


32.5 


57.76 


1.2819 


31.9 


56.38 


72.50 T. S. 
20.00 M.S.N.F. 
8.00 fat 


1.3065 


34.0 


61.30 


1.2918 


32.8 


58.32 


1.2853 


32.2 


57.06 


1.2789 


31.6 


55.78 


71.25 T. S. 
19.66 M.S.N.F. 
7.86 fat 


1.3044 


33.8 


60.88 


1.2888 


32.5 


57.76 


1.2826 


31.9 


56.52 


1.2753 


31.3 


55.06 


70.00 T. S. 
19.33 M.S.N.F. 
7.73 fat 


1.2988 


33.4 


59.76 


1.2842 


32.1 


56.84 


1.2778 


31.5 


55.56 


1.2699 


30.8 


53.98 


68.75 T. S. 
19.06 M.S.N.F. 
7.59 fat 


1.2923 


32.8 


58.46 


1.2787 


31.6 


55.74 


1.2724 


31.0 


54.48 


1.2651 


30.4 


53.02 


67.50 T. S. 
18.63 M.S.N.F. 
7.45 fat 


1.2857 


32.2 


57.14 


1.2728 


31.1 


54.56 


1.2665 


30.5 


53.30 


1.2599 


29.9 


51.99 


66.25 T. S. 
18.28 M.S.N.F. 
7.31 fat 


1.2793 


31.7 


55.86 


1.2673 


30.6 


53.46 


1.2601 


29.9 


52.02 


1.2541 


29.4 


50.82 



From the above table it is ascertained that a difference of .10 
degrees Baume is equal to about .27 per cent of T. S. in the case 
of sweetened condensed whole milk of the above composition. 



228 



Standardizing SwfiETiiNED Condensed Milk 



This information is applied in practice as shown by the follow- 
ing example : The condensed milk in the standardizing tank 
weighs 35,100 pounds and tests 8.22 per cent of fat and 74.50 per 



KEY TO FIG. 70 



Curve 


1 


2 


3 


4 


5 


6 


7 


Fat per cent . . . 


7.45 


7.55 


7.72 


7. 86 


7.94 


8.00 


8.05 


Sugar per cent . 


41.43 


42.23 


42.96 


43.74 


44.20 


44.50 


44.83 


Total Solids per 
cent 


67.50 


68.75 


70.00 


71.25 


72.00 


72.50 


73.00 




V/rr/N DEGREE5 BAUME 



Piff. 70. Relation between temperature, specific gravity and composition 
in the case of sweetened condensed milk in which the ratio bei'ween M. S. TX. F. 
an4 fat is as 1 to .40, Results obtained by J. A. Cross and K. J. I^iedel, 



Specific Gravity and Composition 



229 



cent of T. S. The test desired is 8.11 per cent of fat and 73.50 per 
cent of T. S. 74.50 — 73.50 = 1.00 per cent of T. S. in excess 
of that required. 35100 X 1.00 per cent = 351, or pounds of 
T. S. that are overcondensed. The milk in the last pan batch 
available should yield normally about 5700 pounds of condensed 
milk testing 73.50 per cent of T. S., and 34.4° Baume at 140° F. 
Since .10 degree Baume varies the T. S. test .28 per cent, upon 
5700 pounds the variation would be equivalent to 15.96 pounds 
of T. S. per .10 degree Baume. Dividing 351 by 15.96 equals 22.0, 
or the number of .10 degree Baume necessary to deduct from the 
normal striking point of the last pan batch, namely 34.4"^ Baume. 
Therefore 34.4 — 2.20 = 32.2° Baume, or the striking point upon 
the last batch, necessary to make the correction desired. 

The graph under Fig. 70 gives the composition, temperature 
and specific gravity in Baume degrees, in the case of sweetened 
condensed whole milk of the composition named above. This 
graph can be used within its limits to find the composition at any 
given Baume test, and temperature ; or vice versa, the Baume test 
at any given composition and temperature. 

RELATION BETWEEN SPECIFIC GRAVITY AND COMPOSITION 
IN SWEETENED CONDENSED SKIM-MILK. 

The above relation, expressed in several ways, is given in 
Tables 36 and 37, and by graph under Fig. 71. The values given 
are based upon careful and accurate pycnometer determinations, 
under exact temperature control. 



TABLE 36. 

Specific gravity sweetened condensed skim-milk testing .50 per cent fat, 
27.50 per cent M. S. N. F., and 70.00 per cent T. S. Tests made by J. A. 
Cross and H. J. Liedel. 



Temper- 
ature °F. 


Specific 
Gravity 


Degrees 
Baume 


Degrees 
Twaddell 


Temper- 
ature °F. 


Specific 
Gravity 


Degrees 
Baume 


Degrees 
Twaddell 


40 


1.3483 


.37.5 


69.66 


110 


1 . 3306 


.36.0 


66.12 


60 


1 . 3436 


37.111 


68.72 


120 


1.3265 


35.7 


65.30 


80 


1 . 3386 


36.7 


67.72 


130 


1.3232 


35 4 


64.64 


100 


1 . 3328 


36.3 


66.56 


140 


1.3198 


35.1 


63.96 



230 



Standardizing Sweetened Condensed Milk 



TABLE 37. 

The relation between specific gravity and composition in sweetened con- 
densed skim-milk testing in the ratio of .50 per cent fat; 27.50 per cent M. S. 
N. F., and 70.00 per cent T. S. Tests made by J. A. Cross and H. J. Liedel. 





AT 60° F. 


AT 100° F. 


Per Cent T. S. 


Specific 
Gravity 


°Baume 


"Twaddell 


Specific 
Gravity 


°Baume 


"Twaddell 


70.0 


1.3436 


37.1 


68.72 


1.3328 


36.3 


66.56 


68.0 


1.3329 


36.3 


66.58 


1 . 3227 


35.4 


64.54 


65.0 


1.3134 


34.6 


62.68 


1.3035 


33.8 


60.70 


60.0 


1.2836 


32.0 


56.72 


1.2735 


31.1 


54.70 


55.0 


1.2588 


29.8 


51.72 


1 . 2480 


28.8 


49.60 


50.0 


1 . 2284 


27.0 


45.68 


1.2180 


25.9 


43.60 



















AT 120° F. 


AT 140° F. 


Per Cent T. S. 


Specific 
Gravity 


°Baume 


°TwaddeIl 


Specific 
Gravity 


°Baume 


°Twaddell 


70.0 


1.3265 


35.7 


65.30 


1.3198 


35.1 


63.96 


68.0 


1.3175 


34.9 


63.50 


1 . 3099 


34.3 


61.98 


65.0 


1.2968 


33.2 


59.36 


1.2896 


32.6 


57.92 


60.0 


1.2683 


30.7 


53.66 


1.2612 


30.0 


52.24 


55.0 


1.2419 


28.2 


48.38 


1 . 2355 


27.6 


47.10 


50.0 


1.2119 


25.3 


42.38 


1 . 2060 


24.8 


41.20 










' 


1 



From the above table it is ascertained that a difference of .10 
degree Banme is equal to about .20 per cent T. S. in the case of 
sweetened condensed skim-milk of the composition given. Prac- 
tical application of this fact is made as follows : The condensed 
milk in the standardizing tank weighs 10,000 pounds, and tests 



Specific Gravity and Temperature 



231 



69.00 per cent T. S. The test desired is 70.00 per cent T. S. 70.0 
— 69.0 = 1.00 per cent of T. S. short of that required. 10,000 X 
.01=100 pounds of T. S. short. The condensed product from 
the last batch should yield normally about 5,000 pounds, testing- 
70.0 per cent of T. S. and 34.7° Baume at 140^ F. Since .10 Baume 
varies the T. S. test .20 per cent, upon 5000 pounds this variation 
would be equivalent to 10.0 pounds of T. S. per .10 degree Baume. 
(100 -f- 10) X -10 = 1.0 degree Baume necessary to add to the 
normal striking point. Therefore 34.7 -(- 1.0 = 35.7 or the strik- 
ing point upon the last pan batch necessary to make the correction 
desired. 

Based upon the foregoing tables, the unit temperature and 
specific gravity relation in sweetened condensed skim-milk of the 
test indicated, is given in Table 38. 

TABLE 38. 
Unit relation of temperature to specific giavlty in sweetened condensed 
skim-milk testing .50 per cent fat, 27.50 per cent milk S. N. F. and 70.00 per 
cent T. S. 



Temperature range. 


Decrease in specific gravity (or >ice 

versa) for each degree F. increase 

in temperature. 


Specific 
gravity. 


Baume. 


Twaddell. 


40° to 80° F 


.00025 
.00027 
.00036 


.020 
.020 
.020 


.050 


80° to 110° F 


.054 


110° to 140° F 


.072 







The above relation can be used to advantage in reducing spe- 
cific gravitj^ to a definite temperature when striking the batch at 
the pan. 

Example : Baume reading at 120° F. is 35,7. What is the 
Baume reading at 125° F. ? 

125 — 120= 5, degrees F. over standard desired, 

5X-03:= ,15, degree Baume to be deducted from the read- 
ing at 120° F. 
35.7— .5=35.55, the Baume reading at 120° F. 

The graph under Fig. 71 gives the composition, temperature 
and specific gravity relation in Baume degrees in the case of 
sweetened condensed skim-milk of the composition named above. 



232 



Standardizing Swektknkd Condensed Mii^k 



This graph can be used within its limits to find the composition at 
any given Baume test and temperature ; or vice versa, the Baume 
test at any given composition and temperature. 

KEY TO FIG. 71 



Curve 


1 


2 


3 


4 


5 


6 


Fat per cent 


.36 


.39 


.43 


.46 


.48 


.50 


Sugar per cent 


30.00 


33.00 


36.00 


39.00 


40.80 


42 00 






Total Solids per cent. . . . 


50.00 


55.00 


60.00 


65.00 


68.00 


70.00 




SPECIFIC GRA 



Fig*. 71. Relation specific gravity and composition in sweetened condensed 
ekim-niilk in which the constituents are in following" ratio: .50 fat, 42.00% 
sugar, 70.00% total solids. Tests made by J. A. Cross and H. J. Iiiedel. 




Equipment 233 

HOW TO STRIKE THE PAN BATCH. 

The method of striking sAveetened condensed milk is very sim- 
ilar to that given in Chapter XI for striking evaporated milk. 

The hydrometer most commonly used has a range of 26 to 37 
graduated into tenths upon the Baume scale. This corresponds 
to 1.2185 to 1.3426 upon the specific gravity scale. 

Another common method consists in the use of a pycnometer 
cup such as illustrated under Fig. 72. The cup is designed for 
a narrow limit of volume adjustment. The weight 
of the cup filled with the condensed product varies 
with the specific gravity of the product, and the 
condensation is continued until the desired weight 

Pig. 72. is obtained. 

Pycnometer Cup. 

IMPROVED METHOD AND EQUIPMENT FOR MANUFACTURING 
SWEETENED CONDENSED MILK. 

For plants handling 10,000 pounds or more of whole milk to 
be manufactured into sweetened condensed milk, the use of the 
equipment illustrated under Fig. 73 will make it possible to man- 
ufacture the best possible quality of product. The complete unit 
is furnished in standard sizes and capacities to meet various 
requirements. Table 39 lists the principal standard sizes, with 
capacities based upon a ten-hour working day. The capacities 
can be increased by increasing the hours of operation. 

The different items making up the system are placed in the 
proper relation one to the other to best facilitate the handling of 
the condensed product. From the vacuum pan the condensed prod- 
uct flows by gravity into a weigh tank set upon a scale where the 
weight of the batch is obtained. From the drop tank the milk is 
pumped by means of a high pressure pump through a coil cooler, 
and from there it discharges into standardizing tanks set pre- 
ferably upon the second floor. These tanks are fitted with spe- 
cially designed power agitators, and they are of such size as to 
hold the condensed product from at least an entire day's run. 



234 Standardizing Sweetened Condensed Milk 

TABLE 39. 

Capacities and Sizes of Standard Equipment for Manufacturing Sweetened 
Condensed Milk, Using the Mojonnier Process, 



■^ d 


B 

3 
3 

« s 

|.2 
(S a 
P a 


Capacity of vacuum 
J"* pan in pounds of 
g sweetened condensed 
§ 1 whole milk per hour 


O J, 

to 


Size of Hydraulic 
Pressure Pump 


Capacity of sweetened 
condensed milk Cooler 
in lbs. of sweetened 
condensed milk 
cooled per hour 


be a 

d 03 


0.2 
£12 


6 
tti.S 

"to M 

ill 

5 &.S 


(U 

73 

a 

'S3 <" 
• o J= 

I-.2 

iSe.s 




o d 
■35° 

0,T3 M 


10,000 to 
15,000 


50 


300 


12 


2 


12 


3,000 


500 


15,000 to 
25,000. .. 


60 


1,500 


400 


12 


2 


12 


3,000 


1,000 


25,000 to 
40,000... 


72 
78 


2,650 
2,950 


800 
800 


14 
14 


3J^ 

33-^ 


12 
12 


6,000 
6,000 


1,500 
1,500 


40,000 to 
75,000. .. 


84 


3,350 


1,000 


14 


3M 


12 


6,000 


3,000 


75.000 to 
125,000. . 


84 


3,350 


1,000 


14 


3M 


12 


6,000 


5,000 



The advantages of this system over all other methods for 
handling sweetened condensed milk are briefly as follows : 

(1) The condensed product is not exposed to the air between 
the vacuum pan and the filling machines, thus helping to prevent 
mold growth. 

(2) The method of agitation used makes it possible to obtain 
a finished product with small milk sugar crystals, rendering it 
smooth to the taste and helping to prevent the settling of the milk 
sugar upon the bottom of the cans. 

(3) Control of the composition between closer limits than is 
possible by any other method. 

Figs. 76, 77 and 78 illustrate three other types of sweetened 
condensed milk coolers that are in common use. 



Equipmknt 



235 



^\nS\\\\ \\\\\\\\v^^^^^^ 




2 b 



I 



236 



Standardizing Sweetenkd Condensed Mii,k 
















rifif. 74. 

Milk Sugar Crystals In Sweetened, Condensed Milk of Good Crystalline 
Quality. By Miss Iiucy Klein. Magnified 100 Diameters. 
















Pig. 75. 

Milk Sugar Crystals in Sweetened, Condensed Milk of Poor Crystalline 
Quality. By Miss Iiucy Klein. Magnified 100 Diameters. 



Fig. 74 is a photomicrograph of milk sugar crystals in sweet- 
ened condensed milk of good crystalline quality, that is, one that 
is smooth to the taste. Fig. 75 is a photomicrograph of sweetened 
condensed milk of poor crystalline quality. The latter product 
is of low commercial value, and is one in which the milk sugar is 
very likely to deposit upon the bottom of the containers. 



SWERTENI-D CONDI-NSKD MiLK CoOI<r^RS 237 




rigf. 76. 



Pig. 76. Sweetened Condensed Milk Cooler. 

Courtesy Creamery Package Mfg. Co. 




Tig 77. Sweetened Condensed Milk Cooler, 

Courtesy Manning Mfg. Co. 



238 



Standardizing Swektknkd Condensed Milk 




riff. 78. 



Tig. 78. Sweetened Condensed Milk Cooler. 

Courtesy Jensen Creamery Machinery Co. 

THE USE OF TABLES IN SHORTENING CALCULATIONS. 

Properly prepared tables can be used to save much time in 
making the standardizing calculations upon sweetened condensed 
milk. Tables can be prepared to cover any composition of prod- 
uct that it may be desired to manufacture. This chapter con- 
tains tables for a product having a composition of 8.00 per cent of 
fat, 20.00 per cent of milk S. N. F. and 44.50 per cent of sucrose, 
making 72.50 per cent of T. S. These are the minimum values, 
and it is recommended in practice to condense the product suffi- 
ciently to yield a product of the following test : 
8.10 per cent of fat. 

20.25 per cent of milk S. N. F. 

45.05 per cent of sucrose. 

73.40 per cent of T. S. 



Standardizing Tables 



239 



By following the above practice the finished product contains 
each constituent in the proper ratio one to the other, and in suffi- 
cient amounts to provide the necessary factor of safety. 

Sweetened condensed milk of various compositions is manufac- 
tured. The Federal Standard calls for a minimum of 8.00 per 
cent of fat and 20.00 per cent of milk S. N. F., but the content of 
sucrose is not governed by law. The composition just given is 
that recommended when the product is put up in tin cans for 
household use. 

Partly skimmed sweetened condensed milk is manufactured in 
large quantities, the same being marketed in barrels. The com- 
position recommended for this product is given in Table 40. 

TABLE 40. 

Composition of Partly Skimmed Sweetened Condensed Milk. 



Constituents. 


Minimum standard 

no factor of 

safety. 


Standard recom- 
mended, includ- 
ing proper fac- 
tor of safety. 


Fat 


5.00 
23.00 
44.00 
72.00 


5.10 


Milks. N. F 

Sucrose 


23.46 

44.88 


T. S. 


73.44 



Sweetened condensed skim-milk is marketed largly in bar- 
rels. The composition recommended for this product is given in 
Table 41. 

TABLE 41. 

Composition of Sweetened Condensed Skim-milk. 



Constituents. 


Minimum standard 

no factor of 

safety. 


Standard recom- 
mended, includ- 
ing proper fac- 
tor of safety. 


Milk solids 


28.00 
42.00 
70.00 


28.20 


Sucrose 


42.30 


T. S 


70.50 







240 Standardizing Sweetened Condensed Milk 

Table 42 gives the percentage of fat and milk S. N. F. in the 
proper ratio one to the other. The range is from .01 to 8.99 per 
cent of fat, and .03 to 22.48 per cent of milk S. N. F. It also 
gives the pounds of sugar to use for any corresponding pounds 
of fat from 6 to 5000. 

The table can be used in several different ways, as follows : 

(1.) To determine the per cent of S. N. F. required to stand- 
ardize the fat in any given skim-milk. 

Example : Skim-milk tests .16 per cent of fat. Reference to 
the table shows that .40 per cent of S. N. F. is required to stand- 
ardize .16 per cent of fat. 

2. To determine the per cent of fat required to standardize 
the S. N. F. in any given cream. 

Example : Cream tests- 7.10 per cent of S. N. F. Reference to 
the table shows that 2.84 per cent of fat are required to stand- 
ardize 7.10 per cent of S. N. F. 

(3.) To determine the per cent S. N. F. required to standard- 
ize the fat in any given whole milk, or vice versa. 

Example : Whole milk tests 4.00 per cent of fat. Reference to 
the table shows that 10.00 per cent of milk S. N. F. are required 
to standardize 4.00 per cent of fat. 

(4.) To determine the pounds of sugar required for any given 
size of batch. 

Example : The total pounds of fat in the whole milk and in 
the cream used to make up the batch amounts to 640 pounds. 
Turn to the table under percentage of f^t ; disregard the decimal 
point and consider the percentage as a whole number. The 
amount in the sugar column opposite 6.40 is 3554, or the pounds 
of sugar required for the total batch. 



Standardizing Tables 



241 



TABLE 42. 



Percentage of fat, S. N. F. in the proper ratio to standardize sweetened 
condensed milk upon the basis of 8.00 per cent of fat, 20.00 per cent of milk 
S. N. F., and 44.50 per cent of sugar. Also the pounds of sugar to use for any 
given number of pounds of fat. Ratios are as follows: 1 milk S. N. F. to 
.40 fat; 1 fat to 5.75 sugar, and 1 sugar to .1798 fat. 



Per C»nf 
Fat 


Per Cent 
Milk 

S. N.F. 


Lbs. Sugar to 
use for cor- 
responding 
wt. of Fat 


Per Cent 
Fat 


Per Cent 

Milk 
S. N.F. 


Lbs. Sugar to 
use for cor- 
responding 
wt. of Fat. 


Per Cent 
Fat 


Per Cent 
Milk 

S. N. F. 


Lbs. Sugar to 
use for cor- 
responding 
wt. of Fat 








.36 
.37 


.90 
.93 


200 
206 


.72 

.73 


1.80 
1.83 


400 


.01 


.03 


6 


408 


.02 


.05 


11 


.38 


.95 


211 


.74 


1.85 


412 


.03 


.08 


17 


.39 


.98 


217 


.75 


1.88 


417 


.04 


.10 


22 


.40 


1.00 


222 


.76 


1.90 


423 


.05 


.13 


28 


.41 


1.03 


228 


.77 


1.93 


428 


.06 


.15 


33 


.42 


1.05 


234 


.78 


1.95 


434 


.07 


.18 


39 


.43 


1.08 


239 


.79 


1.98 


439 


.08 


.20 


44 


.44 


1.10 


245 


.80 


2.00 


445 


.09 


.23 


50 


.45 


1.13 


2.50 


.81 


2.03 


451 


.10 


.25 


56 


.46 


1.15 


256 


.82 


2.05 


458 


.11 


.28 


61 


.47 


1.18 


261 


.83 


2.08 


462 


.12 


.30 


67 


.48 


1.20 


265 


.84 


2.10 


467 


.13 


.33 


72 


.49 


1.23 


273 


.85 


2.13 


473 


.14 


.35 


78 


.50 


1.25 


278 


.86 


2.15 


478 


.15 


.38 


83 


.51 


1.28 


284 


.87 


2.18 


484 


.16 


.40 


89 


.52 


1.30 


289 


.88 


2.20 


489 


.17 


.43 


95 


.53 


1..33 


295 


.89 


2.23 


495 


.18 


.45 


100 


.54 


1.35 


300 


.90 


2.25 


501 


.19 


.48 


106 


.55 


1.38 


306 


.91 


2.28 


506 


.20 


.50 


111 


.56 


1.40 


311 


.92 


2.30 


512 


.21 


.53 


117 


.57 


1.43 


317 


.93 


2.33 


515 


.22 


.55 


122 


.58 


1.45 


323 


.94 


2.35 


523 


.23 


.58 


128 


.59 


1.48 


328 


.95 


2.38 


528 


.24 


.60 


133 


.60 


1.50 


334 


.96 


2.40 


534 


.25 


.63 


139 


.61 


1.53 


339 


.97 


2.43 


539 


.26 


.65 


145 


.62 


i;55 


345 


.98 


2.45 


545 


.27 


.68 


150 


.63 


1.58 


350 


.99 


2.48 


551 


.28 


.70 


156 


.64 


1.60 


356 


1.00 


2.50 


556 


.29 


.73 


161 


.65 


1.63 


362 


1.01 


2.53 


562 


.30 


.75 


167 


.66 


1.65 


367 


1.02 


3.55 


567 


.31 


.78 


173 


.67 


1.68 


373 


1.03 


2.58 


573 


.32 


.80 


178 


.68 


1.70 


378 


1.04 


2.60 


578 


.33 


.83 


184 


.69 


1.73 


384 


1.05 


2.63 


584 


.34 


.85 


189 


.70 


1.75 


389 


1.06 


2.65 


590 


.35 


.88 


195 


.71 


1.78 


395 


1.07 


2.68 


595 



242 Standardizing Sweetened Condensed Milk 

TABLE 42 (Continued). 



Pe- Cent 
Fat 


Per Cent 
Milk 

S. N.F. 


Lbs. Sugar to 
use for cor- 
responding 
wt. of Fat. 


Per Cent 
Fat 


Per Cent 
Milk 

S. N. F. 


Lbs. Sugar to 
use for cor- 
responding 
wt. of Fat. 


Per Cent 
Fat 


Per Cent 
Milk 

S. N.F. 


Lbs. Sugar to 
us 3 for cor- 
responding 
wt. of Fat. 


1.08 


2.70 


601 


1.51 


3.78 


840 


1.94 


4.85 


1079 


1.09 


2.73 


605 


1.52 


3.80 


845 


1.95 


4.88 


1085 


1.10 


2.75 


612 


1.53 


3.83 


851 


1.96 


4.90 


1090 


1.11 


2.78 


617 


1.54 


3.85 


857 


1.97 


4.93 


1096 


1.12 


2.80 


623 


1.55 


3.88 


862 


1.98 


4.95 


1101 


1.13 


2.83 


628 


1.56 


3.90 


868 


1.99 


4.98 


1107 


1.14 


2.85 


634 


1.57 


3.93 


873 


2.00 


5.00 


1112 


1.15 


2.88 


640 


1.58 


3.95 


879 


2.01 


5.03 


1118 


1.16 


2.90 


645 


1.59 


3.98 


884 


2.02 


5.05 


1123 


1.17 


2.93 


651 


1.60 


4.00 


890 


2.03 


5.08 


1129 


1.18 


2.95 


658 


1.61 


4.03 


895 


2.04 


5.10 


1135 


1.19 


2.98 


662 


1.62 


4.06 


901 


2.05 


5.13 


1140 


1.20 


3.00 


667 


1.63 


4.08 


907 


2.06 


5.15 


1146 


1.21 


3.03 


673 


1.64 


4.10 


912 


2.07 


5.18 


1151 


1.22 


3.05 


679 


1.65 


4.13 


918 


2.08 


5.20 


1157 


1.23 


3.08 


684 


1.66 


4.15 


923 


2.09 


5.23 


1162 


1.24 


3.10 


690 


1.67 


4.18 


929 


2.10 


5.25 


1168 


1.25 


3.13 


695 


1.68 


4.20 


934 


2.11 


5.28 


1174 


1.26 


3.15 


701 


1.69 


4.23 


940 


2.12 


6.30 


1179 


1.27 


3.18 


706 


1.70 


4.25 


945 


2.13 


5.33 


1185 


1.28 


3.20 


712 


1.71 


4.28 


951 


2.14 


5.35 


1190 


1.29 


3.23 


717 


1.72 


4.30 


957 


2.15 


5.38 


1196 


1.30 


3.25 


723 


1.73 


4.33 


962 


2.16 


5.40 


1201 


1.31 


3.28 


729 


1.74 


4.35 


968 


2.17 


5.43 


1207 


1.32 


3.30 


734 


1.75 


4.38 


973 


2.18 


5.45 


1212 


1.33 


3.33 


740 


1.76 


4.40 


979 


2.19 


5.48 


1218 


1.34 


3.36 


745 


1.77 


4.43 


984 


2.20 


5.50 


1224 


1.35 


3.38 


751 


1.78 


4.45 


990 


2.21 


5.53 


1229 


1.36 


3.40 


756 


1.79 


4.48 


996 


2.22 


5.55 


1233 


1.37 


3.43 


762 


1.80 


4.50 


1001 


2.23 


5.58 


1240 


1.38 


3.45 


768 


1.81 


4.53 


1007 


2.24 


5.60 


1246 


1.39 


3.48 


773 


1.82 


4.55 


1012 


2.25 


5.63 


1351 


1.40 


3.50 


779 


1.83 


4.58 


1018 


2.26 


5.65 


1257 


1.41 


3.53 


784 


1.84 


4.60 


1023 


2.27 


5.68 


1263 


1.42 


3.55 


790 


1.85 


4.63 


1028 


2.28 


5.70 


1268 


1.43 


3.58 


795 


1.86 


4.65 


1034 


2.29 


5.73 


1274 


1.44 


3.60 


801 


1.87 


4.68 


1040 


2.30 


5.75 


1279 


1.45 


3.63 


806 


1.88 


4.70 


1046 


2.31 


5.78 


1285 


1.46 


3.65 


812 


1.89 


4.73 


1051 


2.32 


5.80 


1290 


1.47 


3.68 


818 


1.90 


4.75 


1057 


2.33 


5.83 


1293 


1.48 


3.70 


823 


1.91 


4.78 


1062 


2.34 


5.85 


1301 


1.49 


3.73 


829 


1.92 


4.80 


1068 


2.35 


5.88 


1307 


1.50 


3.75 


834 


1.93 


4.83 


1073 


2.36 


5.90 


1313 



Standardizing Tables 
TABLE 42 (Continued). 



243 



Per Cent 
Fat 


Per Cent 
Milk 

S. N.F. 


Lbs. Sugar to 
use for cor- 
responding 
wt. of Fat 


Per Cent 
Fat 


Per Cent 
Milk 

S. N. F. 


Lbs. Sugar to 
use for cor- 
responding 
wt. of Fat 


Per Cen 
Fat 


Per Cent 
Milk 

S. N. F 


Lb.s. Sugar to 
use for cor- 
responding 
wt. of Fat. 


2.37 


5.93 


1318 


2.80 


7.00 


1557 


3.23 


8.08 


1796 


2.38 


5.96 


1324 


2.81 


7.03 


1563 


3.24 


8.10 


1802 


2.39 


5.98 


1329 


2.82 


7.05 


1568 


3.25 


8.13 


1808 


2.40 


6.00 


1335 


2.83 


7.08 


1574 


3.26 


8.15 


1813 


2.41 


6.03 


1340 


2.84 


7.10 


1580 


3.27 


8.18 


1819 


2.42 


6.05 


1346 


2.85 


7.13 


1585 


3.28 


8.20 


1824 


2.43 


6.08 


1352 


2.86 


7.15 


1591 


3.29 


8.23 


1830 


2.44 


6.10 


1357 


2.87 


7.18 


1596 


3.30 


8.25 


1835 


2.45 


6.13 


1363 


2.88 


7.20 


1602 


3.31 


8.28 


1841 


2.46 


6.15 


1368 


2.89 


7.23 


1607 


3.32 


8.30 


1846 


2.47 


6.18 


1374 


2.90 


7.25 


1613 


3.33 


8.33 


1852 


2.48 


6.20 


1379 


2.91 


7.28 


1618 


3.34 


8.35 


1858 


2.49 


6.23 


1385 


2.92 


7.30 


1624 


3.35 


8.38 


1863 


2.50 


6.25 


1390 


2.93 


7.33 


1630 


3.36 


8.40 


1869 


2.51 


6.28 


1398 


2.94 


7.35 


1635 


3.37 


8.43 


1874 


2.52 


6.30 


1401 


2.95 


7.39 


1641 


3.38 


8.45 


1880 


2.53 


6.33 


1407 


2.96 


7.40 


1646 


3.39 


8.48 


1885 


2.54 


6.35 


1413 


2.97 


7.43 


1651 


3.40 


8.50 


1891 


2.55 


6.38 


1418 


2.98 


7.45 


1657 


3.41 


8.53 


1897 


2.56 


6.40 


1424 


2.99 


7.48 


1663 


3.42 


8.55 


1902 


2.57 


6.43 


1429 


3.00 


7.50 


1669 


3.43 


8.58 


1908 


2.58 


6.45 


1436 


3.01 


7.53 


1674 


3.44 


8.60 


1913 


2.59 


6.48 


1440 


3.02 


7.55 


1680 


3.45 


8.63 


1919 


2.60 


6.50 


1446 


3.03 


7.58 


1685 


3.46 


8.65 


1924 


2.61 


6.53 


1452 


3.04 


7.60 


1691 


3.47 


8.68 


1930 


2.62 


6.56 


1457 


3.05 


7.63 


1696 


3.48 


8.70 


1935 


2.63 


6.58 


1462 


3.06 


7.65 


1702 


3.49 


8.73 


1941 


2.64 


6.60 


1468 


3.07 


7.68 


1707 


3.50 


8.75 


1947 


2.65 


6.63 


1474 


3.08 


7.70 


1713 


3.51 


8.78 


1952 


2.66 


6.65 


1479 


3.09 


7.73 


1719 


3.52 


8.80 


1958 


2.67 


6.68 


1485 


3.10 


7.75 


1724 


3.53 


8.83 


1963 


2.68 


6.70 


1491 


3.11 


7.78 


1730 


3.54 


8.85 


1969 


2.69 


6.73 


1496 


3.12 


7.80 


1735 


3.55 


8.88 


1974 


2.70 


6.76 


1502 


3.13 


7.83 


1741 


3.56 


8.90 


1980 


2.71 


6.78 


1507 


3.14 


7.85 


1746 


3.57 


8.93 


1986 


2.72 


6.80 


1513 


3.15 


7.88 


1752 


3.58 


8.95 


1991 


2.73 


6.83 


1518 


3.16 


7.90 


1758 


3.59 


8.98 


1997 


2.74 


6.85 


1524 


3.17 


7.93 


1763 


3.60 


9.00 


2002 


2.75 


6.88 


1529 


3.18 


7.95 


1769 


3.61 


9.03 


2008 


2.76 


6.90 


1539 


3.19 


7.98 


1774 


3.62 


9.05 


2013 


2.77 


6.93 


1541 


3.20 


8.00 


1780 


3.63 


9.08 


2019 


2.78 


6.96 


1546 


3.21 


8.03 


1785 


3.64 


9.10 


2124 


2.79 


6.98 


1552 


3.22 


8.05 


1791 


3.65 


9.13 


2030 



244 v^TANDARDIZING SwEETENED CoNDENSED MiLK 

TABLE 42 (Continued). 



Per Cent 
Fat 


Per Cent 
Milk 

S. N. F. 


Lbs. Sugar to 
use for cor- 
responding 
wt. of Fat 


Per Cent 
Fat 


Per Cent 
Milk 

S. N. F. 


Lbs. Sugar to 
use for cor- 
responding 
wt. of Fat 


Per Cent 
Fat 


Per Cent 
Milk 

S. N. F. 


Lbs. Sugar to 
use for cor- 
responding 
wt. of Fat 


3.66 


9.15 


2036 


4.09 


10.23 


2275 


4.52 


11.30 


2514 


3.67 


9.18 


2041 


4.10 


10.25 


2280 


4.53 


11.33 


2519 


3.68 


9.20 


2047 


4.11 


10.28 


2286 


4.54 


11.35 


2525 


3.69 


9.23 


2053 


4.12 


10.30 


2291 


4.55 


11.38 


2531 


3.70 


9.25 


2058 


4.13 


10.33 


2297 


4.56 


11.40 


2536 


3.71 


9.28 


2064 


4.14 


10.35 


2303 


4.57 


11.43 


2542 


3.72 


•9.30 


2069 


4.15 


10.38 


2308 


4.58 


11.45 


2547 


3.73 


9.33 


2075 


4.16 


10.40 


2314 


4.59 


11.48 


2553 


3.74 


9.35 


2080 


4.17 


10.43 


2319 


4.60 


11.50 


2558 


3.75 


9.38 


2086 


4.18 


10.45 


2325 


4.61 


11.53 


2564 


3.76 


9.40 


2091 


4.19 


10.48 


2330 


4.62 


11.55 


2570 


3.77 


9.43 


2097 


4.20 


10.50 


2336 


4.63 


11.58 


2575 


3.78 


9.45 


2102 


4.21 


10.53 


2341 


4.64 


11.60 


2581 


3.79 


9.48 


2108 


4.22 


10.55 


2347 


4.65 


11.63 


2586 


3.80 


9.50 


2113 


4.23 


10.58 


2353 


4.66 


11.65 


2592 


3.81 


9.53 


2119 


4.24 


10.60 


2358 


4.67 


11.68 


2597 


3.82 


9.55 


2125 


4.25 


10.63 


2364 


4.68 


11.70 


2603 


3.83 


9.58 


2130 


4.26 


10.65 


2369 


4.69 


11.73 


2608 


3.84 


9.60 


2136 


4.27 


10.68 


2375 


4.70 


11.75 


2614 


3.85 


9.63 


2141 


4.28 


10.70 


2380 


4.71 


11.78 


2620 


3.86 


9.65 


2147 


4.29 


10.73 


2386 


4.72 


11.80 


2625 


3.87 


9.68 


2152 


4.30 


10.75 


2392 


4.73 


11.83 


2631 


3.88 


9.70 


2158 


4.31 


10.78 


2397 


4.74 


11.85 


2636 


3.89 


9.73 


2164 


4.32 


10.80 


2403 


4.75 


11.88 


2642 


3.90 


9.75 


2169 


4.33 


10.83 


2408 


4.76 


11.90 


2647 


3.91 


9.78 


2175 


4.34 


10.85 


2414 


4.77 


11.93 


2653 


3.92 


9.80 


2180 


4.35 


10.88 


2419 


4.78 


11.95 


2659 


3.93 


9.83 


2186 


4.36 


10.90 


2425 


4.79 


11.98 


2664 


3.94 


9.85 


2191 


4.37 


10.93 


2430 


4.80 


12.00 


2670 


3.95 


9.88 


2197 


4.38 


10.95 


2436 


4.81 


12.03 


2675 


3.96 


9.90 


2202 


4.39 


10.98 


2442 


4.82 


12.05 


2681 


3.97 


9.93 


2208 


4.40 


11.00 


2447 


4.83 


12.08 


2686 


3.98 


9.95 


2214 


4.41 


11.03 


2453 


4.84 


12.10 


2692 


3.99 


9.98 


2219 


4.42 


11.05 


2458 


4.85 


12.13 


2697 


4.00 


10.00 


2225 


4.43 


11.08 


2464 


4.86 


12.15 


2703 


4.01 


10.03 


2230 


4.44 


11.10 


2469 


4.87 


12.18 


2709 


4.02 


10.05 


2236 


4.45 


11.13 


2475 


4.88 


12.20 


2714 


4.03 


10.08 


2241 


4.46 


11.15 


2481 


4.89 


12.23 


2720 


4.04 


10.10 


2247 


4.47 


11.18 


2486 


4.90 


12.25 


2725 


4.05 


10.13 


2253 


4.48 


11.20 


2492 


4.91 


12.28 


2731 


4.06 


10.15 


2258 


4.49 


11.23 


2497 


4.92 


12.30 


2736 


4.07 


10.18 


2264 


4.50 


11.25 


2503 


4.93 


12.33 


2742 


4.08 


10.20 


2269 


4.51 


11.28 


2508 


4.94 


12.35 


2747 



Standardizing Tabi,e;s 



245 



TABLE 42 (Continued). 



Per Cent 
Fat 


Per Cent 
Milk 

S. N. F. 


Lbs. Sugar to 
use for cor 
responding 
wt. of Fat 


Per Cent 
Fat 


Per Cent 
Milk 

S. N. F. 


Lbs. Sugar to 
use for cor- 
responding 
wt. of Fat 


Per Cent 
Fat 


Per Cent 
Milk 

S. N. F. 


Lbs. Sugar to 
use for cor- 
responding 
wt. of Fat 


4.95 


12.38 


2753 


5.38 


13.45 


2992 


5.81 


14.53 


3231 


4.96 


12.40 


2759 


5.39 


13.48 


2998 


5.82 


14.55 


3237 


4.97 


12.43 


2764 


5.40 


13.50 


3003 


5.83 


14.58 


3242 


4.98 


12.45 


2770 


5.41 


13.53 


3008 


5.84 


14.60 


3248 


4.99 


12.48 


2775 


5.42 


13.55 


3014 


5.85 


14.63 


3254 


5.00 


12.50 


2781 


5.43 


13.58 


3020 


5.86 


14.65 


3259 


5.01 


12.53 


2786 


5.44 


13.60 


3026 


5.87 


14.68 


3265 


5.02 


12.55 


2793 


5.45 


13 . 63 


3031 


5.88 


14.70 


3270 


5.03 


12.58 


2798 


6.46 


13.65 


3037 


5.89 


14.73 


3276 


5.04 


12.60 


2803 


5.47 


13.68 


3042 


5.90 


14.75 


3281 


5.05 


12.63 


2809 


5.48 


13.70 


3048 


5.91 


14.78 


3287 


5.06 


12.65 


2814 


5.49 


13.73 


3053 


5.92 


14.80 


3293 


5.07 


12.68 


2820 


5.50 


13.75 


3059 


5.93 


14.83 


3298 


5.08 


12.70 


2825 


5.51 


13.78 


3065 


5.94 


14.85 


3304 


5.09 


12.73 


2831 


5.52 


13.80 


3070 


5.95 


14.88 


3309 


5.10 


12.75 


2836 


5.53 


13.83 


3076 


5.96 


14.90 


3315 


5.11 


12.78 


2842 


5.54 


13.85 


3081 


5.97 


14.93 


3320 


5.12 


12.80 


2848 


5.55 


13.88 


3087 


5.98 


14.95 


3326 


5.13 


12.83 


2853 


5.56 


13.90 


3092 


5.99 


14.98 


3331 


5.14 


12.85 


2859 


5.57 


13.93 


3098 


6.00 


15.00 


3337 


5.15 


12.88 


2864 


5.58 


13.95 


3103 


6.01 


15.03 


3343 


5.16 


12.90 


2870 


5.59 


13.98 


3109 


6.02 


15.05 


3348 


5.17 


12.93 


2875 


5.60 


14.00 


3315 


6.03 


15.08 


3354 


5.18 


12.95 


2881 


5.61 


14.03 


3120 


6.04 


15.10 


3359 


5.19 


12.98 


2887 


5.62 


14.05 


3126 


6.05 


15.13 


3365 


5.20 


13.00 


2892 


5.63 


14.08 


3131 


6,06 


15.15 


3370 


5.21 


13.03 


2898 


5.64 


14.10 


3137 


6.07 


15.18 


3376 


5.22 


13.05 


2903 


5.65 


14.13 


3142 


6.08 


15.20 


3382 


5.23 


13.08 


2909 


5.66 


14. 15' 


3148 


6.09 


15.23 


3387 


5.24 


13.10 


2914 


5.67 


14.18 


3154 


6.10 


15.25 


3393 


5.25 


13.13 


2920 


5.68 


14.20 


3159 


6.11 


15.28 


3398 


5.26 


13.15 


2925 


5.69 


14.23 


3165 


6.12 


15.30 


3404 


5.27 


13.18 


2931 


5.70 


14.25 


3170 


6.13 


15.33 


3409 


5.28 


13.20 


2937 


5.71 


14.28 


3176 


6.14 


15.35 


3415 


5,29 


13.23 


2942 


5.72 


14.30 


3181 


6.15 


15.38 


3420 


5.30 


13.25 


2948 


5.73 


14.33 


3187 


6.16 


15.40 


3426 


5.31 


13.28 


2953 


5.74 


14.35 


3192 


6.17 


15.43 


3432 


5.32 


13.30 


2959 


5.75 


14.38 


3198 


6.18 


15.45 


3437 


5.33 


13.33 


2964 


5.76 


14.40 


3204 


6.19 


15.48 


3443 


5.34 


13.35 


2970 


5.77 


14.43 


,3209 


6.20 


15.50 


3448 


5.35 


13.38 


2976 


5.78 


14.45 


3215 


6.21 


15.53 


3454 


5.36 


13.40 


2981 


5.79 


14.48 


3220 


6.22 


15.55 


3459 


5.37 


13.43 


2987 


5.80 


14.50 


3226 


6.23 


15.58 


3465 



246 



Standardizing SwEETKned Condensed Mii^k 



TABLE 42 (Continued). 



Per Cent 
Fat 


Per Cent 

Milk 
S. N. F. 


jbs. Sugar to 
use for cor- 
responding 
wt. of Fat. 


Per Cent 
Fat 


Per Cent 
Milk 

S. N. F. 


Lbs. Sugar to 
use for cor- 
responding 
wt. of Fat. 


Per Cent 

Fat 


Per Cent 
Milk 

S. N. F. 


Lbs. Sugar to 
use for cor- 
responding 
wt. of Fat. 


6.24 


15.60 


3471 


6.67 


16.68 


3710 


7.10 


17.75 


3949 


6.25 


15.63 


3476 


6.68 


16.70 


3715 


7.11 


17.78 


3954 


6.26 


15.65 


3482 


6.69 


16.73 


3721 


7.12 


17.80 


3960 


6.27 


15.68 


3487 


6.70 


16.75 


3726 


7.13 


17.83 


3966 


6.28 


15.70 


3493 


6.71 


16.78 


3732 


7.14 


17.85 


3971 


6.29 


15.73 


3498 


6.72 


16.80 


3737 


7.15 


17.88 


3977 


6.30 


15.75 


3504 


6.73 


16.83 


3743 


7.16 


17.90 


3982 


6.31 


15.78 


3509 


6.74 


16.85 


3749 


7.17 


17.93 


3988 


6.32 


15.80 


3515 


6.75 


16.88 


3754 


7.18 


17.95 


3993 


6.33 


15.83 


3521 


6.76 


16.90 


3760 


7.19 


17.98 


3999 


6.34 


15.85 


3528 


6.77 


16.93 


3765 


7.20 


18.00 


4004 


6.35 


15.88 


3532 


6.78 


16.95 


3771 


7.21 


18.03 


4010 


6.36 


15.90 


3543 


6.79 


16.98 


3776 


7.22 


18.05 


4016 


6.37 


15.93 


3545 


6.80 


17.00 


3782 


7.23 


18.08 


4021 


6.38 


15.95 


3548 


6.81 


17.03 


3788 


7.24 


18.10 


4027 


6.39 


15.98 


3554 


6.82 


17.05 


3793 


7.25 


18.13 


4032 


6.40 


16.00 


3560 


6.83 


17.08 


3799 


7.26 


18.15 


4038 


6.41 


16.03 


3565 


6.84 


17.10 


3804 


7.27 


18.18 


4043 


6.42 


16.05 


3571 


6.85 


17.13 


3810 


7.28 


18.20 


4049 


6.43 


16.08 


3576 


6.86 


17.15 


3815 


7.29 


18.23 


4055 


6.44 


16.10 


3582 


6.87 


17.18 


3821 


7.30 


18.25 


4060 


6.45 


16.13 


3587 


6.88 


17.20 


3826 


7.31 


18.28 


4066 


6.46 


16.15 


3593 


6.89 


17.23 


3832 


7.32 


18.30 


4071 


6.47 


16.18 


3598 


6.90 


17.25 


3838 


7.33 


18.33 


4077 


6.48 


16.20 


3604 


6.91 


17.28 


3843 


7.34 


18.35 


4082 


6.49 


16.23 


3610 


6.92 


17.30 


3849 


7.35 


18.38 


4088 


6.50 


16.25 


3615 


6.93 


17.33 


3854 


7.36 


18.40 


4093 


6.51 


16.28 


3621 


6.94 


17.35 


3860 


7.37 


18.43 


4099 


6.52 


16.30 


3626 


6.95 


17.38 


3865 


7.38 


18.45 


4105 


6.53 


16.33 


3632 


6.96 


17.40 


3871 


7.39 


18.48 


4110 


6.54 


16.35 


3637 


6.97 


17.43 


3877 


7.40 


18.50 


4116 


6.55 


16.38 


3643 


6.98 


17.45 


3883 


7.41 


18.53 


4121 


6.56 


16.40 


3648 


6.99 


17.48 


3888 


7.42 


18.55 


4127 


6.57 


16.43 


3654 


7.00 


17.50 


3893 


7.43 


18.58 


4132 


6.58 


16.45 


3660 


7.01 


17.53 


3899 


7.44 


18.60 


4138 


6.59 


16.48 


3665 


7.02 


17.55 


3904 


7.45 


18.63 


4143 


6.60 


16.50 


3671 


7.03 


17.58 


3910 


7.46 


18.65 


4148 


6.61 


16.53 


3676 


7.04 


17.60 


3915 


7.47 


18.68 


4155 


6.62 


16.55 


3682 


7.05 


17.03 


3921 


7.48 


18.70 


4160 


6.63 


16.58 


3687 


7.06 


17.65 


3927 


7.49 


18.73 


4166 


6.64 


16.60 


3693 


7.07 


17.68 


3932 


7.50 


18.75 


4171 


6.65 


16.63 


3699 


7.08 


17.70 


3938 


7.51 


18.78 


4177 


6.66 


16.65 


3704 


7.09 


17.73 


3943 


7.52 


18.80 


4182 



Standardizing Tables 



247 



TABLE 42 (Continued). 



Per Cent 
Fat 


Per Cent 
Milk 

S. N. F. 


Lbs. Sugar to 
use for cor- 
responding 
wt. of Fat 


Per Cent 
Fat 


Per Cent 

Milk 
S. N. F. 


Lbs. Sugar to 
use for cor- 
responding 
wt. of Fat 


Per Cent 
Fat 


Per Cent 
Milk 

S.N. F. 


Lbs. Sugar to 
use for cor- 
responding 
wt. of Fat 


7.53 


18.83 


4188 


7.96 


19.90 


4427 


8.39 


20.98 


4666 


7.54 


■18.85 


4194 


7.97 


19.93 


4433 


8.40 


21,00 


4672 


7.55 


18.87 


4199 


7.98 


19.95 


4438 


8.41 


21.03 


4677 


7.56 


18.90 


4205 


7.99 


19.98 


4444 


8.42 


21.05 


4683 


7.57 


18.93 


4210 


8.00 


20.00 


4449 


8.43 


21.08 


4689 


7.58 


18.95 


4216 


8.01 


20.03 


4455 


8.44 


21.10 


4695 


7.59 


18.97 


4221 


8.02 


20.05 


4460 


8.45 


21 . 13 


4700 


7.60 


19.00 


4227 


8.03 


20.08 


4466 


8.46 


21 . 15 


4705 


7.61 


19.03 


4232 


8.04 


20.10 


4472 


8.47 


21.18 


4711 


7.62 


19.05 


4238 


8.05 


20.13 


4477 


8.48 


21.20 


4716 


7.63 


19.08 


4244 


8.06 


20.15 


4483 


8.49 


21.23 


4722 


7.64 


19.10 


4249 


8.07 


20.18 


4488 


8.50 


21.25 


4727 


7.65 


19.13 


4255 


8.08 


20.20 


4494 


8.51 


21.28 


4733 


7.66 


19.15 


4260 


8.09 


20.23 


4499 


8.52 


21.30 


4739 


7.67 


19.18 


4266 


8.10 


20.25 


4505 


8.53 


21.33 


4744 


7.68 


19.20 


4271 


8.11 


20.28 


4511 


8.54 


21.35 


4750 


7.69 


19.23 


4277 


8.12 


20.30 


4516 


8.55 


21.38 


4756 


7.70 


19.25 


4283 


8.13 


20.33 


4522 


8.56 


21.40 


4761 


7.71 


19.28 


4288 


8.14 


20.35 


4527 


8.57 


21.43 


4766 


7.72 


19.30 


4294 


8.15 


20.38 


4533 


8.58 


21.45 


4772 


7.73 


19.33 


4299 


8.16 


20.40 


4538 


8.59 


21.48 


4778 


7.74 


19.35 


4303 


8.17 


20,43 


4544 


8.60 


21.50 


4783 


7.75 


19.37 


4310 


8.18 


20.45 


4549 


8.61 


21.53 


4789 


7.76 


19.40 


4^16 


8.19 


20.48 


4555 


8.62 


21.55 


4794 


7.77 


19.43 


4321 


8.20 


20.50 


4561 


8.63 


21.58 


4800 


7,78 


19.45 


4327 


8.21 


20.53 


4566 


8.64 


21.60 


4805 


7.79 


19.48 


4333 


8.22 


20.55 


4572 


8.65 


21 .63 


4811 


7.80 


19.50 


4338 


8.23 


20.58 


4577 


8.66 


21.65 


4816 


7.81 


19.53 


4344 


8.24 


20.60 


4583 


8.67 


21.68 


4822 


7.82 


19.55 


4349 


8.25 


20.63 


4588 


8.68 


21.70 


4828 


7.83 


19.58 


4355 


8.26 


20.65 


4594 


8.69 


21.73 


4833 


7.84 


19.60 


4360 


8.27 


20.68 


4600 


8.70 


21.75 


4839 


7.85 


19.63 


4366 


8.28 


20.70 


4605 


8.71 


21.78 


4844 


7.86 


19.65 


4371 


8.29 


20.73 


4611 


8.72 


21.80 


4850 


7.87 


19.68 


4377 


8.30 


20.75 


4616 


8.73 


21.83 


4855 


7.88 


19.70 


4383 


8.31 


20.78 


4622 


8.74 


21.85 


4861 


7.89 


19.73 


4388 


8.32 


20.80 


4627 


8.75 


21.88 


4867 


7.90 


19.75 


4394 


8.33 


20.83 


4633 


8.76 


21.90 


4872 


7.91 


19.78 


4399 


8.34 


20.85 


4638 


8.77 


21.93 


4878 


7.92 


19.80 


4405 


8.35 


20.88 


4644 


8.78 


21.95 


4883 


7.93 


19.83 


4410 


8.36 


20.90 


4650 


8.79 


21.98 


4889 


7.94 


19.85 


4416 


8.37 


20.93 


4655 


8.80 


22.00 


4894 


7.95 


19.88 


4422 


8.38 


20.95 


4661 


8.81 


22.03 


4900 



248 



Standardizing Sweetened Condensed Milk 



TABLE 42 (Continued). 



Per Cent 
Fat 


Per Cent 
Milk 

s. n. f. 


Lbs. Sugar to 
use for cor- 
responding 
wt. of Fat 

4905 


Per Cent 
Fat 


Per Cent 
Milk 

S. N. F. 


Lbs. Sugar to 
use for cor- 
responding 
wt. of Fat 


Per Cent 
Fat 


Per Cent 

Milk 
S. N.F. 


Lbs. Sugar to 
use for cor- 
responding 
wt. of I'at 


8.82 


22.05 


8.88 


22.20 


4939 


8.94 


22.35 


4972 


8.83 


22.08 


4911 


8.89 


22.23 


4944 


8.95 


22.38 


4978 


8.84 


22.10 


4917 


8.90 


22.25 


4950 


8.96 


22.40 


4983 


8.85 


22.13 


4922 


8.91 


22.28 


4956 


8.97 


22.43 


4989 


8.86 


22.15 


4928 


8.92 


22.30 


4961 


8.98 


22.45 


4994 


8.87 


22.18 


4933 


8.93 


22.33 


4967 


8.99 


22.48 


5000 



KEY TO FORMULAS FOR STANDARDIZING SWEETENED 
CONDENSED MILK. 

D = The pounds of condensed whole milk. 

P =r The percentage of fat in the whole milk. 

G = The percentage of fat in the cream. 

G^ = The percentage of fat in the unsweetened condensed skim- 
milk. 

I = The percentage of S. N. F. in the sweetened condensed skim- 
milk. 

I^ = The percentage of S. N. F. in the unsweetened condensed 
skim-milk. 

J = The percentage of S. N. F. in the cream. 

K = The percentage of fat in the skim-milk. 

K^ = The percentage of fat in the condensed whole milk. 

L ^ The pounds of skim-milk. 

L^ = The pounds of sweetened condensed skim-milk, 

M = The percentage of fat in the sweetened condensed skim- 
milk. 

N = The percentage of S. N. F. in the skim-milk. 

N^ = The percentage of T. S. in the skim-milk. 

O = The pounds of cream. 

P = The pounds of whole milk. 

Q = The pounds of condensed skim-milk. 

R =z The ratio of S. N. F. to fat in the desired product. 

S = The percentage of S. N. F. in the whole milk. 

S^ = The average percentage of fat in the mixed batch. 

§2 :^ The percentage of S. N. F. in the unsweetened condensed 
whole milk. 

S^ = The percentage of S. N. F. in the mixed batch. 



KcY TO Standardizing Tables 249 

U = The pounds of sugar required, 

V r= The percentage of S. N. F. in the cream, 

V^ = The percentage of S. N, F, in the mixed batch, 

Y = The ratio of sugar to fat, 

Y^ = The ratio of sugar to total solids, 

Y^ = The ratio of total milk solids to sugar, 

Z = The percentage of sugar in the sweetened condensed milk. 

PROVIDING FACTOR OF SAFETY. 

In all the problems given in this chapter, the calculations are 
made upon the basis of the absolute standard without allowing 
any factor of safety. It is recommended that in practice in the 
case of sweetened condensed milk, a factor of safety be allowed 
of about ,10 per cent upon the fat and ,30 per cent upon the T. S. 
It may be possible under the best conditions of plant operation 
to reduce this factor slightly, 

STANDARDIZING SWEETENED CONDENSED MILK REFORE 

CONDENSING. 
Problem 18 : How to Calculate the Pounds of Skim-milk to Add 

to Whole Milk. 

The ratio between the percentage of milk S, N, F, and the per- 
centage of fat in the whole milk must be more than the required 
ratio. 
Solution of Problem 18, based upon Rule 16: 

(1.) Divide the percentage of fat in the skim-milk by the 
ratio between the S. N, F, and the fat in the product desired. Sub- 
tract the answer from the S, N, F, in the skim-milk. Call the re- 
mainder A, or the percentage of S, N, F. available for standard- 
izing, 

(2,) Divide the percentage of fat in the whole milk by the 
ratio between the S, N. F, and the fat in the product desired. Call 
answer B. Subtract from B the percentage of S. N. F. present 
in the whole milk. Multiply the remainder by the pounds of 
whole milk in the batch. Call the result C. 

(3.) Divide C by A. The answer will be the pounds of skim- 
milk necessaiy to standardize the batch to the required ratio, 

(4,) Multiply the pounds of whole milk by the fat test of 
the whole milk. Call the product D. Multiply the pounds of 
skim-milk by the fat test of the skim-milk. Call the product E. 



250 



Standardizing Sweetened Condensed Mii,k 



Add D plus E and divide the sum by the ratio between the sugar 
and the fat, in the product desired. The answer will be the 
pounds of sugar required for the total batch. 

Solution of Problem 18, based upon Formula 16: 

(1.) To calculate the pounds of skim-milk required. 



_ m-^v 



N- 



K 
R 



(2.) 



To calculate the pounds of sugar to add. 

(PF) + (LK) 



U=- 



Y 



Problem 18, Example 19: 



PRODUCTS 


PER CENT 


Pounds 


Fat 


M.S.N. F. 


Sugar 


T. S. 


Milk 


10,000 


3.79 


8.31 




12 10 






Skim-milk 




.16 


8,47 




8.63 






Composition desired after 
condensing 




8.00 


20.00 


44.50 


72.50 











Solution of Problem 18, Example 19, based upon Rule 16: 

(1.) To calculate the available S. N. F. in the skim-milk. 
.16 f-.40=:.40, per cent of milk S. N. F. required to equalize 
the fat in the skim-milk. 
8.47— .40=8.07, per cent of milk S. N. F. available for stand- 
ardizing. 

(2.) To calculate the pounds of S. N. F. short. 

3.79-f .40=9.48, per cent of S. N. F. required. 
9.48—8.31=1.17, per cent of S. N. F. short. 
lOOOOX. 0117=117, pounds of S. N. F. short. 

(3.) To calculate the pounds of skim-milk required. 

117-f-.0807=:144.'j,, pounds of skim-milk required. 

(4.) To calculate the pounds of sugar required. 
lOOOOX. 0379=379, pounds of fat in the whole milk. 



Problems in Standardizing 



251 



1443 X -0016= 2, pounds of fat in the skim-milk. 
379+ 2r= 381, or total pounds of fat in the entire batch. 
381-=-.1798=2120, pounds of sugar required for total batch. 
Condense sufficiently high to provide the proper factor of 
safety. 

Solution of Problem 18, Example 19, based upon Formula 16 : 
(1.) To calculate the pounds of skim-milk required. 



L = 



(•^_.083l)xl0000 



.0847- 



. 0016 
.40 



= 1443 



(2.) 



To calculate the pounds of sugar required. 

(10000X.0379) + (1443X.0016) _ 

^^ .1798 ~ 



2120 



Proof Problem 18, Example 19 


















POUNDS 


PER CENT 


Products 




Fat 


M.S. 

N.F. 


Sugar 


T.S. 


Fat 


M.S. 
N.F. 


Sugar 


T.S. 


Milk 


10000 


379 


831 




1210 


3.79 


8.31 




12.10 






Skim-milk 


1443 


2.3 


122 




124.3 


.16 


8.47 




8.73 


Sugar 


2120 






2120 


2120 






100 


100 






Standardized 
product 


13563 


381.3 


953 


2120 


3454.3 


2.76 


7.02 


15.64 


25.60 



























Ratio of M. S. N. F. to fat obtained is 381.3 ~ 953 = .40. 

STANDARDIZING SWEETENED CONDENSED MILK BEFORE 

CONDENSING. 

Problem 19: How to Calculate the Pounds of Cream to Add to 

Whole Milk. 

The ratio between the percentage of milk S. N. F. and fat in 
the whole milk must be less than the required ratio. 

Solution of Problem 19, based upon Rule 17 : 

(1.) Multiply the percentage of S. N. F. in the cream by the 
ratio between the S. N. F. and the fat in the product desired. 



252 



Standardizing Sweetened Condensed Milk 



Subtract the result from the percentage of fat in the cream. Call 
the remainder A, or the per cent of fat in the cream available 
for standardizing. 

(2.) Multiply the percentage of S. N. F. in the whole milk 
by the ratio between the S. N, F. and the fat in the product de- 
sired. Call the result B, or the percentage of fat required. Sub- 
tract from B the percentage of fat present in the whole milk. 
Multiply the remainder by the pounds of whole milk in the batch. 
Call the result C, or the pounds of fat short. 

(3.) Divide C by A. The answer will be the pounds of cream 
required to standardize the batch to the desired ratio. 

(4.) Multiply the pounds of whole milk by the fat test of 
the whole milk. Call the answer D. Multiply the pounds of 
cream by the fat test of the cream. Call the result E. Add D 
to E, and divide the sum by the ratio between the percentage 
of sugar and the percentage of fat in the product desired. The 
answer will be the number of pounds of sugar required for the 
total batch. 

Solution of Problem 19, based upon Formula 17: 
(1.) To calculate the pounds of cream required. 







[ (SR)_F] P 



G — VR 
(2.) To calculate the pounds of sugar required. 

_ (PF) + (OG) 
Y 

Problem 19, Example 20: 





Pounds 


PER CENT 




Fat 


M. S. N. F. 


Sugar 


T. S. 


Milk 


10000 


3.35 


8.63 




11.98 


Cream 




26.38 


6.44 




32.82 


Sugar 










100.00 


Composition 
after condens 


desired 

ins 


8.00 


20.00 


44.50 


72 50 







Problems in Standardizing 253 

Solution of Problem 19, Example 20, based upon Rule 17 : 

(1.) To calculate the available fat in the cream. 

6.44 X -40 = 2.56, per cent of fat required to equalize the 

S. N. F. in the cream. 
26.38 — 2.56 = 23.80, per cent of fat available for standardiz- 
ing. 

(2.) To calculate the pounds of fat short. 
8.63 X -40 = 3.45, per cent of fat required. 

3.45 — 3.35 = .10, per cent of fat short. 
10000 X .0010= 10 pounds, of fat short. 

(3.) To calculate the pounds of cream required. 

10 ~ .2380 = 43, pounds of cream required, 

(4.) To calculate the pounds of sug-ar required. 
10000 X .0335 = 335, pounds of fat in whole milk. 
43 X .2638 = 11, pounds of fat in cream, 
335 -(- 11 == 346, total pounds of fat in entire batch. 
346 -i- .1796 = 1926, pounds of sugar required for the total 
batch. 

Condense sufificiently to provide the proper factor of safety. 

Solution of Problem 19, Example 20, baised upon Formula 17 : 
(1,) To calculate the pounds of cream required. 

[(.0863 X. 40)— .03-351 X 10000 
~ .2638 — (.0644 X .40) ~ * 

(2.) To calculate the pounds of sugar required. 

(10000X.0335) + (42.85X.2638) ,^„^ 
.1798 



254 Standardizing Sweetened Condensed Milk 

Proof of Problem 19, Example 20: 







POUNDS 


PER CENT 


Products 


Fat 


M.S. 

n. f. 


Sugar 


T. S. 


Fat 


M. S. 

n. f. 


Sugar 


T. S. 


Milk .... 


10000 


335.00 


863 




1198 


3.35 


8.63 




11.98 


Cream. . . 


42.85 


11.39 


2.76 




14.06 


26.38 


6.44 




32.82 


Sugar. . . . 


1926.00 






1926 


1926.00 






100 


100.00 


Stand'zed 
Product 


11968.85 


346.30 


865.76 


1926 


3138.06 


2.83 


7.23 


16.09 


26.15 



Ratio of M. S. N. F. to fat obtained is 346.3 -^ 865.7 = .40. 
Ratio of sugar to fat obtained is 346.3 -^ 1926 = .1798. 

STANDARDIZING SWEETENED CONDENSED MILK BEFORE 

CONDENSING. 

Problem 20: How to Calculate the Pounds of Cream to Add to 

Skim-milk. 

Solution of Problem 20, based upon Rule 18 : 

(1.) Multiply the percentage of S. N. F. in the cream by the 
ratio between the S. N. F. and the fat in the product desired. 
Subtract the result from the percentage of fat in the cream. Call 
the remainder A, or the percentage of fat in the cream available 
for standardizing. 

(2.) Multiply the percentage of S. N.F. in the skim-milk by 
the ratio between the S. N. F. and the fat in the product desired. 
Call the result B. Subtract from B the percentage of fat in the 
skim-milk and multiply the remainder by the pounds of skim- 
milk in the batch. Call the result C. Divide C by A. The answer 
will be the pounds of cream required to standardize the batch to 
the required ratio. 

(3.) Multiply the pounds of skim-milk in the batch by the 
percentage of fat in the skim-milk. Call the answer D. Multiply 
the pounds of cream required by the percentage of fat in the 
cream. Call answer E. Add D to E and divide the sum of the 
two by the ratio between the percentage of cane sugar and the 
percentage of fat in the product desired. The answer will be the 
pounds of sugar required for the total batch. 



Problems in Standardizing 



255 



Solution of Problem 20, based upon Formula 18: 
(1.) To calculate the pounds of cream required. 

(NR)— K] L 



0=: 



G— (JR^ 



(2.) To calculate the pounds of sugar required. 

(LK) + (OG) 



U = 
Problem 20, Example 21: 



Y 





Pounds 


PER CENT 


Products 


Fat 


M. S. N. F. 


Sugar 


T. S. 


Skim-milk. . . 


10000 


.20 


8.63 




8.83 


Cream 




26.38 


6.44 




32.82 


Sugar 








100.00 


100.00 


Composition 
condensing. . 


desired after 


8.00 


20.00 


44.50 


72.50 







Solution of Problem 20, Example 21, based upon Rule 18: 

(1.) To calculate the available fat in the cream. 
6.44 X .40 = 2.58, per cent of fat required to equalize the 
S. N. F. in cream. 
26.38 — 2.58 == 23.80, per cent of fat in the cream available for 
standardizing. 
(2.) To calculate the pounds of fat short. 
8.63 X .40 = 3.45, per cent of fat required. 
3.45 — .20 = 3.25, per cent of fat short. 
10000 X .0325= 325, pounds of fat short. 

(3.) To calculate the pounds of cream required. 
325 :- .2380 =: 1366, pounds of cream required. 

(4.) To calculate the pounds of sugar required. 
10000 X .0020 = 20, pounds of fat in skim-milk. 
1366 X .2638 =: 360, pounds of fat in cream. 

20 + 360 = 380, total pounds of fat in the batch. 
380 -^ .1798 = 2115, pounds of sugar required for the total 
batch. 



256 Stand.ardizing Sweetened Condensed Milk 

Solution of Problem 20, Example 21, based upon Formula 18: 
(1.) To calculate the pounds of cream required. 

^^ [(.0863x.40)-.002] X 10000 ._ ^^^^ 
.2638— (.0644 X -40) 

(2.) To calculate the pounds of sugar required. 

^_ (10000 X .002) -f (1366 X .2638) _ 
~ .1798 ■ ~ " 

Proof of Problem 20, Example 21 : 









POUNDS 




PER CENT 


Products 


Fat 


M. S. 
N. F. 


Sugar 


T. S. 


Fat 


M.S. 

N. F. 


Sugar 


T. S. 


Skim- 
milk 


10000 


20 


863 




883 


.20 


8.63 




8.83 


Cream. . . 


1366 


360 


88 




448 


26.38 


6.44 




32.82 


Sugar. . . . 


2115 






2115 


2115 






100.00 


100.00 


Stand- 
ardized 
product 


13481 


380 


951 


2115 


3446 


2.82 


7.05 


15.52 


25.38 



Ratio of M. S. N. F. to fat obtained is 380 ~ 950 = .40. 
Ratio of sugar to fat obtained is 380^2115=.1798. 

STANDARDIZING SWEETENED CONDENSED MILK BEFORE 

CONDENSING. 

Problem 21: How to Calculate the Pounds of Cream to Add, 

Knowing the Pounds of Whole and Skim-milk on Hand, 

and the Percentage of Fat and S. N. F. in All 

Three Products. 

Solution of Problem 21, based upon Rule 19 : 

(1.) If the ratio between the S. N. F. and the fat in the fresh 
milk is more than the required ratio, standardize the fresh milk 
with the skim-milk, using Rule 16. Deduct the pounds of skim- 



Probi<ems in Standardizing 257 

milk required to standardize the fresh milk from the total pounds 
of skim-milk on hand. 

(2.) If the ratio between the percentage of S. N. F. and the 
percentage of fat in the fresh milk is less than the required ratio, 
standardize the fresh milk with cream, using Rule 17. 

(3.) Now standardize the skim-milk remaining under (1), or 
all the skim-milk on hand, as in the case under (2), using Rule 18 
to arrive at the amount of cream necessary to add in either ease. 
Make the necessary calculations to get the proper weights under 
the double standardization. 

(4.) Multiply the pounds of whole milk in the batch by the 
percentage of fat in the whole milk. Call the answer A. Multi- 
ply the pounds of skim-milk by the fat test of the skim-milk. 
Call the answer B. Multiply the pounds of cream required by 
the fat test of the cream. Call the answer C. Divide the sum 
of A, B and C by the ratio between the percentage of sugar and 
the percentage of fat in the product desired. The answer will 
be the number of pounds of sugar required for the total batch. 

Solution of Problem 21, based upon Formula 19: 

(1.) To calculate the pounds of cream required to standard- 
ize the whole milk. 







^ USR)-F]P 
G— (JR) 



(2.) To calculate the pounds of cream required to standard- 
ize the skim-milk. 

[(NXR)-K]L 
G— (JXR) 
(3.) To calculate the pounds of sugar to add. 

., jPXF) -f (LXK) + (OXG) 
u - Y 

Note — The value of in part (3) of the formula equals the 
value of in part (1) plus the value of in part (2) of the for- 
mula. 



258 STANlDARDiZING SWEETKNED CoNDENSED MitK; 

Problem 21, Example 22 : 





Pounds 


PER CENT 


Product3 


Fat 


M.S. N.F. 


Sugar 


T. S. 


Milk 


10,000 


3.20 


8.40 




11 . 60 


Skim-milk.. . 


600 


.16 


8.47 




8.63 


Cream 




26.38 


6.44 




32.82 


Composition 
desired 




8.00 


20.00 


44.50 


72.50 



Desired ratio of milk solids not fat to fat is 1 to .40. 
Desired ratio of sugar to fat is 1 to .1798, 

Solution of Problem 21, Example 22, based upon Rule 19 : 

A. Standardize the whole milk, using Rule 17 : 

(1.) To calculate the available fat in the cream. 

6.44 X .40 = 2.58, per cent of fat required to equalize the 
S. N. F. in cream. 
26.38 — 2.58 = 23.80, per cent of fat available for standardizing. 

(2.) To calculate the pounds of fat short. 
8.40 X -40 = 3.36, per cent of fat required. 
3.36 — 3.20 =: .16, per cent of fat short. 
10000 X .0016 = 16, pounds of fat short. 

(3.) To calculate the pounds of cream required. 
16 -^ .2380 = 67, or the pounds of cream required to standardize 
the whole milk. 

Should the whole milk require skim-milk instead of cream, use 
Rule 16 and subtract pounds of skim-milk required from the total 
pounds of skim-milk, and then standardize the balance of the 
skim-milk, using Rule 18. 

B. Standardize the skim-milk with cream, using Rule 18. 

(1.) To calculate the available fat in the cream. 
Same as under A (1) above = 23.80. 



Problems in Standardizing 259 

8.47 X .40 = 3.39, per cent of fat required. 
3.39 — .16 = 3.23, per cent of fat short. 
600 X .0323 = 19, pounds of fat short. 

(3.) To calculate the pounds of creaan required 

21 -=- .2380 = 81, pounds of cream required to standardize the 
skim-milk. 
C. Adding together answer obtained under A and B = 67 
plus 81 = 148, pounds of cream required to standardize the en- 
tire batch. 

(4.) D. To calculate the pounds of sugar required. 

10000 X .0320 = 32, pounds of fat in whole milk. 

600 X .0016 = 1, pounds of fat in skim-milk. 
(67 + 81) X .2638 = 39, pounds of fat in cream. 
320 4 1 -f 39 = 360, pounds of fat in entire batch. 
360 -f- .1798 = 2003, pounds of sugar required for total batch. 

Solution of Problem 21, Example 22, based upon Formula 19: 

(1.) To calculate the pounds of cream required to standardize 
the whole milk. 

[ (.0840 X .40) — .0320] X 10000 

= "i- 1 i = 67.20 

.2638— (.0644 X .40) 

(2.) To calculate the pounds of cream required to standardize 
the skim-milk. 

0^ [ (.0847 X .40) - .0016] X 600 _ ^^ ^^ 
.2638— (.0644 X .40) 

(3.) To calculate the pounds of sugar to add. 

(10000X.0320) + (600X.0016) + (148.56X.2638) _ 2003 



260 



Standardizing Sweetened Condensed Milk 



Proof of Problem 21, Example 22 ; 





Pounds 


POUNDS 


PER cent 


Products 


Fat 


M.S. 

n. f. 


Sugar 


T.S. 


Fat 


M.S. 
N. F. 


Sugar 


T.S. 


Milk. ... 


10000 


.320.00 


840.00 




1160.0 


3.20 


8.40 




11.60 


Skim- 
milk 


600 


.96 


51 




51.9 


.16 


8.47 




8.63 


Cream. . . 


148 


39.19 


9 




48.1 


26.38 


6.44 




32.82 


Sugar. . . . 


2003.0 






2003.0 


2003.0 






100.00 


100. 


Stand- 
ardized 
product. . 


12751 


360 


900 


2003.0 


3263.0 


2.82 


7.05 


15.70 


25 . 57 



The ratio of M. S. N. F. to fat obtained is 1 to .40. 
The ratio of sugar to fat obtained is 1 to .1798, 

STANDARDIZING SWEETENED CONDENSED MILK BEFORE 

CONDENSING. 

Problem 22: How to Calculate the Pounds of Sweetened Con- 
densed Skim-milk to Add to Whole Milk. 

Solution of Problem 22, based upon Rule 20: 

(1.) Divide the fat in the condensed skim-milk by the ratio 
between the S. N. F. and the fat in the product desired. Subtract 
the answer from the percentage of S. N. F. in the skim-milk. Call 
remainder A, or the percentage of milk S. N. F. in the condensed 
skim-milk available for standardizing. 

(2.) Divide the percentage of fat in the whole milk by the 
ratio between the S. N. F. and the fat in the product desired. Call 
the answer B. Subtract from B the percentage of S. N. F, present 
in the whole milk and multiply the remainder by the pounds of 
whole milk in the batch. Call the result C. 

(3.) Divide C by A. The answer will be the pounds of con- 
densed skim-milk required to standardize the batch to the re- 
quired ratio. 

(4.) Multiply the pounds of whole milk by the fat test of the 
whole milk. Call the product D. Multiply the pounds of con- 



Problems in Standardizing 



261 



densed skim-milk by the fat test of the skim-milk. Call the prod- 
uct E. Add D and E and divide the sum of the two by the ratio 
between the sugar and the fat in the product desired. The an- 
swer will be the pounds of sugar required for the total batch. 

Solution of Problem 22, based upon Formula 20: 

(1.) To calculate the pounds of sweetened condensed skim- 
milk required. 



L 



[(!-> 1^0-9 



(2.) To calculate the pounds of sugar required. 

(P X P) + (L^ X M) 



U = 



Problem 22, Example 23 : 



Y 



1 



- (L^ X 7.) 





Pounds 


PER CENT 


Products 


Fat 


M. S. N. F. 


Sugar 


T. S. 


Whole milk 


10000 


3.70 


8.40 




12.10 


Sweetened 
condensed 
Skim-milk 




1.00 


28.00 


42.00 


71.00 


Composition 
desired 




8.00 


20.00 


44.50 


72.50 



Desired ratio of M. S. N. F. to fat is 1 to .40. 
Desired ratio of sugar to fat is 1 to .1798. 

Solution of Problem 22, Example 23, based upon Rule 20: 

(1.) To calculate the percentage of available S. N. F. in the 
condensed skim-milk. 
1.00 -f- .4 = 2.50, per cent of milk S. N. F. required to equal- 
ize the fat in the skim-milk. 
28.00 — 2.50 = 25.5, per cent of milk S. N. F. available for stand- 
ardizing. 
(2) To calculate the pounds of milk S. N. F. short. 
3.7 -^ .4. = 9.25 per cent of milk S. N. F. required. 
9.25— 8.40=.85, per cent of milk S. N. F. short. 
10000 X -0085 = 85, pounds of milk S. N. F. short. 



262 



Standardizing Sweetened Condensed Milk 



(3.) To calculate pounds of condensed skim-milk required. 
85 -=- .255 = 333, pounds of condensed skim-milk. 

(4.) To calculate the pounds of sugar required. 
10000 X .037 = 370, pounds of fat in whole milk. 

333 X .01 = 3.3, pounds of fat in condensed skim-milk. 
370 -f- 3.3 =: 373.3, total pounds of fat in batch. 
373.3-^-.1798 =: 2076, pounds of sugar required for total batch. 
333 X .42 = 140, pounds of sugar added in condensed skim- 
milk. 
2076 — 140 = 1936, pounds of sugar to be added to whole 

milk. 
Solution of Problem 22, Example 23, based upon Formula 20 : 

(1.) To calculate the pounds of sweetened condensed skim- 
milk required. 

.0370 

" X 10000 

L^ = ^-^ :^ = 333.3 



r^«-.0840^ 
, V .40 J 



.2800- 



.0100 



u = 



.40 

(2.) To calculate the pounds of sugar required. 
(10000 X .0370) + (333.3 X .0100)1 



.1798 



(333.3 X .42) = 1936. 



Proof of Problem 22, Example 23 : 





Pounds 


POUNDS 


PER CENT 


Products 


Fat 


M.S. 

N. F. 


Sugar 


T. S. 


Fat 


M.S. 

n. f. 


Sugar 


T. S. 


Milk.... 


10000 


370 


840 




1210 


3.70 


8.40 






Sweet'd 
Cond. 
Skim milk 


333 


3.3 


93 


140 


236 


1.00 


28.00 


42.00 


71.00 


Sugar . . . 


1936 






1936 


1936 






100.00 


100.00 


Stand- 
ardized 
product. . 


12269 


373.3 


933 


2076 


3382 


3.00 


7.51 


16.72 


27.23 



Ratio of M. S. N. F. to fat obtained is 373.3 -^ 933 = .40. 
Ratio of sugar to fat obtained is 373.3 -^ 2076 = .1798, 



pROBtSMs IN Standardizing 2oj 

STANDARDIZING SWEETENED CONDENSED MILK BEFORE 
CONDENSING. 

Problem 23 : How to Calculate the Pounds of Unsweetened Con- 
densed Skim-milk to Add to Whole Milk. 

Solution of Problem 23, based upon Rule 21 : 

(1.) Divide the percentage of fat in the unsweetened con- 
densed skim-milk by the ratio between the S. N. F. and the fat de- 
sired. Subtract the answer from the S. N. F. in the unsweetened 
condensed skim-milk. Call the remainder A, or the percentage of 
S. N. F. available for standardizing in the unsweetened condensed 
skim-milk. 

(2.) Divide the percentage of fat in the whole milk by the 
ratio between the S. N. F. and the fat, in the product desired. 
Call the answer B. Subtract B from the percentage of S. N. F. 
present in the whole milk, and multiply the remainder by the 
pounds of whole milk in the batch. Call the result C. 

(3.) Divide C by A. The result will be the pounds of skim- 
milk required to standardize the batch to the required ratio. 

(4.) Multiply the pounds of whole milk by the fat test of the 
whole milk. Call the product D. Multiply the pounds of un- 
sweetened condensed skim-milk by the fat test of the unsweet- 
ened condensed skim-milk. Call the product E. Add D and E, 
and divide the sum by the ratio between the sugar and the fat in 
the product desired. The answer will be the pounds of sugar re- 
quired for the total batch. 

Solution of Problem 23, based upon Formula 21 : 

(1.) To calculate the pounds of unsweetened condensed skim- 
milk required. 

.. [(i-.)p].(,.«,) 

(2.) To calculate the pounds of sugar required. 

^^ (PXF) + (QXGM 



264 Standardizing SwEKTrned Condensed Milk 

Problem 23, Example 24: 





Pounds 


PER CENT 


Products 


Fat 


M. S. N. F. 


Sugar 


T. S. 


Milk 


10000 


3.70 


8.40 




12.10 


Unsweetened 
condensed 
skim-milk. . . 




.05 


29.95 




30.00 


Composition 
desifed after 
condensing.. 




8.00 


20.00 


44.50 


72.50 



Desired ratio of M. S. N. F. to fat is 1 to .40. 
Desired ratio of sugar to fat is 1 to .1798. 

Solution of Problem 23, Example 24, based upon Rule 21 : 

(1.) To calculate the available S. N. F. in the condensed 
skim-milk. 

.05-^.4=. 13, per cent of milk S. N. F. required to equalize 
the fat in the condensed skim-milk. 
29.95 — .13 = 29.82, per cent of milk S. N. F. available for stand- 
izing. 

(2.) To calculate the pounds of milk S. N. F. short. 
3.7 -f- .4 = 9.25, per cent of milk S. N. F. required. 
9.25 — 8.40= .85, per cent of milk S. N. F. short. 
10000 X .0085=85, pounds of milk S. N. F. short. 

(3.) To calculate the pounds of condensed skim-milk re- 
quired. 

85-^.2982=285, pounds of condensed skim-milk required. 

(4.) To calculate the pounds of sugar required. 
10000 X -0370 = 370, pounds of fat in the whole milk. 
285 X -0005 = .14, pounds of fat in condensed skim-milk. 
370.14-:- .1798 =2059, pounds of sugar required for total batch. 



Problems in Standardizing 265 

Solution of Problem 23, Example 24, based upon Formula 21 : 

(1.) To calculate the pounds of unsweetened condensed skim- 
milk required. 

^_ [(^°-O84o)xlOO00] _ 

(2.) To calculate the pounds of sugar required. 

^ ^ (10000 X .0370) + (285 X .0005) ^ ^059 
.1798 
Proof of Problem 23, Example 24: 





Pounds 


POUNDS 


PER CENT 


Products 


Fat 


M. S. 
N. F. 


Sugar 


T. S. 


Fat 


M.S. 

N. F. 


Sugar 


T.S. 


Milk. ... 


10000 


370 


840 




1210 


3.70 


8.40 




12.10 


Unsweet- 
ened con- 
densed 
skim-milk 


285 


.14 


85 




85.14 


.05 


29.95 




30.00 


Sugar. . . . 


2059 






2059 


2059 






100.00 


100.00 


Stand- 
ardized 
product. . 


12344 


370.14 


925 


2059 


3354 


3.00 


7.50 


16.68 


27.10. 



Ratio of M. S. N. F. to fat obtained is 370.15 ^ 925 = .40. 
Ratio of sugar to fat obtained is 370.15 ^ 2059 — .1798. 

STANDARDIZING SWEETENED CONDENSED MILK BEFORE 

CONDENSING. 

Problem 24: How to Calculate the Pounds of Unsweetened Con- 
densed Whole Milk to Add to Whole Milk. 

Solution of Problem 24, based upon Rule 22 : 

(1.) Multiply the pounds of whole milk in the batch by the 
test of the whole milk. Call the answer A. Multiply the pounds 
of condensed whole milk in the batch by the fat test of the con- 
densed whole milk. Call the answer B. Add A to B. Call the 



266 Standardizing Sweetened Condensed Milk 

sum C, or the pounds of fat in the mixed batch. Divide C by the 
weight of whole milk and condensed whole milk in the batch. 
Call the answer D or the percentage of fat in the mixed batch. 
Multiply the pounds of whole milk by the percentage of S. N. F. 
in the whole milk. Call the answer E. Multiply the pounds of 
condensed whole milk in the batch by the percentage of S. N. F. 
in the batch. Call the answer F, or the pounds of S. N. F. in the 
condensed whole milk. Add E and F. Call the sum G, or the 
pounds of S. N. F. in the mixed batch. Divide G by the pounds 
of whole milk plus the pounds of condensed whole milk in the 
batch. Call the answer H, or the percentage of S. N. F. in the 
mixed batch. Divide the percentage of fat in the unsweetened 
condensed skim-milk by the ratio between the S. N. F. and the fat 
in the product desired. Call the answer I. Subtract I from the 
percentage of S. N. F. in the unsweetened condensed skim-milk. 
Call the remainder J. 

(2.) Divide the percentage of fat in the mixed batch by the 
ratio between the S. N. F. and the fat in the product desired. Call 
the answer K. Subtract from K the percentage of S. N. F. in the 
mixed batch. Call the remainder L. Multiply the total pounds 
of whole milk and condensed whole milk in the batch by L. Call 
the product M, or the pounds of fat short. 

(3.) Divide M by the percentage of S. N. F. available for 
standardizing in the condensed skim-milk. Call ansM-er N, or the 
pounds of condensed skim-milk required. 

(4.) Multiply the total pounds of whole milk and condensed 
whole milk by the average fat test of the mixed batch. Call the 
product 0. Multiply the pounds of unsweetened condensed 
skim-milk by the fat test of the unsweetened condensed skim-milk. 
Call the product P. Divide the sum of and P by the ratio be- 
tween the sugar and the fat in the product desired. The answer 
will be the number of pounds of sugar required for the total batch. 
Solution of Problem 24, based upon Rule 22 : 

(1.) To calculate the percentage of fat in the mixed batch. 

(PF) + (DK^) 

Ql ■ 

^ ~" P + D 



Problems in Standardizing 



267 



(2.) To calculate the percentage of S. N. F. in the mixed 
batch. 



V^ 



(PS) -f (DS=^) 



P + D 

(3.) To calculate the pounds of unsweetened condensed skim- 
milk required. 

«=[(f-^'>l^('-f) 

(4.) To calculate the pounds of sugar required. 

_ (S^P) + (G^Q) 

Problem 24, Example 25: 





Pounds 


PER CENT 


Products 


Fat 


M. S. N. F. 


Sugar 


T. S. 


Milk 


10000.0 


3.70 


8.40 




12.10 


Condensed 
Whole milk 


1000.0 


10.00 


28.00 




38.00 


Condensed 
Skim-milk. . . 




.05 


29.95 




30.00 


Composition 
desired after 
condensing. . 




8.00 


20.00 


44.50 


72.50 



Desired ratio of fat to milk solids not fat is .40 to 1. 
Desired ratio of sugar to fat is ,1798. 

Solution of Problem 24, Example 25, based upon Rule 22 : 

(1.) To calculate the average test of the mixed milk. 
100000 X .0370 = 370, pounds of fat in whole milk. 

1000 X -10 = 100, pounds of fat in condensed whole milk. 

370 -f- 100 = 470, pounds of fat in mixed batch. 

470 H^ 11000 — 4.27, per cent of fat in mixed batch. 
10000 X .0840 = 840, pounds of S. N. F. in whole milk. 



268 Standardizing Sweetened Condensed Milk 

1000 X .28 = 280, pounds of S. N. F. in condensed whole 

milk. 
840 + 280 — 1120, pounds of S. N. F. in the mixed batch. 
10000 4- 1000 = 11000, total of pounds whole milk and con- 
densed whole milk in the batch. 
1120 -^ 11000 = 10.18, per cent of S. N. F. in mixed batch. 
.05 H- .4 = .13, per cent milk S. N. F. required to 

equalize the fat in the skim-milk. 
29.95 — .13 := 29.82, per cent S. N. F. available in the skim- 
milk for standardizing. 

(2.) To calculate the pounds of milk S. N. F. short. 
4.27 ~ .40 — 10.68, per cent of milk S. N. F. required. 
10.68 — 10.18 = .50, per cent of milk S. N. F. short. 
10000 X .005 = 50, pounds of milk S. N. F. short. 

(3.) To calculate the pounds of condensed skim-milk required. 
50-^-.2982 =: 166, pounds of condensed skim-milk required. 
(4.) To calculate the pounds of sugar required. 
11000 X .0427 = 470, pounds of fat in the mixed batch. 

166 X .0005 = .08, pounds of fat in the condensed skim-milk. 
470 ^- .1798 = 2614, pounds of sugar required for the total 

batch. 

Solution of Problem 24, Example 25, based upon Formula 22 ' 
(1.) To calculate the percentage of fat in the mixed batch. 

(10000 X .037) + (1000 X -10) 
10000 -+- 100 

(2.) To calculate the percentage of S. N. F. in the mixed 
batch. 

_ (10000 X .084) + (1000 X .28) _ 
^'- 10000 + 1000 ~ -=10.18 

(3.) To calculate the pounds of unsweetened condensed skim- 
milk required. 

r^:?i?^ — .lois'jx looool 

Q- ^005 -^«« 

.2995 

.40 



Problems in Standardizing 
(4.) To calculate the pounds of sugar required. 

(11000 X .0427) + (166 X -0005 



269 



^ .1798 

Proof of Problem 24, Example 25 : 



= 2614. 







POUNDS 


PER CENT 


Products 


Fat 


M. .". 
N. F. 


Sugar 


T. S. 


Fat 


M.S. 
N.F. 


Sugar 


T. S. 


Milk .... 


10000.00 


370.0 


840.00 




1210.0 


3.70 


8.40 




12.10 


Cond. 
whole 
milk 


1000.00 


100.0 


280.00 




380.0 


10.00 


28.00 




38.00 


Cond. 
skim-milk 


166.0 


.08 


49.72 




49.8 


.05 


29.95 




30.00 


Sugar 


2614.0 






2614.0 


2614.0 






100.00 


100.00 


Stand- 
ardized 
product. . 


13780.0 


470.08 


1169.72 


2614.0 


4253 . 8 


3.41 


8 50 


18.96 


30.87 



Ratio of S. N. F. to fat obtained is 1 to .40. 
Ratio of sugar to fat obtained is 1 to .1798. 



STANDARDIZING SWEETENED CONDENSED SKIM-MILK 
BEFORE CONDENSING 

Problem 25: How to Calculate the Pounds of Sugar to Use in 
Sweetened Condensed Skim-milk. 

Solution of Problem 25, based upon Rule 23 : 

(1.) Multiply the pounds of skim-milk in the batch by the to- 
tal solids test of the skim-milk. Multiply the answer by the ratio 
between the total milk solids and the sugar in the product desired. 
The result will be the pounds of sugar to add to the entire batch. 

Solution of Problem 25, based upon Formula 23. 



270 Standardizing Sweetened Condensed Mii,k 

Problem 25, Example 26 : 



Products 


Pounds 


M. S. N.F. 


Sugar 


T. S. 


Skim-milk 


10000 


8.83 




8.83 


Composition 
desired 




28.00 


42.00 


70.00 






Desired ratio of milk solids to sugar is 1 to 1.50. 



Solution of Problem 25, Example 26, based upon Rule 23 : 

(1.) To calculate the pounds of sugar required. 
10000 X .0883 = 883, pounds of milk solids in the skim-milk. 
883 X 1-50 =1325, pounds of sugar to use. 
Condense the batch sufficiently high to provide the proper fac- 
tor of safety. 

Solution of Problem 25, Example 26, based upon Formula 23 : 

U = (10000 X .0883) X 1.5 = 1325 

Proof of Problem 25, Example 26 : 







POUNDS 


PER CENT 


Products 


m.s.n.f 


Sugar 


T.S. 


M.S.N.F. 


Sugar 


T.S. 


Skim-milk 


10000 


883 




883 


8.83 




8.83 






Sugar 


1325 




1325 


1325 




100.00 


100.00 


Standardized product 


11325 


883 


1325 


2208 


7.37 


16.42 


23.79 



Condense the batch high enough to provide the proper factor 
of safety. 

TABLES FOR ASCERTAINING SUGAR REQUIRED. 

The quantity of sugar to use for any corresponding weight of 
T. S. when manufacturing sweetened condensed skim-milk, can be 
ascertained from tables compiled for any composition desired, and 
for any quantity range necessary. The use of such tables helps 
to prevent errors, and it saves calculations. It makes it neces- 



Sugar Tables 



271 



sary in practice simply to ascertain the pounds of total solids m 
the batch, and then by reference to the table, to obtain the weight 
of sugar to produce a product of the composition desired. 

In Problem 25, Example 26, the product is to have a composi- 
tion of 28.00 per cent total milk solids and 42.00 per cent sugar, or 
in the ratio 1 part T. M. S. to 1.5 parts sugar. This is the composi- 
tion desired in the case of nearly all sweetened condensed skim- 
milk manufactured in the United States. In view of the fact that 
the above ratio is so simple, but little time, if any, could be saved 
by compiling tables for this composition. For any who might de- 
sire to compile a table either for a product of the above composi- 
tion, or of any composition desired, specimen Table 43 has been 
prepared. 

TABLE 43. 

Ratios between pounds of total milk solids in the batch, and pounds of 
sugar required, to make sweetened condensed skim-milk testing 28.00 per cent 
total milk solids, 42.00 per cent sugar, and 70 per cent total solids. 



Pounds 
T.M.S. 


Pounds 
Sugar 


Pounds 
T.M.S. 


Pounds 
Sugar 


Pounds 
T.M.S. 


Pounds 
Sugar 


Pounds 
T.M.S. 


Pounds 
Sugar 


Pounds 
T.M.S. 


Pounds 
Sugar 


100 


150 


250 


375 


500 


750 


1000 


1500 


2500 


3750 


101 


152 


251 


377 


501 


752 


1001 


1502 


2501 


3752 


102 


153 


252 


378 


502 


753 


1002 


1503 


2502 


3753 


103 


155 


253 


380 


503 


755 


1003 


1505 


2503 


3755 


104 


156 


254 


381 


504 


756 


1004 


1506 


2504 


3756 


105 


158 


255 


383 


505 


758 


1005 


1508 


2505 


3758 


106 


159 


256 


384 


506 


759 


1006 


1509 


2506 


3759 


107 


161 


257 


386 


507 


761 


1007 
1008 


1511 


2507 


3761 


108 


162 


258 


387 


508 


762 


1512 


2508 


3762 


109 


164 


259 


389 


509 


764 


1009 


1514 


2509 


3764 



CHAPTER XIII 

THE COMPOSITION AiND STANDARDIZATION 
OF ICE CREAM MIXES 

SUGGESTED COMPOSITIONS OF VARIOUS ICE CREAM MIXES. 

It is possible to compound satisfactory ice cream mixes 
varying widely in composition, and there is probably no other 
dairy product that shows such large variations in composition 
both in the same and in the different localities, and even in the 
product of any single manufacturer where no attempt is made 
at exact chemical control. This is so because the ingredients 
used in making up an ice cream mix are so different in character 
and each fluctuates so much in composition. Again, it is some- 
times desirable to manufacture more than one quality of ice 
cream. Table 43 gives the composition of thirteen different ice 
cream mixes. The proper composition can be selected from the 
list to meet the needs of manufacturers in all localities. Ice cream 
of these several compositions is now manufactured in many 
different localities, and all have given satisfactory products. 

THE PHYSICAL AND CHEMICAL PROPERTIES OF VARIOUS 
ICE CREAM MIXES. 

The physical and chemical properties of nine of the most com- 
mon composition of ice cream mix are given in Table 44. Unless 
otherwise indicated, the values named are based upon actual 
determinations. One batch of mix corresponding to each composi- 
tion named, was carefully compounded and in turn these were 
used to make the various determinations. The raw materials 
used to compound these mixes consisted of cream testing 36.00 
per cent of fat, superheated bulk condensed whole milk testing 
8.00 per cent of fat, sugar and gelatin. 

[272] 



Composition of Mixes 



276 



TABLE 43. 
Suggested Compositions &f Ice Cream Mixes. 









PER CENT 






No. of Mix 












Fat 


Milk 
S. N. F. 


Sugar 


Gelatin 


T. S. 


1 


8.00 


11.50 


13.00 


.50 


33.00 


2 


8.00 


12.50 


13.00 


.50 


34.00 


3 


8.50 


12.00 


13.00 


.50 


34.00 


4 


9.00 


11,50 


13.00 


.50 


34.00 


5 


10.00 


10.50 


14.00 


.50 


35,00 


5A 


11.00 


10.50 


14.00 


.50 


36.00 


6 


12.00 


8.50 


14.00 


.50 


35.00 


7 


12.00 


9.50 


14.00 


.50 


36.00 


7A 


13.00 


8.50 


14.00 


.50 


36.00 


7B 


14.00 


• 9.50 


14.00 


.50 


38.00 


7C 


15.00 


8.50 


14.00 


.50 


38.00 


8 


16.00 


7.50 


14.00 


.50 


3S,00 


9 


18.00 


7.50 


14.00 


.50 


40.00 



Composition Ratios. In standardizing ice cream mix it is 
usually necessary to know the ratio between the fat and the 
M. S. N. F., or that between the fat and the T. S. Both of these 
ratios are given for each of the nine compositions of mix. Ob- 
viously, there is quite a variation in these several ratios. 

Viscosity. This was determined by means of the Mojonnier- 
Doolittle viscosimeter described in Chapter XVII. The viscosity 
was determined at various temperatures immediately after pre- 
paring at 40° F., after aging 24, 48, and 72 hours each respec- 
tively. The results of this experiment prove: (1) The viscosity 
of all mixes regardless of composition, increases as the holding 
temperature decreases. (2) Viscosity in the case of freshly pre- 
pared mix is the same at equal temperatures, regardless of 
composition when compounded from the same products. (3) 
viscosity increases with the age of the mix. The increase with 
age is much greater in the case of ice cream mix high in milk 
solids not fat. This is no doubt largely due to the action of the 
acid that develops during aging, upon the casein and albumin 
contained in the mix. The gelatin content of the mix may also 



274 Ice Cream Mixes 

exert a large influence upon its viscosity. The quality and quan- 
tity of the gelatin used determines largely the extent of its effect 
upon the viscosity of the mix. 

Titratable Acidity. This was usually higher both immediately 
after preparing, and also after aging, in the case of all mixes, 
containing the higher percentage of milk solids not fat. There 
is a close correlation between titratable acidity and viscosity. 

The percentage of titratable acidity in fresh ice cream mix is 
dependent upon the quantity of acid contained in the raw mater- 
ials used, and it is derived chiefly from the milk solids not fat in 
the raw materials. 

There is no general agreement as to what constitutes thcmost 
desirable percentage of acidity in ice cream mix at the time of 
freezing. A mix containing 12.00 per cent of milk solids not fat 
made from whole milk testing .16 per cent of titratable acidity 
and containing 8.60 per cent of milk solids not fat and from sweet 
butter without acid should test after condensing about .23 per 
cent of titratable acidity. Controlling the acid content of the mix 
between close limits would no doubt favorably influence the uni- 
formity of the flavor. The higher the content of milk solids not 
fat in the mix, the higher will be the titratable acidity in the 
same, when the same raw products are used. 

Specific Gravity. This value increases as the temperature 
decreases, regardless of composition. Changes in composition are 
immediately reflected in the specific gravity. Obviously the 
higher the fat content the lower the specific gravity for any given 
percentage of S. N. F. 

Weight per U. S. Gallon of Mix. This is based upon the 
specific gravity determinations at the various temperatures, com- 
pared with water weighing 8.34 pounds per U. S. gallon. 

Weight per U. S. Gallon of Ice Cream. The weight of one 
gallon of mix at 40" F. was taken as unity. The weight of one 
gallon of ice cream at various percentages of overrun was calcu- 
lated from the above unit basis. The results in Table 44 indicate 
the differences in the weight of ice cream of various compositions, 
at the same overrun. 

Available Heat of Combustion. This is given upon the basis 
both of one pound of mix, and of one Ur S. gallon of ice cream 



Specific Heat and Freezing Points 275 

at 100 and at 80 per cent of overrun, respectively expressed as 
calories and as B. T. U. The factors given by Richmond^ were 
used. These were based upon the combustion of the three con- 
stituents in the human body, and take into consideration that 
portion of the protein which is not combusted, but which is 
voided in the form of urea. The gelatin was added to the milk 
proteins. The factors are as follows : — 

Available heat of combustion one kilogram butter fat=9.230 
Calories. 

Available heat of combustion one kilogram milk sugar=3.950 
Calories. 

Available heat of combustion one kilogram cane sugar=3.955 
Calories. 

Availiable heat of combustion one kilogram protein=:4.970 
Calories. 

Specific Heat. This was calculated from the values given by 
Hammer & Johnson.- The calculations were all made upon the 
basis of a temperature of zero degrees F., using the following 
formula : — 

(Per cent fat \ ,._ , /lOO^ — ^ per cent fat \ 
— 100 — ) "^ V 100 ) -^^^ 

It was assumed in these calculations that the specific heat of 
the cane sugar added to the mix, was the same as the specific heat 
of milk serum. 

Freezing Point. The freezing points were determined by the 
depression method using a Beckman thermometer. This value 
showed comparatively little fluctuation. The largest part of the 
depression is caused by the milk sugar and the cane sugar that 
are in the solution. A solution containing 6.00 per cent milk 
sugar and 14.00 per cent cane sugar was found to have a freezing 
point of 29.38° F. 

Calculated upon the basis of the water content only, the sum 
of the percentages of milk sugar and the cane sugar is proportion- 
ately larger than in ice cream mix. Mix No. 1 contains a total 
of about 19.21 per cent of milk sugar and cane sugar. Calculated 
upon a water content of 67.00 per cent this is equivalent to a 
concentration of 22.25 per cent, based upon the water content 
only, or 28.67 parts of the two sugars per 100 parts of water. 



276 Ice Crram Mixes 

Heat Units Required to Melt Ice Cream. The feeling of cold- 
ness experienced in eating ice cream is due to the heat units that 
are absorbed in the mouth due to the melting of the ice cream. 
This is the sum of the normal heat and the latent heat. The cal- 
culation is shown in the case of ice cream containing 100 per cent 
overrun, and therefore weighing 4.60 lbs. per U. S. gallon, raised 
in temperature from 20° F. to 60° F. The method of calculation 
used is illustrated in the case of ice cream mix No. 1 as follows : — 

Normal heat=(4.60X.900) X 40=165.6 B. T. U. 
Latent heat=(4.60X.6700) Xl44=443.8 B. T. U. 



Total =609.4 B. T. U. 

These values in this table explain why the feeling of coldness 
varies with different ice creams. Ice cream made from mix No. 9 
will feel about 12.00 per cent warmer to the tongue than ice 
eream made from mix No. 1. 

Nutritive Ratios, These are expressed from the standpoints 
of both, composition in the ratio : — fat : sugar : protein ; and 
available heat units in the ratio: — protein : ( f at -j- sugar). 

It is most significant that it is possible to compound a high 
quality of ice cream mix in Avhich the various constituents are in 
very nearly the right proportions to best stimulate growth and 
sustain life. Extremes in composition do not produce this favor- 
able result. 

For children, ice cream testing 10.00 per cent fat; 10.50 per 
cent milk solids not fat; 14.00 per cent sugar and .50 per cent 
gelatin; — totaling 35.00 per cent total solids, most nearly ap- 
proaches the theoretical requirements of a properly balanced 
ration. For adults ice cream testing 8.00 per cent fat; 12.50 per 
cent milk solids not fat; 13.00 per cent sugar, and .50 per cent 
gelatin, — totaling 34.00 per cent total solids, approaches very 
closely the theoretical requirements. 

The above ratios apply only when ice cream is consumed alone. 
It is very frequently consumed as a dessert, in which case its 
nutritive value influences the balance of the diet. The questions 
of flavor and palatability also' exert an important influence upon 
this problem. Ice creams rich in butter fat are preferred by 



Physicai, and ChEmicai. Prope;rtie;s 



277 



TABLE 44. 
The Physical and Chemical Properties and the Nutritive Ratio of Ice Cieam 

Mix. 



! 

.9 

5 

< 
1 
1 


After 
Aging 

72 
Hours 




OOOOCOiOOOO^O 




ki bC ^ 

"■^22 2 








COC»5«>CCCC(MC-»N(M 




•o3 Ml 

■Sfc-g 

lea 

a f^ 






§ 

1 
1 


I. M E 


o 


oo.-HOr-to>oi«toco 




§ 


lOOOOOiOiOiOO 






OU3iOOOIO»CO»C 


■s 

> 






s 


ooooooooo 
cccccccocccoecccco 


s 


10 10IO»0101010"5»0 


o 


O— lOOOOOOO 


o 


cocDcotOcoco:o:DeD 




.2 

K 

" a 

o 

1 


•IS- 


1250 
2500 
0000 
7778 
5000 
9167 
0000 
3750 
2222 


Tji-^^TOCCC^COC^IM 






4375 
5625 
4118 
2778 
0500 
7083 
7917 
4688 
4167 






ii 

IJ 

s 


5 


OOOOOOOOO 

OOOOOOOOO 


r^coeocDiOto-^c^o 




ooooooooo 
ooooooooo 

co-^'-^'^'Oiocdooo 




ooooooooo 




t-. 

3 
CO 


ooooooooo 
ooooooooo 




cc 


ooooooooo 
u^ioo«raoioio>n« 


— IMCVl— '000 0-. t^l^ 


1 


ooooooooo 

OOUOOOOOOO 


OOOOOOOIOCJC^COOO 










f-ic^jco-^ioor^oooi 



Is 

03 


o 


9.19 
9.21 
9.20 
9.13 
9.18 
9.09 
9.13 
9.05 
9.04 


o 


rtrt.-.^rtooo>aj 


OCiOOiOSOOQOOO 


■•f 


00(MO«0><^100^00 

OOOOSOSOOOSOOt^ 


OOOOJOOOOOOQOOOOO 


°g 
"IB 

-a g 

ti 

1 

o 

to 

i 


■* 


1.1022 
1.1043 
1.1031 
1.0954 
1.1005 
1.0899 
1.0946 
1.0848 
1.0841 


o 


1.1016 
1.1030 
1.1010 
1.0949 
1.0985 
1.0880 
1.0928 
1.0835 
1.0811 


o 


1.0957 
1.0978 
1.0970 
1.0923 
1.0927 
1.0822 
1.0867 
1.0764 
1.0749 


o 

o 


tDi:Dr>-oas»oosi>-oo 
r^oco>0'<**coi>-t~*-<*< 

ooooooooo 


o 


^OOOCMOt^t^O 
COOOCOOasOO(M.-"QO 

ooooooooo 


o 


1.0772 
1.0815 
1.0917 
1.0738 
1.0728 
1.0616 
1.0667 
1 . 0558 
1.0526 


Is 

.2o 

a 

o 




ooooooooo 
ooooooooo 


t^tO^DOi^iO'^C^O 




ooooooooo 
ooooooooo 


CO'<*<'*'>*iO»OCOOOO 




ooooooooo 




1 


ooooooooo 

ooooooooo 


c^cococo-^^-^-^-^ 






ooooooooo 

iOiOO»CO»OiOiO»0 


^csc^ii— oooa>i>»t* 


1 


ooooooooo 

<00ir300>0000 


coooooooc^c^iooo 




:^l 


T-KMCO^iftOr-OQOi 



278 



Ice Cream Mixes 



TABLE 44 (Continued). 





a 
O 

ii 
1l 

£ 3 

■f 

■< 

C 
3 

> 

o 

1 

c 

c 

(5 

S 3 

c 
o 

B 

_o 
15 

o 

oi 

1= 

B 
O 




OO^COiCOOOO^CO 
CM O rJH OS CD,'* C<I '^J* t-^ 




CCCCCOCOCOCOCC'***'^ 




o 

o 


78833 
80664 
81850 
83034 
87204 
91938 
93756 
06870 
15244 




.. 




o 


O-^ CO C. CM CO CI fO CO 
^.-H,-HO^OOOO 




CDCDCOCOCDCOCOCDCO 




o 


-*fCO»C^HCOCii-HCOiO 

i>-t^t^t~^t^cor^coco 




iCiOiOiOiO»CiOiO»0 




o 


'-^CMi-Hb-OtOt^CMCvl 

^TpTjiCOTjiCCCOeOCO 




lOiOiCiOOiOiCiOiO 




o 


W(M.-'I^O»C(^COCM 

t_,^rtO^OOOO 




»cicutnoir5ic»oio»o 




o 

0-. 


-^J^iC-^^COOO^COco 

oocooocooot'-oor^t-^ 




"<1*Tt4TpTji'rJ4Tt4Tj<-<*4'^ 




i 


ooor-c:i»ot^cocM 

COCOCOiOiOiO*0»0»0 




«^T}1'*'^Ttl'^^TJlT}4 




o 


OOOOOOiOt-COiOi-HO 
CO CO CO CO CO CO CO CO CO 




'*Tj1-«*1'^Tt"Tp-«*4-^f^ 




i 




ooooooooo 
ooooooooo 




r^cococoio»0'*c3 

COCOCDUDCCCOCOCOCD 




CO 


ooooooooo 
ooooooooo 




CO'^'^Ji-.SllOiOCOOOO 
COCCCOCOCOOOCOCO'* 




i.g 


OOOOOOOOO 

ir3iOkoiow3ur5coiO»o 








02 


OOOOOOOOO 
OOOOOOOOO 
eOCOCOCO'^'rJH',^.^^' 










ooooooooo 




»-<CMCMi-hOOOO'. t-t^ 




-« 
fe 


S§g§§§8§S 




0000Q0C5OCMC<)C000 




c 


■^1 


f-icMcO'^iccor^ooci 



Nutritive Ratio 

Expressed as 

Available Heat 

Units in the Ratio:- 

Protein : (Fat + 

Sugar) 
Thporeticnl for 


&«? 

<'° 

"3 
-a 
•< 


r~c-jcort-*(MCKi.-<o 


r^t^t^oooc^-Hcot^ 




Nutritive Ratio 
Fat: Sugar: Protein 
Theoretical 
for Infant 
(Richmond P. 336) 
2:4:1 
Theoretical 




OOOOOC^ICSWQO 


OOCicDCOOii-HCqcO 
-^- TJH ^44 tH CO CC CO csi C^ 


C<lCq(M(MCqC<)lMMN 


Heat Units Required 
to Raise Temperature 

from 20° F. to 60° F. 

in One U. S. Gallon 
Ice Cream Containing 
100 Per Cent Overrun. 


P5 


^OOOOQOOOtOt^lOI^ 


OC<l(MOO-*cniOt--!N 
(30005C50000COiO 


O 


OOOOOOOO— 100 
>OCT.OClQOtOOOCq 


CO^H^^OOSOOt^cOOS 




Freez- 
ing 
Points 

Temp. 


i; 


t^O>OI^>O00Ot^O 

(NO^c^ic^-^-^coeo 


OOOOOOOOQOOOOOOOOO 


Specific 
Heat at 

0° F. Cal- 
culated 
from 
Factors:- 

S.H. = (Fat 




OOOOlO^^r^r-^'-" 

ooOiOiOioooocoira 

O O 00 00 00 00 00 00 00 


Available Heat of Combustion 

One Gallon Frozen Ice Cream at 

Different Per Cents of Overrun 

Calculated 


§ 




oooo50"^'MOcor^ 

OSCOiOt^cO-^OOOOOi 


iOcotO':or^oooo^o4 
„ _ rt « r-, « .^ es cs 


"a 


00 O C*! O^ t>- C^ CO »0 lO 

c^^(^^ooo•^■^":)^^oo 

O^^C^-^COt^COI-^ 


Tj*-<j*T}<-^-^-<j«^ir5io 


o 
o 




14.38 
14.72 
14.94 
15.06 
15.88 
16.60 
17.00 
19.22 
20.68 


s 

O 


3.626 
3.710 
3.765 
3.794 
4.002 
4.183 
4.284 
4.841 
5.208 


a 

o 

a 


"5 


67.00 
66.00 
66.00 
66.00 
65.00 
65.00 
64.00 
62.00 
60.00 


M 

H 


OOOOOOOOO 

ooooooooo 


COT)<rt1*^»Oif30000 
COCOCOCOCOCOCOCO-* 


4.3 


1010»0»0»010»0«OW3 




3 


ooooooooo 
ooooooooo 




03 


ooooooooo 


rHC<l<MrtO00Ot^t>. 




ooooooooo 

OOiOOOOOOO 


000000050C^C<ieOOO 




Z°S 




rtCMco-*iraot~oo3i 



Relative Commercial Merit 279 

many because of their different, palatability as compared with 
those low in fat. Likewise the relative vitamine content is a 
very important factor. As yet no exact methods have been 
elaborated for measuring these constituents, but in all proba- 
bility the most favorable vitamine content exists in creams that 
approach in composition the theoretical nutritive ratios. Ice 
cream of this composition is rich in both fat soluble A and water 
soluble B, but like whole milk itself, it is deficient in water 
soluble C vitamin, 

RELATIVE COMMERCIAL MERIT OF ICE CREAM MIX OF' 
VARIOUS COMPOSITIONS. 

From a commercial standpoint, the composition of the ice 
cream mix is an extremely important factor. First in importance 
is the influence of composition in stimulating consumption and 
creating demand. Second, the factor of cost per gallon as influ- 
enced by composition. Increase in fat content and unit cost, 
practically parallel each other. The manufacturer must deter- 
mine what composition will best stimulate demand, at the same 
time giving due regard to costs. Frequently the manufacturer 
is limited to a range of composition that is arbitrarily determined, 
either or both, by legal standards or by competitive trade 
standards. The unit cost per gallon of ice cream is of more 
interest to the manufacturer than the unit cost of the mix itself. 
The unit cost of the ice cream is determined very largely by the 
overrun. Ice cream made from mix of low composition is not 
satisfactory if the overrun is too high. Within reasonable limits 
the best ice cream is obtained when prepared from mix of high 
quality, accompanied by a liberal overrun. The improvement in 
the quality is obtained at practically no increase in cost. Finally 
there is the great influence of composition upon manufacturing 
operations with particular reference to its effect upon the over- 
run. This will be discussed further in Chapter XV. 

Table 45 gives detailed information upon the above dis- 
cussion in the case of ice cream mixes of nine different composi- 
tions. The cost figures as given are purely arbitrary, and 
obviouslj^ would fluctuate with market changes in the case of the 
products involved. 



280 



Ice Cream Mixes 



TABLE 45. 
Commeicial Factors as Influenced by Composition of Ice Cream Mix. 





< 


s 

m 

o 

O 
"3 

'o 

L< 

OJ 

a 
a 

o 
o 

< 


a 

cS 
(U 
t-i 

o 

(D 

U 

'3 

(U 

a 
a 

o 
o 

O 
o 

bC 


g 
a; 

w 

'S 

<13 

a 
a 

o 

T3 

o 

o 

bC 


a 

03 
<X> 

o 

o 
w 

'o 

03 

a 
a 

o 
o 

_5 

"S 
o 

X 


a 

c3 

a; 

Ci 

OJ 
o 

;-< 
01 

a 
a 

o 
o 

01 

a 
cc 

c3 

u 

y, 
W 


a . 

£5 

o — ' 

1^ 
0) 03 

a o 

o c 
a3T3 
cc o 


a 

03 

<o 
o 

01 

is 
'3 

;-, 

a 

o 
o 

01 

c 

o3 

L< 
-M 


Excellent quality French ice cream. 
Low milk solids not fat. Difficult 
to obtain high overrun. 


Extra fine quality French ice cream. 
Low milk solids not fat. Difficult 
to obtain high overrun. 


Cost per 
U.S. Gallon 
Ice Cream 
Containing 
Percentages 
of Overrun 
Indicated 
(Materials 
only) 


to 




% 


"* 
^ 


CO 


05 




CO 
CO 


CO 


Percentage 
Overrun 
Yielding 

Very Satis- 
tory Com- 
mercial 

Ice Cream 


CO 


O 

Oi 




8 


§ 


8 


§ 


s 


00 


Cost per U. S. Gallon 

Mix at 40° F. 
Fat =$0.40 per lb. 
Milk 

S.N.F. = .08 per lb 

Sugar = .06 per lb. 

Gelatin = .50 per lb. 

(Materials only) 


t^ 


(M 


•^ 






LO 


5 

CO 


CM 

00 


i 


o 

•z. 
o 

H 

o 
o 




CO 


CO 


CO 
CO 


CO 
CO 


o 

o 


o 
o 


8 

CO 


CO 


s 




O 

o 

CO 

CO 


O 
O 
•>* 
CO 


CO 


o 
q 

CO 


8 

CO 


8 

CO 


CO 

CO 


GO 

CO 


8 




o 


o 


o 


o 


s 


g 


o 


S 


S 


CO O 


00 


CO 


CO 


8 

CO 


8 

I— 1 


■^ 


o 
o 


-^ 


8 


CO 


s 


o 


c^i 


o 


o 

2 


o 

00 




° 
i^ 


o 

LO 


fa fe^ 


o 
o 

00 


00 


CO 


O 
O 


o 
o 

d 


f>j 


'>i 


CO 


00 




1^1 


- 


!M 


CO 


TtH 


LO 


CO 


r^ 


00 


Oi 



Constituents of Ice; Cream Mix 281 

FUNCTIONS OF THE VARIOUS CONSTITUENTS OF ICE 
CREAM MIX. 

Each constituent of ice cream plays an important part in 
determining the quality of the finished product. Briefly these are 
as follows : 

(1) Fat.— The butter fat determines to a large extent the 
flavor and the palatability of the product. It is rich in vitamines 
and in heat units. The food value is rated largely by the fat 
content. 

(2). Milk Solids Not Fat.— The role played by the milk 
solids not fat is not sufficiently appreciated. Too high milk solids 
not fat may cause sandy ice cream, due to the presence of 
excessive milk sugar. Too low, may render it very difficult to 
obtain satisfactory overrun. The casein and albumin exert the 
largest influence upon the overrun. The milk solids not fat also 
largely influence the nutritive value of the ice cream, due to 
their bone and muscle forming ingredients, present in the salts 
and protein rspectively. These are also rich in water soluble B 
vitamines, and to a lesser extent in the water soluble C. It is 
most important to pay close attention to the content of milk 
solids not fat. 

(3). Sugar. — While the sugar added is obviously for the 
purpose of sweetening the product, and thus increasing its 
palatability, it also possesses high food value. It is the one 
constituent that exerts the most influence upon the freezing point 
of the ice cream. Pure solutions of cane sugar of different con- 
centrations were found to have the following freezing points : — 

10.00 per cent, 30.87° F. ; 12.00 per cent, 30.64° F. ; 14.00 per 
cent, 30.38^ F., and 16.00 per cent, 30.11° F. Based upon the 
water content only, of the ice cream mix, the concentration is 
greatly in excess of these figures. 

(4) Gelatin. — Gelatin is a colloid, and a non-crystallizable 
substance. Its presence in ice cream helps to prevent the crystal- 
loids from separating in the form of large crystals. The prin- 
cipal crystalloids are the milk and cane sugars and the water. 
In ice cream mix of the proper composition the crystallization of 
the two sugars is not likely to be a troublesome factor. Water 
crystals are however always a factor of great importance as in- 
fluencing the smoothness to the taste of the finished product. One 



282 Ice Cream Mixes 

of the chief functions of gelatin in ice cream, is its influence 
upon the water crystals. The gelatin retards the formation of 
water crystals, and helps to produce small water crystals, thus 
making a product more smooth to the taste than otherwise 
possible. 

Relation of Gelatin to Viscosity. — Gelatin has a large influence 
upon the viscosity of ice cream mix. This influence does not 
manifest itself until several hours after the mix has been kept at 
a low temperature. This is owing to the fact that the hydration 
of the gelatin is a slow process, and that many hours are required 
to complete the "setting." This is probably the principal ad- 
vantage gained by aging ice cream mix. In turn the increased 
viscosity produced by aging is a large factor in helping both to 
obtain and to retain the overrun in the ice cream itself. 

The ability of gelatin to increase the viscosity of water solu- 
tions is largely influenced by the quality of the gelatin. Admitted 
that all edible gelatins are made from fresh, clean stock, there 
still exists a wide difference in the viscosity of water solutions 
of equal strength all prepared from edible gelatin of high com- 
mercial quality. It has not been demonstrated if this difference 
is due to the diff'erence in the original raw materials from which 
the gelatin was made, or to the destruction during manufacturing 
processes, or by other causes, of the jellying power, or viscosity 
producing power of the gelatin. 

From a number of samples of edible gelatin, three samples 
were selected that were termed good, medium and poor respec- 
tively. Water solutions of different concentrations were pre- 
pared from each of the samples, and the viscosity of each solution 
was determined, after holding them in ice water for twenty-four 
hours, by means of the Mojonnier-Doolittle viscosimeter as de- 
scribed in Chapter XVII. The results are given in Table 46. 

The results in the following table show plainly the large 
influence of the quality of the gelatin upon viscosity. It explains 
why varying results are obtained in practice, when using equal 
amounts of different gelatins in which the quality varies. 

Relation of Gelatin to Incorporation of Air. — The ability of 
gelatin solutions to incorporate and hold air is best demonstrated 



Gelatin 



283 



by the Frohring gelatin air test. This test is described in 
Chapter XVII. 

TABLE 46. 
Influence of Gelatin Varying in Quality Upon the Viscosity of Water Solutions, 



Percentage of 
gelatin. 


Viscosity expressed in degrees retardation at end 
24 hours 50°F. 


Good quality 
gelatin. 


Medium quality 
gelatin. 


Poor quality 
gelatin. 


Water only. 
No gelatin. 


3.6 


3.6 


3.6 


.10 
.25 

.50 

.60 

.75 

1.00 

1.50 


7.0 

7.0 

8.5 

14.0 

235.0 

Too viscous to de- 
termine viscosity 

Too viscous to de- 
termine viscosity 
by above method. 


6.0 
6.0 
8.0 
9.0 
9.0 

47.0 

Too viscous to de- 
termine viscosity 
by above method. 


6.0 
6.0 
7.0 

7.5 
7.5 

8.0 
43.0 



Table 47 gives the results of several experiments that had 
for their object the determination of the volume of air that can be 
incorporated in different concentrations of gelatin solutions. The 
results show a marked difference between the different samples. 
The ability to hold air increases up to a concentration of about 
60 per cent, after which it decreases with increasing concentration. 
When a concentration ranging from one to two per cent is reached 
the mixture will no longer retain any air. In the sample treated 
with the liquefying organism B. proteus there was a marked 
reduction in the air retaining properties of the mixture. 

Other Influences of Gelatin. — Gelatin constitutes an important 
addition to the food value of ice cream. Bogue^ points out that 
it functions as a true food, but that it is not a complete food 
nor is it the equivalent in food value of the casein and albumin. 
It is incapable of supplying more than one third or one half of the 
nitrogenous matter required in the diet. It helps to preserve the 
nitrogenous constituents of the body; is easily digested, and is 
readilj^ burned in the production of energy. Gelatin functions 
as a protective colloid, and prevents the coagulation of the casein 
in large lumps, thus aiding digestion and assimilation of all the 
constituents of the ice cream even in the case of the very young. 
From a dietary standpoint the presence of good gelatin in ice 
cream is very beneficial. 



284 



Ice Cream Mixes 



TABLE 47. 
Air Whipped Into Various Gelatin Solutions of Different Concentrations. 



Good Gelatin After Having Been 

Treated with Liquefying Organism 

(B Proteus) Incubating for 12 

Hours at 68° F. Cooled in Ice 

Water, and Whipped After One 

Hour 


o 
d 
Q 

.9 2 

§ o 

o 

d 


M 
m.S 

aj'S. 

^.2- 

O 0) 

< 


tC 




?5 


^ 


CO 


00 


05 


lO 


^ 


^ 


CO 






^ 2 

It" 


CO 


CO 


00 




00 


CO 


CO 


CO 


•* 

CO 


CM 

CO 






o 
o 

01 CI — 

S ? 8 


a; 
3 

Q 

1 

.5 d 

^1 

d'.d 

i o 

o 

d 


m 2 

-< 


o 


o 


o 


^ 


rt< 


o 


t^ 


-* 


o 


o 






>>d 


t^ 


o 


CO 


t^ 


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Sources of Supply 285 

SOURCES OF SUPPLY OF INGREDIENTS MAKING UP ICE 
CREAM MIX. 

The ingredients composing ice cream mix are obtainable from 
a variety of different sources. The sources of supply of each 
ingredient are as follows : — 

(1). Fat. — This is present in all dairy products used for 
making ice cream. These include whole milk, skim-milk, cream, 
butter, sweetened condensed milk both whole and skim, plain 
bulk condensed milk, both whole and skim, evaporated milk and 
whole and skim-milk powders. Obviously in the above products 
that have been skimmed the percentage of fat is small, but in 
nearly all cases enough still remains to be taken into account. 

(2). Milk Solids Not Fat.— The sources of supply for M. S. 
N. F. are the same as in the case of fat. The selection of 
material to use is governed by local conditions, market prices, 
and quality available. If the materials used are of the proper 
quality, and are properly handled, the M. S. N. F. from the 
several sources mentioned will yield equally satisfactory ice 
cream. Products in which the milk sugar has crystallized out, 
should be so handled that the milk sugar will all pass into solu- 
tion before freezing the mix. If this is not done, sandy ice cream 
is very likely to result. 

(3). Sugar. — Either cane or beet sugar, both known as 
sucrose can be used to equally good advantage. When sucrose is 
not available, malt sugar, or corn sugar may be substituted to the 
extent of about 25 per cent to 40 per cent of the normal sugar 
or sucrose requirements. 

The common belief that the sweetening power of sucrose can 
be increased by inverting it by means of a weak acid solution has 
been discredited by the researches of Sale and Skimmer.* "When 
342,236 (molecular weight) units of sucrose or ordinary sugar 
are inverted, 180.126 units of dextrose and 180.126 units of levu- 
lose are obtained theoretically. The mixture of dextrose and 
levulose is known as "invert sugar." Their experiments show 
"that if sucrose is assigned sweetening value of 100, the sweet- 
ening value of invert sugar is only 85. Since 100 units of sucrose 
by inversion become 105 units of invert sugar the net loss in 



286 Ice Cream Mixes 

sweetening power by the inversion of 100 units of sucrose is 
about 11 units." 

According to previous experiments in the same laboratory, 
and also according to the investigations of Paul upon the sweet- 
ening power of lactose cited by the above authors the comparisons 
of the relative sweetening qualities of various common sugars are 
as follows: Sucrose=100, dextrose=50; levulose=150; maltose 
=60; and lactose=28. 

(4) Gelatin. — Only gelatin prepared especially for food pur- 
poses should be used, and this should be free from all injurious 
chemicals. According to Cromley,''' ''a good gelatin is one that 
solidifies in the shortest space of time ; has a low percentage of 
ash, a clean inoffensive odor ; makes a clear solution, and is with- 
out chemical or physical impurities." 

The water content of the gelatin should be determined as this 
will influence its commercial value. The usual range is between 
ten and fifteen per cent. 

(5) Miscellaneous Products. — Starch and eggs are sometimes 
used as fillers. These perceptibly increase the total solids of the 
mix. Their use is limited to special ice creams. It is products of 
this kind that make ice cream stand up in the dish after serving. 
Gum tragacanth is frequently substituted for gelatin, and func- 
tions the same as gelatin. Several commercial products commonly 
kno"wm by the general term "ice cream improvers" are in com- 
mon use. These consist of rennet or pepsin mixed with certain 
powders such as milk sugar. These products react upon the 
casein in the mix, causing an increase in the viscosity. They 
need to be used with care, and their action should be fully under- 
stood. In addition to the above products there is a large quan- 
tity of fruits and flavors used in making ice cream. The compo- 
sition of a few of the most important of these substances to- 
gether with a brief description of each is given in Table 48. 
The list includes one sherbet formula that will yield a fine product 
for use in connection with ice cream upon the Mojonnier Ice 
Cream Packaging Machine wherein the ice cream is packaged 
directly from the freezer into the carton, while still in the plastic 
condition, and then in turn hardened in the carton. 



I^LAVORS, Fruits and Nuts 



287 



TABLE 48. 

Name and Description of Flavors, Fruits and Nuts Used in Ice Cream, 

Also Sherbet Base. 



NAME AND DESCRIPTION OF 
PRODUCTS 



Ether 
Soluble 
Constit- 
uents 



Cane 

Sugar 



Fruit 
Sugars 



Total 
Solids 



Cocoa Syrup ^ and ^. Formula^: 2 lbs. 
sugar; 13^ lbs. cocoa; 1 quart water, and 
yi oz. cirmamon extract. Thoroughly 
mix the cocoa and sugar. Add the water; 
heat to 175° F. and hold for 20 minutes 
with constant stirring. Do not allow 
to boil. When cool add J^oz. cimiamon 
extract. The above is sufficient for 5 
gallons of ice cream mix, or 10 gallons of 
ice cream 

Cocoa Syrup''. Formula h 1 lb. sugar 
M lb. cocoa, and 1 quart water. Prepare 
and use the same as above 

Cocoa Syrup^. Formula^: 2 lbs. sugar; 
1 lb. cocoa, and 1 quart of water. Pre- 
pare and use the same as above 

Chocolate Syrup^ Formula: 1 lb. bit- 
ter chocolate; 1 lb. sugar; 1 quart water, 
and \i oz. cinnamon extract. Heat one 
pint of water to boiling; add the shredded 
chocolate, and stir imtil a pasty con- 
sistency is reached. Now add second 
pint of water, and heat until it simmers, 
stirring constantly. When cool add Y2 
oz. cinnamon. The above makes enough 
syrup for 10 gallons of ice cream 

CarameP 

Sherbet Base^, Recommended for use 
upon Mojonnier Ice Cream Packaging 
Machine. Formula: 30 lbs. sugar; 18 
ozs. of a 50 per cent solution of citric acid; 
9 ozs. gelatin; 10 ozs. color; 2 gals, con 
densed skim-milk containing 25.5 per cent 
total solids; and 63^ gallons water. In 
case condensed skim-milk is not avail- 
able, equally satisfactory results are 
obtained by making the following sub- 
stitutions in the above formula: — (1) 4 
gallons of whole milk and 43^ gallons of 
water, or (2) 5 gallons of skim-milk and 3 
gallons of water. The above quantity 
makes up 10 gallons which should be 
frozen to yield 16 gallons of product, or 60 
per cent of overrun. The above can be 
used as a base to which any desired flavor 
can be added. When fresh fruits are 
used omit enough water to bring the total 
volume up to 10 gallons. Mix all above 
products together cold, adding the citric 
acid just before freezing 



Per 

Cent 



Per 
Cent 



Per 

Cent 



Per 

Cent 



7.16 



5.27 



3.32 



35.70 



26.26 



39.63 



61.50 
45.18 
58.65 



14.64 
5.22 



24 48 
26.10 



52.73 
82.07 



.30 



28.75 



34.15 



288 



Ice Cream Mixes 
TABLE 48 (Continued). 



NAME AND DESCRIPTION OF 
PRODUCTS 



Ether 
Soluble 
Constit- 
uents 



Cane 

Sugar 



Fruit 
Sugars 



Total 
Solids 



Apples^ average 29 analyses 

Apricots*, average 11 analyses 

Bananas*, average 6 analyses 

Blackberries*, average 9 analyses 

Cherries*, edible portion, average 16 analy- 



Cherries^, maraschino 

Cranberries*, average 3 analyses 

Currants*, average 1 analysis 

Figs*, average 28 analyses 

Figs*, dried average 3 analyses 

Grapes*, edible portion, average 5 analyses 

Grapes*, dried, average 1 analysis 

Huckleberries*, average 1 analysis 

Lemons*, edible portion, average 4 analyses 

Muskmelons*, edible portion, average 1 
analysis 

Oranges*, edible portion, average 23 analy- 
ses 

Peaches*, edible portion, average 2 analyses 

Peaches'', canned 

Pears'', edible portion, average 2 analyses . . 

Pineapple*, edible portion, average 1 
analysis 

Pineapple', preserve, red, average 1 analy- 
sis 



Per 

Cent 
.50 
.50 
.60 

1.00 

.80 
.26 
.60 



Per 

Cent 



Per 

Cent 



.30 
.60 
.60 
.60 
.70 



Pineapple^ preserve, white, average 1 
analysis 

Prunes*, edible portion, average 20 analyses 

Raspberries*, black, average 3 analyses. . 

Strawberries*, edible portion, average 22 
analyses 

Strawberry Preserve" 

Strawberries, cold packed' 

Bitter Chocolate' 

Zanzibar Cocoa' 

Vanilla Extract' 

Gelatin' 

English Walnuts*, average 2 analyses — 

English Walnuts', average 2 analyses 

Pecans*, edible portion 

Pecans', edible portion 

Sajo Starch*, as purchased 

Eggs*, hens, edible portion, average 19 
analyses 

Eggs, hens, white 

Eggs, hens, yolk 



.20 
.10 
.05 
.50 

.30 

.16 

.23 



1.00 

.60 

.41 

.23 

54.77 

25.38 



63.40 
64.22 
70.50 

64.68 



12.00. 

.20 

33.30 



.68 



19.72 



19.73 
18.18 



33.14 
41.40 



31.65 



17.32 



Per 
Cent 
15.40 
15.00 
24.70 
13.70 

19.10 
33.08 
11.10 
15.00 
20.90 
81.20 
22.60 
65.20 
18.10 
10.70 

10.50 

13.10 

10.60 

9.35 

15.60 

10.70 

60.34 

58.29 
24.40 
15.90 

9.60 
57.51 
24.02 
98.61 
96.01 

9.07 
86.08 
97.50 
96.31 
97.30 
98.35 
87.80 

26.80 
13.80 
50.50 



Defects 289 

THE RELATION OF COMPOSITION TO ICE CREAM DEFECTS. 

Many defects in ice cream attributed to other causes are due 
to defects in composition. 

(1) Fat. — Too low a content of fat sacrifices both the pala- 
tability and the food value of the ice cream. Too high fat pro- 
duces an ice cream that is difficult to assimilate, because of its 
large content of heat units. This is more objectionable in sum- 
mer than in winter. The outside ranges for good commercial 
ice cream are from 8.00 per cent to 14.00 per cent of fat. Above 
14.00 per cent the ice cream enters a special class commonly 
called French ice cream. 

(2) Milk Solids Not Fat. — Improper control of the milk 
solids not fat is responsible for many ice cream defects. The 
ability both to obtain and retain overrun in ice cream depends 
largely upon its content of casein and albumin. The minimum 
should be not under 4.00 per cent of total protein. The reader 
is referred to Chapter XV for further discussion of this problem, 

Sandy Ice Cream, Cause and Prevention. — The content of milk 
solids not fat has a direct bearing upon the defect commonly 
known by the term "sandy ice cream," A careful investigation 
of this subject was made by one of the authors^'' and several as- 
sistants. In the course of these investigations several papers 
have appeared upon this subject namely : by Bothell/^-^^ Zoller 
and Williams ^^ and Williams". 

Sandiness in ice cream is readily detected by the consumer. 
It ranks as the worst of all the common ice cream defects, and 
it is responsible for large losses among ice cream manufacturers. 
Its occurrence is well night universal. It is caused by the milk 
sugar which is only about one fourth as sweet as sucrose and 
comparatively insoluble in the mix, particularly at the reduced 
temperatures used in making and holding ice cream. 

Milk sugar crystallizes in keystone shaped crystals, that are 
described by P. Groth^^ as : 

Monoclinic-sphenoidal. Cleavage in three directions nearly at 
right angles. Refractive indices, a = 1.517; y8=:1.542;=Y 1.550 
+0.005 Bx^ c=10°, a=99^ 2E=83>4°. Sign—, sp. gr. 1.525 
—1.534. 



290 Ice Cream Mixes 

The sharp corners of the milk sugar crystals stick to the 
tongue giving the sensation of eating sand, from which the defect 
derives its name. The name is, however, slightly a misnomer, 
since milk sugar dissolves slowly in unsaturated water solutions 
while sand is insoluble, and the crystals crumble fairly readily 
under the pressure of the tongue or the teeth, which would not 
be true in the case of sand. 

Conditions That May Cause Sandy Ice Cream. — There are two 
general conditions under which sandy ice cream can be pro- 
duced. 

(1) By using products containing crystallized milk sugar re- 
gardless of the composition of the mix, when the mix is not pas- 
teurized. Such products include sweetened condensed milk, both 
whole and skim, and sometimes also plain bulk condensed milk 
both whole and skim. To produce sandy ice cream under these 
conditions, the ingredients composing the mix must be mixed 
cold, and frozen before the milk sugar has had sufficient time to 
go into solution. If the mix is standardized to the proper com- 
position and it is then pasteurized before freezing, there can be 
no danger of producing sandy ice cream when using products con- 
taining crystallized milk sugar. 

When sandiness is due to the use of products containing 
crystallized milk sugar, the sandy condition can be detected as 
soon as the ice cream is drawn from the freezer. If the mix was 
of the proper "composition, the sandiness will not increase while 
hardening, since only the milk sugar that was actually crystal- 
lized before freezing will appear as sand. This cannot go into 
solution after freezing. 

(2) By using a mix of improper composition, regardless of 
the products used, and also regardless of whether or not the mix 
has been pasteurized. In this ease, the sandiness will not appear 
until the ice cream has stood in the hardening room long enough 
for the milk sugar to crystallize out. 

Experimental Evidence. — A number of careful experiments 
were conducted, and these are reported herewith. 

(A) Influence of size of crystals and temperature upon the 
solubility of milk sugar crystals. 



Milk Sugar Crystals 



291 



(1) One lot of ice cream mix testing 18.50 per cent milk 
solids not fat and 40.00 per cent total solids was prepared by 
using a smooth sweetened condensed milk containing small milk 
sugar crystals as the source of the milk solids not fat. This was 
heated rapidly with constant agitation, taking 10 minutes to 
reach 140 deg. F. It required one minute to dissolve the milk 
sugar crystals. 

(2) Another lot of ice cream mix was prepared and handled 
the same as above, excepting that in this case, coarse, sweetened 
condensed milk containing large milk sugar crystals was used. 
It required three minutes to dissolve the milk sugar. 

(3) In a third experiment, a 5 per cent mixture of water 
and both fine and coarse milk sugar crystals were prepared. The 
solubility of the two sizes of crystals in water at different tem- 
peratures was carefully noted. The results are given in Table 49. 

TABLE 49. 

Influence of Temperature and of Size of Ciystals Upon Solubility of Milk 

Sugar Crystals. 







Temperature 


Time required 


Sample 


Size of 


of water. 


to dissolve crystals. 


No. 


crystals. 


Deg. F. 


Minutes. 


1 


small 


40 


33.00 


2 


small 


68 


2.50 


3 


small 


140 


.16 


4 


large 


40 


64.00 


5 


large 


68 


14.00 


6 


large 


140 


2.00 



The results of the above experiments show the influence of 
the size of the milk sugar crystals upon the length of time re- 
quired to effect their solution at pasteurizing and other tem- 
peratures — obviously the larger the crystals, the longer the time 
required to dissolve them. 

(B) Influence of Pasteurization — There was prepared one 
lot of ice cream mix testing 12.50 per cent milk solids not fat and 
^4.00 per cent total solids, using cream, skimmilk powder, gelatin, 



292 



Ice Cream Mixes 



sugar and water. The gelatin was dissolved in the added water, 
and the solution cooled before adding to the other ingredients, 
keeping the entire mixture down to about 40° F. 

One half of the above lot was frozen immediately without pas- 
teurizing. The other half was pasteurized at 140 deg, F. for 30 
minutes, cooled and then frozen. Slight sandiness began to ap- 
pear in both lots after being in the hardening room 24 days. 

(2) There was prepared a second lot of ice cream mix test- 
ting 18.50 per cent milk solids not fat and 40.00 per cent total 
solids, using the same ingredients, and proceeding otherwise as 
described under (A). The ice cream from both the pasteurized 
and the unpasteurized portions began to show slight sandiness 
after being in the hardening room 7 days. 

The results of this experiment show that sandiness is not in- 
fluenced by pasteurization when milk solids not fat are obtained 
from milk powder, under the conditions named above. 

Influence of Composition of Mix — Ten bottles of ice cream mix 
of different composition were compounded. The raw materials 
used consisted of pasteurized cream, plain condensed skim-milk, 
sugar and gelatin, all being of high quality. A sample from 
each batch was frozen, and then transferred to a hardening room 
with a temperature of — 5° F. to 5° F. 

The essential facts and results of this experiment are given in 
Table 50. 

TABLE 50. 
Influence of Composition of Mix on Milk Sugar Crystallization. 







COMPOSITION OF 


BATCHES 




No of da.vs in 
hardening room 




No. of 












Extent of 


Mix 


Fat 


M.S.N.F. 


Sugar 


Gelatin 


T. S. 


before sandiness 


sandiness 




Per Cent 


Per Cent 


Per Cent 


Per Cent 


Per Cent 


appeared 




1 


8.00 


11.50 


13.00 


.50 


33.00 


56 


Slight 


2 


8.00 


12.50 


13.00 


.50 


34.00 


27 


Considerable 


3 


8.50 


12.00 


13.00 


.50 


34.00 


27 


Considerable 


4 


9.00 


11.50 


13.00 


.50 


34.00 


36 


Slight 


5 


10.00 


10.50 


14.00 


.50 


35.00 


87 


Slight 


6 


12.00 


8.50 


14.00 


.50 


35.00 


No sandiness at 
end 87 days 


None 


7 


12.00 


9.50 


14.00 


.50 


36.00 


do. 


None 


S 


16.00 


7.60 


14.00 


.50 


38.00 


do. 


None 


9 


18.00 


7.50 


14.00 


.50 


40.00 


do. 


None 


10 


8.00 


18.50 


13.00 


.50 


40.00 


6 


Very heavy 



Ove;rrun 



293 



The results oi this experiment are most significant and prove 
conclusively the importance of the exact control of composition 
upon sandiness, particularly with regards to the milk solids not 
fat. The mix containing 18.50 per cent of milk solids not fat, 
showed sandiness at the end of six days while up to 9.50 per 
cent no sandiness appeared up to 87 days. 

(D) Influence of Amount of Overrun. — One lot of ice cream 
testing 8.00 per cent fat, 18.50 per cent milk solids not fat, 13.00 
per cent sugar, and .50 per cent gelatin making 40.00 per cent 
total solids, was divided into two portions. 

One portion was frozen with as little overrun as possible, 
about 10 per cent, and the other portion with as much as pos- 
sible, about 100 per cent. Sandiness appeared in both lots of ice 
cream after they had been in the hardening room six days. The 
crystals in the lot with low overrun appeared throughout the 
experiment to be somewhat larger, and therefore more noticeable 
to the taste than in the case of of the lot with high overrun. 
The difference was probably due to the greater concentration of 
crystals in a given volume of the frozen product. The amount 
of overrun was not found to be of practical significance as 
affecting sandiness. 

(E) Influence of Miscellaneous Factors Upon Sandiness. The 
results obtained in this experiment indicate that the consistency 
to which the ice cream was frozen, the addition of lactic acid, 

TABLE 51. 
Influence of Miscellaneous Factors. 



Method of handling ice cream. 


Number of days 

in holding room 

before sandiness 

appeared. 


Remarks 


Frozen to hard consistency 


5 


All samples alike 






Frozen to soft consistency 


5 


as regards sandi- 




.3 per cent lactic acid added 


5 


ness. 






.4 per cent lactic acid added 


5 




.6 per cent lactic acid added 


5 
5 




1 per cent pulyerized nuts added .... 





294 



Ice Cream Mixes 



or of pulverized nuts, had no influence upon sandiness. The milk 
sugar crystallized out about equally in all cases. 

(F.) Influence of the Solubility of Milk Sugar. The solu- 
bility of milk sugar has been studied by Dubrunfaut ;^® by C. S. 
Hudson^'; by E. Soillard^^ and by Mack & LiedeP''. Confirma- 
tory tests were made by Liedel in the Research Laboratories of 
Mojonnier Bros. Co. at the temperatures used by the above 
authorities and in addition the solubility was determined at 
temperatures both higher and lower than those reported by other 
authorities. 

Tabulating all of the results reported, we find the solubility 
of milk sugar to range as indicated in Table 3, and Fig. 7, Chap. II. 

The solubility of milk sugar was determined in water con- 
taining various substances, such as varying amounts of lactic 
acid, common salt and lime. The results thus obtained are given 
in Table 52. 

TABLE 52. 
Solubility of Milk Sugar in the Presence of Other Products. 



Compositions of 


Solubility of Milk Sugar in 100 parts at: 


Water Solutions 


41° F. 


50° F. 


59° F. 


70° F. 


84° F. 


.20 per cent lactic acid. . . . 


13.51 


14.80 


17.12 


21.06 


23.80 


.40 per cent lactic acid. . . . 


13.42 


14.63 


17.06 


20.87 


24.72 


.60 per cent lactic acid. . . . 


13.38 


14.42 


17.00 


20.73 


24.60 


1.00 per cent lactic acid. . . . 


13.20 


14.31 


16.95 


20.45 


24.49 


.20 per cent salt (NaCl).. .. 


13.60 


13.77 


17.06 


20.21 


24.85 


.50 per cent salt (NaCl)..., 


13.55 


13.26 


16.71 


20.50 


24.68 


1.00 per cent salt (NaCl).. . . 


13.48 


13.13 


16.90 


20.43 


24.80 


Saturated Lime Water 


13.60 


14.85 


17.60 


20.84 


25.02 


Water only 


13.36 


14.90 


16.78 


19.50 


24.40 



The results given in Table 52 are not entirely consistent, due 
to analytical errors caused by the difficulties involved in making 
double solubility determinations. The differences found are so 
slight as to prove that the solubility of milk sugar in acid, alka- 
line and salt solutions within the limits of the experiment, is the 
same as in water only. 



Milk Sugar CRvsTAts 



295 



In another experiment, the separation of milk sugar from ice 
under different conditions was carefully determined. The water 
solutions were transferred to a hardening room with temperature 
about 0^ F, At the end of ten days the frozen samples were all 
returned to the laboratory, and immediately^ after the ice was 
melted, the water was decanted and the precipitated milk sugar 
was separated and weighed upon a Gooch crucible, in all cases 
where this was possible. The results of this experiment are given 
in Table 53. 

TABLE 53. 

Separation of Milk Sugar from Ice Under the Various Conditions Named. 



Water 

Used 

c. c. 


Grams 
Lactic 
Acid 
Used 


Grams 
Milk 

Sugar 
Used 


Days in 

Hardening 

Room before 

Crystals 
Separated 


Total 

Days in 

Hardening 

Room 


Grams Milk 

Sugar 

Separated 


Remarks 


99.0 


none 


1.00 


5 




not 
determined 




98.0 


u 


2.00 


4 




" 




97.0 


ii 


3.00 


3 




u 




96.0 


« 


4.00 


3 




" 




95.0 


11 


5.00 


2 


10 


.86 




100.0 


" 


10.00 


2 


10 


1.30 




99.8 


.2 


1.00 


5 


10 


none 


Milk sugar 
redissolved 
when ice 
melted. 


99.8 


.2 


5.00 


2 


10 


.85 




99.8 
99.6 


2 

'a 


10.00 
1.00 


2 
5 


10 
10 


1.32 
none 


do 


99.6 
99.4 


.4 
.6 


5.00 
1.00 


2 
5 


10 
10 


.80 
none 


do 


99.4 


.6 


5.00 


2 


10 


.86 





The results given above prove that milk sugar crystallizes 
from ice, when present in amounts as small as one per cent. 
Such crystals are readily detected with the human eye. The 
amount actually crystallized could not be determined accurately 



296 



Ice Cream Mixes 



by the method used, since a considerable part of the milk sugar 
passed back into solution as fast as the ice melted. The quantita- 
tive determinations that were made show that the amount of 
sugar which separated from an acid solution of milk sugar, was 
no larger than in the case of pure water solution. The milk sugar 
which separated from the ice appeared to be more amorphous 
than crystalline. Its water content was not studied. 

The solubility of milk sugar in ice cream mix and in sucrose 
solution formed the basis of a careful study by Travis.^" He 
found the relative final solubility of lactose in different media 
at various temperatures as shown in Table 54. 

TABLE 54. 

Relative Final Solubility of Lactose at Various Temperatures and in Different 
Media According to Travis. 



Media. 


Grams of lactose per 100 
Grams of water at: 




0°C. 


10° C. 


25° C. 


Water (Hudson results) 


12.50 


15.92 


22.8 


Sucrose, 14 per cent solution . . 


8.40 


9.95 


13.25 


Ice cream mix testing 12.00 per 
cent fat; 14.00 per cent su- 
gar; .50 per cent gelatin and 
36.00 per cent total solids . . 


] 

17.50 


24.60 


Not reported 



As the results in Table 54 show, lactose was found by Travis 
to be less soluble in sucrose solutions than in pure water, and 
more soluble in ice cream mix than in pure water. He attributes 
this difference to the possible effect of "some colloid or colloids 
in the ice cream mix," 

In view of the ease with which lactose crystals separate from 
ice even at as low concentrations as one per cent, as shown in 
Table 54, Travis' results offer an explanation as to why its 
separation in the form of sandiness in ice cream is not larger 
than usually encountered. 

Conclusions: — (1). Sandiness in ice cream is caused by the 
milk sugar contained in the mix. The largest single factor caus- 



Sandiness 297 

ing sandiness is an improper content of milk solids not fat. A 
mix containing 18.50 per cent milk of solids not fat developed 
sandiness in the frozen product at the end of six days, while 
all mixes containing 9.50 per cent or less of milk solids not fat, 
did not show any sandiness after the frozen product had been in 
the hardening room 87 days. Ice cream mix containing 12.50 
per cent of milk solids not fat did not show any sandiness until 
the ice cream was 27 days old. It is probably very seldom that 
ice cream is kept for this length of time. A content of 12.50 
per cent of milk solids not fat is equal to about 6.70 per cent of 
milk sugar, or about the limit recommended by Bothell (cited 
above). Ice cream can contain more than the above limit of 
milk solids not fat, but if it goes quickly into consumption there 
will be no complaints from sandy ice cream. 

The next largest single factor causing sandiness is the age of 
the ice cream. The older the ice cream, the more likely is sandi- 
ness to appear. Complaints from sandiness are most liable to 
come from small dealers who move their ice cream slowly, or in 
the case of special flavors that meet with a limited demand. 

(2). Solutions containing as little as one per cent of milk 
sugar contain crystallized milk sugar after being in the hardening 
room for eight days or less. 

The increased solubility of milk sugar in ice cream mix as 
reported by Travis may account for the fact that larger quanti- 
ties of milk sugar can be safely used without causing sandiness in 
ice cream, over the amount that would theoretically produce 
sandiness. 

The greater the concentration of milk sugar in ice cream, the 
sooner will the crystals become apparent to the taste. In all 
cases the milk sugar crystals will be visible under the microscope, 
before they become apparent to the taste. The size of the milk 
sugar crystals was found under the microscope to vary con- 
siderably. The larger the crystals obviously the more apparent 
to the taste is the sandiness of the ice cream. 

(3). Pasteurization of the mix, particularly where the milk 
products used contain crystallized milk sugar, helps to retard 
sandiness in the case of a mix containing an excess of milk sugar, 
over that suggested by good practice, and it helps to prevent it 
entirely when the mix is of the right composition. A mix com- 



298 Ice; Cream Mixes 

pounded from milk products containing crystallized milk sugar, 
if not pasteurized, will show up sandiness immediately after 
freezing regardless of the composition of the mix — the larger 
the milk sugar crystals in the raw products, the more apparent 
will be the sandiness in the finished product. 

(4). Sugar.— Too low sugar content gives a product that is 
insufficiently sweet ; too much sugar, one that is excessively sweet. 
A product containing excessive sugar has a low freezing point, 
and consequently is more difficult to keep in good condition in 
the dealers' cabinets. The best range of sugar is from 13.00 to 
14.00 per cent. Also the more sugar that is used, the more 
difficult it is to obtain the desired overrun. Further discussion 
of this subject will be made under Chapter XV. 

(5). Gelatin. — One of the most important physical properties 
of ice cream is its texture, or in other words, its smoothness to 
the taste. This is caused principally by the size of the water 
crj^stal — obviously small water crystals producing an ice cream 
that is smooth to the taste and large water crystals one coarse to 
the taste. Several factors influence the size of the water crystals, 
but probably no single factor has greater influence than the 
gelatin content of the ice cream. 

A careful experiment was made to determine the proper limits 
of gelatin to use. A quantity of ice cream mix was prepared test- 
ing 8.00 per cent fat, 12.50 per cent milk solids not fat, 13.00 per 
cent sugar, making 33.50 per cent total solids. This was divided 
into different lots and these in turn handled as shown in Table 55. 
The various lots were all frozen quickly, and then transferred to 
a hardening room with temperature around 0^ F., and kept there- 
in for the time indicated in Table 55. 

The results given in the following table prove the value of 
adding gelatin to ice cream. The best results were obtained by 
adding .50 per cent gelatin to the mix before pasteurizing. Gela- 
tin usually contains only about 83.00 per cent of total solids. 
The addition of .60 per cent of gelatin will provide about .50 per 
cent of the water free substance. An excess of gelatin produces 
an ice cream that does not melt readily upon the tongue, besides 
it unnecessarily increases the cost of the ice cream. 

The possible influence, if any, that gelatin may exert upon 
the crystallization of the milk sugar is not known at this time. 



GeIvAtin and Water 



299 



It would be theoretically possible for the gelatin to retard the 
crystallization of the milk sugar, as well as the crystallization of 
the water. 

(6.) Water. — The water content of ice cream influences both 
its chemical and physical properties. Excessive water impairs the 
food value of the ice cream. The maximum limit under good 
practice is 67.00 per cent water, corresponding to 33.00 per cent 
total solids. The minimum- limit is 60.00 per cent of water cor- 
responding to 40.00 per cent total solids. 

TABLE 55. 
Influence of Gelatin Upon the Physical Properties of Ice Cream. 



How Mix 
was Treated 


How Gela- 
tin was 
Added 


Percentage 
Gelatin 
Added 


Condition of 

Ice Cream 

one day after 

Freezing 


Condition of 

Ice Cream 

eight days after 

Freezing 


Numerical Quali'.y 
Rank of various 

lots of Ice 

Cream at end of 

Eight Days 


Pasteurized at 
140° F. held 
for 4 days at 
40° F. 


Before pas- 
teurizing 


.50 


Smooth 


Smooth 


1 


Not pasteurized 
held for 4 
days at 40°F. 


After hold- 
ing 4 days. 
Just before 
freezing 


none 


Coarse, grainy 


Coarse, not fit 
for sale 


6 


" 


" 


.20 


Coarse 


Coarse 


5 


" 


" 


.40 


Slight grain 


Coarse 


4 


" 


" 


.50 


Smooth 


Smooth 


2 


" 


" 


.60 


Smooth 


Smooth 


2 






.70 


Smooth but Ice 
Cream did not 
melt readily 


Smooth but 
slimy 


3 






1.00 


Smooth|but Ice 
Cream.did not 
melt 


Slimy. Not fit 
for sale 


6 



The influence of the water content upon the physical property 
of ice cream is usually not fully understood nor fully appreciated. 
It is the size of the water crystals that determines the texture 
or smoothness of the product. 

The best work reported to date upon this subject is that by 
Hall.-^ Scale showing relative diameter of smooth and coarse 
textured crystals is reproduced under Fig 79. Hall found that, 
"Cream which left the freezer having 10 per cent of its water 
frozen, upon reaching 20 degrees had 42 per cent of its water 
frozen ; at 10 degrees, 55 per cent, and at minus 5 degrees 67 per 



300 



Ice Cream Mixes 



cent. It is doubtful if over 70 per cent of the water in ice cream 
is ever frozen. No matter at what temperature the ice cream 
may leave the freezer, the continued freezing in the hardening 
room follows the law as represented by the curve under Fig. 80. 



Tig. 79. Scale Showing- Relative Diameters of Smooth and Coarse Texture 

Crystals. 



30 



25 



20 



^ 15 



'—■n 

, ^- 

. ^^t" 

— ». — X 

j^_> ^^ 

+ \ 



_s 

S 10 15 20 25 30 35 40 45 50 55 60 65 70 75 

Per Cent of Crystals Fro-'"" 
Pig". 80. per Cent of Prozen Crystals. 

Hall applies the same principles of crystallization to freezing 
the water content of ice cream mix as are described in this book 
for controlling the milk sugar crystals in sweetened condensed 
milk. Namely, "slowly formed crystals are large, and quickly 
formed crystals are small." He recommends placing the ice 
cream as it comes from the freezers in a hardening room of very 
low temperature, say — 15° F. Then after the ice cream has 
hardened, transferring it to the regular hardening room with 
temperature of about 5° F. He further points out the fact already 
recognized by many manufacturers that "small cans on account 
of being quickly frozen, usually contain smoother texture cream 
than large cans." 



Standardization 301 

THE STANDARDIZATION OF ICE CREAM MIX. 

Definition and Advantages.— The standardization of ice cream 
in a broad sense, has reference to the control of the fat, milk 
solids not fat, sugar, flavor, color, and of the overrun in the 
finished product. This chapter will treat more especially of the 
chemical control of the ingredients making up the mix, while 
Chapter XV treats of the control of the overrun. In no other 
branch of the dairy industry can such important results be 
obtained by complete standardization as in the ice cream industry. 
The three main advantages to be gained are (1) turning out a 
product of uniform composition; (2) manufacturing with the 
greatest possible .degree of economy; and (3) avoiding the 
marketing of a product under the legal or trade standards. 

Steps Involved. — The steps involved in standardizing ice 
cream mix are as follows: (1). Ascertaining the pounds, and the 
fat and T. S. tests of all materials on hand or available that are 
to be used for making up the batch. If the tests of the available 
materials are made at the plant, all of the precautions usually 
required in collecting the samples must be observed. Accuracy 
of the tests can be of little value unless the samples upon which 
the tests are based are exactly representative of the entire lot of 
material in question. 

(2). As a rule, it is not necessary for standardizing purposes 
to test with the Mojonnier Tester all the materials available for 
making up the batch. However, it is recommended that all ma 
terials purchased be tested, as that is the only satisfactory method 
of checking purchases, and at the same time this affords a large 
help in compounding the mixes. Also, if the exact test of the 
materials available for standardizing is known it will make for 
greater accuracy in the final standardization. 

(3). Determining the pounds that the batch is to contain, 
and the percentage of fat, M. S. N. F., sugar and other ingredients, 
that the batch is to contain after standardizing. It is usually 
necessary to manufacture not more than two different standard- 
ized products. The standards to be followed are sometimes set 
by State or Federal authorities, and again individual manu- 
facturers may elect to set special standards of their own — the 
same being higher in fat or T. S., or both, than the legal standards 
that might otherwise govern. 



302 Ice Cream Mixes 

(4). Calculating the pounds of fat and T. S. that the batch 
should contain, and with this as a basis, determining the pounds 
of various materials required to make up the batch. 

(5). After the materials for the batch have all been very 
thoroughly mixed, a sample is taken to be tested for both fat and 
T. S., also record is made of the total pounds of each material 
composing the batch. Great care is necessary to get a sample 
that is representative of the entire batch. 

(6). Computing the material required for standardizing the 
batch to the desired standard upon the basis of the weights and 
tests as found under (5). 

GENERAL METHODS OF COMPOUNDING ICE CREAM MIX. 

Several methods are available for compounding and standard- 
izing ice cream mix, as follows : 

(A). By Using a Vacuum Pan. — This is commonly known as 
the Mojonnier method, and is covered by the pending process 
patents of one of the authors and his brother.-- 

Where this method is possible, it has numerous advantages 
over all other methods. The whole milk is sampled and tested 
for fat .and T. S., and the necessary fat in the form of cream or 
butter, and the necessary sugar and gelatin, are added to the milk 
in the hot wells. The batch is then condensed to the point 
desired. After condensing, the batch is weighed, homogenized, 
cooled, tested for fat and T. S. and standardized to the point 
desired. Under some conditions, it may be desirable to condense 
the product considerably in excess of the concentration desired, 
and to dilute it back with water to the proper concentration just 
before freezing. Mix, so prepared, can be stored for a considerable 
time, and shipped considerable distances. 

Peterson and Tracy-'' made a study of ice cream mix prepared 
in a vacuum pan. Their findings confirmed the foregoing state- 
ments. They also made a bacteriological study of mix prepared 
as above, and of ice cream produced from it. The number of 
bacteria found by them in the different stages of manufacture are 
given in Table 56. 



Prepared in Vacuum Pan 



303 



TABLE 56. 

Number of Bacteria per cc. in Ice Cream Mix Prepared in a Vacuum Pan at 
Different Stages of Manufacture. 



Before heating 
in hot wells. 


Direct from 
vacuum pan. 


Direct from 
homogenizer. 


After addition 
of gelatin. 


In the frozen 
ice cream. 


9,600,000 


800 


1,400 


1,450 


2,600 


2,260,000 


20,000 


26,200 


26,250 


31,000 



The best practice is to add the gelatin to the hot wells before 
heating the milk, rather than to the mix after condensing. This 
will help to reduce the bacteria count. 

Mix prepared under vacuum was found to have very excellent 
keeping qualities as found by the results indicated in Table 57. 



TABLE 57. 

Keeping Qualities of Ice Cream Mix Prepared Under Vacuum and Stored at 

32° to 35°F. 



Day in storage. 


Bacteria per cc. 


Condition of mix. 





1,400 


Very good 





1.700 


Very good 


14 


762,000 


Good 


23 


42.210.000 


Fair 


32 


188,500.000 


Fair (frozen into ice 
cream) 



The results in Table 57 show both the low content of bac- 
teria in mix made as described above, and the excellent keeping 
qualities of the same. Handling operations after condensing, if 
care is taken, do not appreciably increase the bacteria count. 
The mix stored at the temperatures named were of excellent keep- 
ing quality, and remained in good condition up to two weeks. 

The specific gravity of ice cream mixes of nine different com- 
positions, and at various temperatures, are indicated upon the 



304 



Ice Cream Mixes 



chart under Fig. 81. This can be used as the basis for arriving 
at the proper striking point, when finishing the batch at the pan. 

Key to Fig. 81. 



Cujve 


1 


2 


3 


4 


5 


6 


7 


8 


9 


Fat 


8.00 


8.00 


8.50 


9.00 


10.00 


12.00 


12.00 


16.00 


18.00 






T. S 


33.00 


34.00 


34.00 


34.00 


35.00 


35.00 


36.00 


38.00 


40.00 


Sugar 


13.00 


13.00 


13.00 


13.00 


13.00 


13.00 


13.00 


13.00 


13.00 


Gelatin 


.50 


.50 


.50 


.50 


.50 


.50 


.50 


.50 


.50 




SPECIFIC GRA VJTY IN DEGREES BAUME 



rig". 81. Specific Gravity of Nine Different Compositions of Ice Cream Mix 
at Various Temperatures. 

This chapter contains elsewhere methods of calculation recom- 
mended to cover problems of this kind. 



Successive Steps 305 

(B). By mixing condensed products of various kinds. A large 
variety of combinations are possible, and usually if the proper 
methods of calculation are used, such dairy products of the prop- 
er quality, that may be available, can be mixed together and made 
to yield a satisfactory quality of mix. One extreme example 
would be skim-milk and cream; another v^ould be skim-milk 
powder and butter. Problems involving these various combina- 
tions will be found elsewhere in this chapter. 

SUCCCESSIVE STEPS INVOLVED IN STANDARDIZING ICE 

CREAM MIX. 

Unless the mix is compounded at the vacuum pan, two meth- 
ods of standardizing are possible as follows: (1) Ascertain the 
exact fat and T. S. tests of all products available, and upon the 
basis of these tests mix the same in the right proportion to obtain 
a product of the test desired. This method is not recommended, 
as it involves considerable work not required by the method im- 
mediately following. It is well, however, to test all products pur- 
chased for fat and T. S. to determine if they compl^y with the 
purchase specifications. 

(2). Compound the mix upon the basis of the approximate 
tests of the materials on hand. Test the mixture for fat and 
T. S., using the Mojonnier Tester. 

(3). Calculate by methods that follow in this chapter, the 
materials that will be required to standardize the batch to the 
proper content of fat, M. S. N. F. and sugar. 

How to Sample, Test and Weigh the Batch. Follow method 
of sampling recommended under Chapter VI. Use the Mojonnier 
Tester for making all fat and T. S. determinations. "Where pos- 
sible, obtain directly the weight of the batch. If impossible to 
weigh the batch, obtain the total gallonage, and calculate the 
pounds from the figures given in Table 58. Use the Green Gauge 
instead of a scale to ascertain the total pounds of mix in the 
holding tank. 

Order of Operations in Standardizing Ice Cream Mix: (1). 

Test both for fat and T. S. as far in advance as possible all prod- 
ucts that are to be used for standardizing. 



306 



Ice Cream Mixes 



TABLE 58. 

Approximate Weight per Gallon of Water and of Various Dairy Products. 
Temperature About 68° F. 



Name of Product 


Per- 
centage 
Fat 


Percent- 
age Total 
Solids 


Pounds in 

One U. S. 

Gallon 


Name of Product 


Per- 
centage 
Fat 


Percent- 
age Total 
Solids 


Pounds in 

One U. S. 

Gallon 


Water 






8.34 




30.00 


36.24 


8 35 










.20 


8.80 


8.64 




35.00 


40.79 


8 31 








Whole Milk 


3.00 


11.40 


8.59 


Cream 


40.00 


45.35 


8.38 


Whole Milk 


3.50 


11.60 


8.60 


Ice Cream Mix. . . . 


8.00 


34.00 


9.16 


Whole Milk 


4.00 


12.30 


8.61 


Plain condensed 
skim-milk 


1.00 


26.00 


9.18 


Whole milk 


5.00 


13.00 


8.62 


Plain condensed 
whole milk 


8.00 


30.00 


9.05 


Mixed milk and 
cream 


10.00 


18.02 


8.54 


Evaporated milk.. . 


8.00 


26.15 


8.90 


Mixed milk and 


15.00 


22.57 


8.47 


Evaporated milk.. . 


7.80 


25.50 


8.88 


eream 


Sweetened con- 
densed skim-milk 


1.00 


70.00 




Cream 


20.00 


27.13 


8.43 
8.39 


11.16 




Sweetened con- 
densed whole milk 


s.oo 


73.00 




Cream 


25.00 


31.68 


10.90 



(2). About half an hour before the sample from the batch is 
ready, do everything necessary to begin making fat and T. S. 
tests. 

(3). Keep the fat and T. S. dishes in the respective ovens 
for 5 minutes, under proper heat and with the vacuum on. 

(4). Transfer the dishes from the ovens to the coolers. Keep 
the water circulating. Weigh the T. S. dish with cover at the 
end of 5 minutes, and the fat dish alone at the end of 7 minutes. 
Record the weights and numbers upon the laboratory report Fig. 
53, Chap. VII. Replace the dishes in the coolers. 

(5). Mix the sample thoroughly. 

(6). Fill the one gram pipette to the mark, and transfer the 
milk to the previously weighed dish, and weigh the dish with 
milk immediately. Fill the 5 gram pipette to the mark, and by 
means of the weighing cross, weigh about 5 grams into the fat 
extraction flask. ^ ^^IIMI 

(7). Prepare the sample for the T. S. and the fat ovens re- 
spectively; heat in the ovens, cool in the coolers, and weigh an 
directed. 



Successive Steps 



307 



(8). Calculate the percentages of fat and T. S. and transfer 
the results to the ice cream mix and cost report, Fig. 82. 

(9). Calculate the pounds of material necessary to add, select- 
ing and using the rule that may apply. 





giaM.P, 31 

D«le 




ICE CREAM 

Plane 


MIX AND 


COST 


REPORT 

Batct 










Libo-ion i<.» P.>i»i> 


c... 




't™." 


■■.,.<. 


[HHad itUca 




... 


iS 


••■^ 




.... 


T»^.-. 










C.-» 1 








1 














C.«. 










1 
























1 
























1 










1 












1 
























1 
























1 














Sk.mUU^,»^« 




























































1 


1 


1 








1 














1 
























1 
























1 
























1 


Nui. 






















1 
























1 
























1 






















^^ 
















'•""- 1 "•"•"" 


"" 


*"-■ 


..■Sri. c™ „.,... .,.„.„.„ 










LabomcT >'•■• P*' ».•• 




Added to standardize 




•■' 1 ""•• 


,i- 


— 


^°s;.r;."" 


.'■.•n";u,|,.';.ri.| '.r.i' 


^;:^:^' \ '^s.t 




1 


















I 






















j 























1 








T,.l ,.., .f ...,„ „,. 


— i= 






O.llo« ... .<]... ,. ...„.„„. 






Gdl«.. l« c».n a»l. 




Cnnd ....1 P.-..4. &I ..u,. .!■ 




Cr«>d .GUI (.tlon. .1 oil. 




C„. „, cs.. .r. 




C,.« ,.,.1 ., ..11.™ K. „,„ ^, 




C... p.. nil." .« cr«« l,„I.M 




0..m,n «.., ob..l«tf 








A..ru. o«r™» •„■, 








C... p„ nllo. on«..l «.<■ 



























































Tig". 82. Ice Cream Mix and Cost Report. 



(10). Add the standardizing materials to the batch. Mix 
thoroughly. Make a retest for fat and T. S. Complete all pos- 
sible or necessary calculations upon the above report blank. 

The use of this blank reduces the possibilities of errors to a 
minimum; provides a means of computing the cost per gallon of 
the mix, and gives a clear history of every batch of ice cream 
made. Any troubles that may arise can be more readily traced 
if a record of this kind is kept. 



308 



Ice Cream Mixes 



Standardizing and Holding Tanks for Ice Cream Mix. Several 
different designs of suitable tanks are available for the mixing and 
holding of ice cream mix. In small plants the same tank can be 
used as a batch mixer, pasteurizer, cooler and holder. Figs, 83, 




Tig. 83. Ice Cream Batch Mixer. 

Courtesy Creamery Package Mfg. Co. 



84 and 85 illustrate tinned copper tanks of this kind. Figs. 86 
and 88 illustrate glass enamelled batch mixers, and Fig. 87 a glass 
enamelled standardizing and holding tank. The size of tank to 




Fig-. 84. Ice Cream Batch Mixer. 
Courtesy J. G. Cherry Co. 



use is governed by the quantity of the output. Where the out- 
put so warrants, the larger the tanks used, tiie fewer the stand- 



Batch Mixers 



309 



ardizations that are necessary, and the more exact the control 
that can be maintained over the finished product. 




Fig'. 85. Ice Cream Batch Mixer. 

Courtesy Davis-Watkins Dairymen's Mfg. Co. 




Pig". 86. Ice Cream Batch Mixer. Pig". 87. Ice Cream Holding' Tank. 

Courtesy The Pfaudler Co. 



310 



Ice Cream Mixes 



Kinds of Problems Encountered in Standardizing Ice Cream 
Mix. Numerous methods have been suggested and used for 
standardizing ice cream mix, but usually the attempt has been 




Fig-. 88. Ice Cream Batch Mixer. 

Courtesy Jensen Creamery Machinery Co. 



to standardize the fat only, paying but comparatively little at- 
tention to the solids other than the fat. In the methods which 
follow, the fat, M. S. N. F. and the sugar are taken into con- 
sideration, and if these methods are used as recommended, all 
can be standardized with equal accuracy. Several different com- 
binations of results are possible, all requiring different calcula- 
tions as follows : 

(1). Fat Under, and T. S. Over the Standard Desired. The 

same method of calculations can be used when both the fat and 
the T. S. are over the standard desired, but with the fat in a 



Key TO Factors 311 

lower ratio than the T. S. This is covered by problems 29 and 
30. 

(2). Both the Fat and T. S. Are Under the Standard Desired. 
Three methods of calculations are given for this combination. This 
is covered by problems 31, 32 and 33, 

(3). Fat Over, and T. S. Under the Standard Desired. The 
same method of calculation can be used when both the fat and 
the T. S. are over the standard desired, but with the fat in a 
higher ratio than the T. S. This is covered by problems 34 and 
35. 

(4). Both the Fat and the T. S. Over the Standard Desired, 

and in the proper ratio one to another, making it necessary to 
add sugar and water only. This is covered by problem 36. 

The above problems are solved in this chapter both by rules 
and formulas, and also by examples under each rule and formula. 

KEY TO FACTORS IN FORMULAS FOR STANDARDIZING. 

ICE CREAM MIX 

A = The percentage of fat desired in mix. 

A^ = The percentage of fat short. 

B = The percentage of M. S. N. F. desired in mix. 

B^ = The percentage of water-free gelatin desired in the 
mix. 

C = The percentage of fat in the cream. 

C^ = The percentage of fat in the condensed milk. 

D = The percentage of M. S. N. F. in the cream. 

D^ = The percentage of M. S. N. F. in the whole milk. 

E = The percentage of fat in cream available for standard- 
izing. 

E^ = The percentage of fat in butter. 

E- = The percentage of fat in the whole milk. 

F = The percentage of fat in the ice cream mix before 
standardizing. 

F^ =: The percentage of fat in the condensed whole milk. 

F^ r= The percentage of fat in the whole milk. 

F^ = The percentage of M. S. N. F. in the condensed whole 
milk. 

G z= The pounds of M. S. N. F. in mix after adding cream. 



312 Ice Cream Mixes 

H = The pounds of M. S. N. F. short. 

H^ = The pounds of condensed whole milk 

K = The pounds of mix short. 

K^ = The pounds of mix possible to make. 

L .= The pounds of fat short. 

M := The pounds of mix before standardizing. 

M^ = The pounds of mix after adding cream. 

M^ = The pounds of mix desired. 

N = The percentage of M. S. N. F. in the original mix. 

N^ = The percentage of M. S. N. F. in the mix after adding 
the cream. 

=: The pounds of cream required. 

0^ = The pounds of butter required. 

P = The percentage of M. S. N. F. in the mix after add- 
ing condensed milk and cream. 

P'^ = The pounds of whole milk on hand. 

P^ = The pounds of whole milk required. 

R = The ratio of fat to M. S. N. F. 

S =: The percentage of M. S. N. F. in the milk powder. 

S- =: The pounds of milk powder. 

S =: The pounds of gelatin required. 

U = The pounds of sugar required. 

V := The percentage of sugar desired. 

V^ =z The percentage of T. S. in the gelatin. 

W =: The pounds of M^ater required. 

COMPOUNDING AN ICE CREAM MIX TO APPROXIMATE TESTS. 

The procedure to follow in making up the batch of ice 
cream mix before testing and accurately standardizing is illus- 
trated and explained in the directions here given, and by using 
the ice cream mix report illustrated under Fig 82. 

The first column of the left hand side of the report shows the 
raw materials on hand from which it is necessary to select the 
materials that are to be used in making up the batch. The per- 
centages of fat and M. S. N. F. in the different materials should 
be determined by tests made in advance, or the percentage may 
be taken from former tests of these substances received from 
the same source, provided that the composition does not vary 



Composition of Products 



313 



widely in different deliveries. In this problem, the percentages 
of fat and M. S. N. F. in the different materials used were de- 
termined in advance and may be found in their respective places 
in the report at the upper right hand side. 

When gelatin or other stabilizers are used they may be in- 
cluded with the M. S. N. F. In this batch .50 of one per cent of 
gelatin was added. 

Table 59 gives the average composition of the products most 
commonly used for making up ice cream mix. These results are 
accurate enough to use when compounding a mix to an approxi- 
mate test. 



TABLE 59. 
Approximate Composition of Products Used in Ice Cream Mix. 



Name of 
Product 


Per 
Cent 
Fat 


Per 

Cent 

M.S.N.F. 


Per 

Cent 
T. S. 


Name of 
Product 


Per 

Cent 
Fat 


Per 

Cent 
M.S.N.F. 


Per 
Cent 

Sugar 


Per 
Cent 
T. S. 


Butter 
Skim-milk 


84.00 
.10 


1.50 
8.70 


85.50 
8.80 


Plain cond. 
Skim-milk 


.50 


25.50 




26.00 








Fresh milk 


3.50 


8.50 


12.00 


Plain cond. 
whole milk 


6.00 


22.00 




28.00 








Cream 


15.00 
18.00 


7.88 
7.59 


22.88 
25.59 


" " 


8.00 


27.00 




33.00 


Cream 






Cream 


20.00 


7.41 


27.41 


Sweetened 
cond. skim- 
milk 


.50 


27.50 


42.00 


70.00 


Cream 


25.00 


6.94 


31.94 


Sweetened 
cond. whole 
milk 


8.00 


20.00 


42.00 


70.00 


Cream 


30.00 


6.48 


36.48 


Skim-milk 
powder 


1.00 


94.00 




95.00 








Cream 


40.00 


5.55 


45.55 


Whole milk 
powder 


26.00 


69.00 




95 00 








Cream 


50.00 


4.63 


54.63 


Sugar 






100.00 


100.00 










Evaporated 
whole milk 


7.80 


17.70 


25.50 


Gelatin 








86.00 












Evaporated 
skim-milk 


40 


22 00 


22.40 













314 



icE Cream Mixes 



Example 27: 
PROBLEM 2G: 



HOW TO COMPOUND ICE CREAM MIX TO 
APPROXIMATE TESTS. 



Products 


Pounds 


Per Cent 


Pounds 


Fat 


M. S. N. F. 


Fat 


M. S. N. F. 


Whole milk 


3400 


4.00 


8.50 


136.00 


299.00 






Skim-milk 


1360 


* 


8.70 




118.32 


Condensed skim-milk 


1300 




25,00 




325.00 


Butter 




84.00 












Skim-milk powder — 






95.00 







The above products are on hand and it is desired to utilize 
completely the first three products named, to make up a batch of 
10,000 pounds, the same to test 8.00 per cent of fat, 12.50 per 
cent of milk S. N. F., .50 per cent of gelatin, 13.00 per cent of 
sugar, making 34.00 per cent T. S. 

Solution Problem 26, Example 27: 

(1). To calculate the pounds of fat, M. S. N. F. and gelatin 
required. 

10000 X. 08=800, pounds of fat required. 
lOOOOX. 125=1250, pounds M. S. N. P. required. 
10000X.005=:50, pounds gelatin required. 
(2). To calculate the pounds of butter required. 
3400X. 04=136.00. pounds of fat in whole milk. 
800—136=664.00, pounds of fat to be supplied by the 

butter. 
664^.80=790.5, pounds of butter required. 
(3). To calculate the pounds of skim-milk powder required. 
3400X. 085=289.00, pounds of M. S. N. F. in whole milk. 
1360X. 087=118.32, pounds of M. S. N. F. in skim-milk. 
1300X. 25=325.00, pounds of M. S. N. F. in condensed 

whole milk. 
lOOOOX. 005=50.00, pounds of gelatin required. 
289.00+118.32+325.00=732.32, pounds of M. S. N. F. in 

four products to be added. 



Calculation of Water 315 

1250—732.32=517.68, pounds of M. S. N. F. to be provided. 
517.68-^.95=544.68, pounds of skim-milk powder to use. 

4. To Calculate the Pounds of Sugar Required. 

lOOOOX -13=1300, pounds of sugar. 

5. To calculate the pounds of water required. 

3400+1360+1300+50+790.50+544.68+1300=8745.18 
pounds of materials in mix. 
10000—8745.18=1254.82 pounds of water required. 

The complete batch after standardizing to approximate tests 
will contain the following materials : 

Whole milk 3400.00 pounds 

Skim-milk 1360.00 pounds 

Plain condensed skim-milk 1300.00 pounds 

Butter 790.50 pounds 

Skim-milk powder 544.68 pounds 

Gelatin 50.00 pounds 

Sugar 1300.00 pounds 

Water 1254.82 pounds 



10,000.00 pounds. 



The materials in the quantities as determined are mixed to- 
gether, homogenized and accurately sampled. The samples are 
immediately tested for fat and T. S. on the Mojonnier Tester. 
From the results obtained the final calculations are made to de- 
termine the materials to add in order to secure accurate stand- 
ardization. In making the calculation select and use the proper 
rule from those that follow in this chapter. When the percentage 
of fat or of M. S. N. F. in the mix are below the desired per- 
centage it is much more difficult to determine the exact amount 
of materials to add for correction, than it is to calculate the ma- 
terials to add when the fat and M. S. N. F. are present in excess. 
For this reason the aim should be always to have a small excess 
of fat and M. S. N. F. in the mix when this is made up before it 
is tested by the Mojonnier Tester for final accurate standard- 
ization. 



316 Ice Cream Mixes 

Providing- Factor of Safety. In all problems given in this 
chapter the calculations are made upon the basis of an absolute 
standard. A proper factor of safety should be allowed, and it is 
recommended that this be about .10 per cent upon the fat and 
.20 per cent upon the T. S. 

STANDARDIZING ICE CREAM MIX. 

Problem 27. How to calculate when making a definite weight 
of mix using a vacuum pan. 

Solution of Problem 27, Based Upon Rule 24 : 

(1). Multiply the pounds of mix desired by the percentage 
of M. S. N, F. desired. Divide the answer by the percentage of 
M. S. N. F. desired The answer will be the pounds of whole milk 
required. 

(2). Multiply the pounds of mix desired by the percentage 
of fat desired. Subtract from this product the pounds of fat in 
the whole milk, and divide the remainder by the percentage of fat 
in the butter. The answer will be the pounds of butter required. 

(3). Multiply the pounds of mix desired by the percentage 
of water free gelatin desired and divide the product by the 
percentage of T. S. in the gelatin. The answer will be the pounds 
of gelatin required. 

Multiply the pounds of mix desired by the percentage of 
sugar desired. The answer will be the pounds of sugar required. 

Solution of problem 27, based upon formula 24 : 

(1). To calculate the pounds of whole milk required. 

M- XB 

(2). To calculate the pounds of butter required. 

(M^- X A)— (P^ X E^) 

(3). To calculate the pounds of gelatin and of sugar required. 

M- XBi 

U = MXV 



Calculation of Whole Milk and Butter 
Problem 27, Example 28. 



317 





Per Cent 


Products 


Fat 


M. S. N. F. 


Gelatin 


Sugar 


T. S. 


Whole milk 


3.75 


8.50 






12.25 






Butter 


84.00 








84.00 






Gelatin 






84.00 




84.00 


Sugar 








100 


100.00 






Composition of mix de- 
sired 


8.00 


12.50 


.50 


13.00 


34.00 



It is desired to make 10,000 pounds of ice cream of the above 
tests, using the materials named. 

Solution of Problem 27, Example 28, based upon rule 24. 
(1). To Calculate the Pounds of Whole Milk Required. 

lOOOOX. 125=1250, pounds of M. S. N. F. required. 

1250— :-.085=: 14706, pounds of whole milk required. 
(2). To Calculate the Pounds of butter Required. 

lOOOOX. 08=800.00 pounds of fat required. 

14706 X. 0375=551.48, pounds of fat in whole milk. 

800.00—551.48=248.52, pounds of fat to be provided from 
"" butter. 

248.52-f-.84=295.90, pounds of butter required. 
(3). To Calculate the Pounds of Gelatin and Sugar Required. 

10000 X .005 

= 60, pounds gelatin required. 

10000 X. 13=1300, pounds of sugar required. 
Condense the above batch to such a concentration as to obtain 
10000 pounds of finished product. 

Solution of Problem 27, Example 28, based upon formula 24: 
(1). To calculate the pounds of whole milk required: 
P-=10000 X .125 



.085 



= 14706 



(2). To calculate the pounds of butter required. 

0^ ( 10000 X. 08 )— (14706 X -0375) 

^ — ^ -=295.90 

.84 



318 



Ice Cream ]\Iixes 



3). To calculate the pounds of gelatin and of sugar required. 

S-=10000X.005 



:60 



.84 

U=10000X. 13=1300 
Proof of Problem 27, Example 28 : 



Products 


Pounds 


Total 


Fat 


M.S.N.F. 


Gelatin 


Sugar 


T. S. 


Whole milk 


14706 


5.51.48 


1250.0 






1801 48 






Butter 


296.0 


248.52 








248.52 


Gelatin 


60.0 






60.0 




50.0 


Sugar 


1300 








1300 


1300.0 


Total pounds of batch after 
condensing and stand- 


10000 


800.00 


1250.0 


60.0 


1300 


3400.0 






Products 


Per Cent 


Fat 


M.S. N. F. 


Gelatin 


Sugar 


T. S. 


Whole milk 


3.75 


8.50 






12.25 






Butter 


84.00 








84.00 


Gelatin 






84.00 




84.00 


Sugar 








100.00 


100.00 


Tests of batch after cond 
standardizing 


ensing and 


8.00 


12.50 


.50 


13 00 


34.00 



Problem 28. How to Calculate When Making an Indefinite 
Weight of Mix Using a Vacuum Pan. 

Solution of Problem 28, Based Upon Rule 25 : 

(1). Multiply the pounds of whole milk by the percentage 
of M. S. N. F. in the whole milk. Divide the answer by the per- 
centage of M. S. N. F. desired. Call the answer A, or the pounds 
of mix possible to make from the whole milk on hand. Multiply 
A by the percentage of fat desired. Subtract from the answer 
the pounds of fat in the whole milk, and divide the remainder by 
the percentage of fat in the butter. The answer will be the 
pounds of butter required. 

(2). Multiply A by the percentage of w^ater free gelatin de- 
sired and divide the product by the percentage of T. S. in the 
gelatin. The answer will be the pounds of gelatin required. 
Multiply A by the percentage of sugar desired. The answer will 
be the pounds of sugar required. 



Weight for Vacuum Pan 



319 



Solution of Problem 28, based Upon Formula 25: 
(1). To calculate the pounds of butter required. 



0^= 



l(^)-l 



■(P^XE^) 



E^ 



(2). To calculate the pounds of gelatin and of sugar required. 

K^XB^ 



v^ 

U=KiXV 



Problem 28, Example 


29. 












Pounds 


Per Cent 


Products 


Fat 


M. S. N. F. 


Gelatin 


Sugar 


T. S. 


Whole milk 


10,000 


3.75 


8.50 






12.25 






Butter 




84.00 








84.00 








Gelatin 












84.00 








Sugar 










100.00 


100.00 








Composition of mix- 
desired, including 
gelatin 




8.00 


12.00 


.50 


13.00 


33.50 









It is desired to make all the ice cream mix possible from the 
above whole milk, using butter to supply extra fat required. 

Solution of Problem 28, Example 29, Based Upon Rule 25 : 

(1). To calculate the pounds of butter to use. 

lOOOOX. 085=850, pounds of M. S. N. F. in whole milk. 
850-f-.12=7083, pounds of mix possible to make. 
7083 X. 08=567, pounds of fat required. 
lOOOOX. 0375=375, pounds of fat in the whole milk. 
567 — 375=192, pounds of fat to be provided by butter. 
192^-.84=228, pounds of butter required. 
(2). To calculate the pounds of gelatin and of sugar required. 
7083 X. 005=35.4, pounds water free gelatin required. 
35.4-^-.84=42.0, pounds of gelatin required. 
7083 X. 13=921, pounds of sugar required. 



320 



Ice Cream Mixes 



Solution of Problem 28, Example 29, Based Upon Formula 25 : 
(1). To calculate the pounds of butter required. 



0.K 



10000 X .085) 
J2 



\ xt-otI 



X 7.07 1 — (10000 X .0375) 



.84 



228 



(2). To calculate the pounds of gelatin and of sugar required. 
7083 X. .005 

U=7083X. 13=921 
Condense the above batch to such a concentration as to obtain 
6800 pounds of finished product. 

Proof of Problem 28, Example 29 : 



Products 


Pounds 


Total 


Fat 


M.S. N.F. 


Sugar 


Total 


Whole milk 


10000 


375 


850 




1225 






Butter 


228 


192 






192 


Gelatin 


42 








35 


Sugar 


921 






921 


921 


Hotal pounds of batch 


708:? 


567 


850 


921 


2373 


Products 


Per Cent 


Fat 


M.S. N.F. 


Gelatin 


Sugar 


T. S. 


Whole milk 


3.75 


8.50 






12.25 






Butter 


84.00 








84.00 


Gelatin 






.50 




84.00 


Sugar 








13.00 


100.00 


Tests of batch 


8.00 


12.00 


.50 


13.00 


33.50 



PROBLEM 29: HOW TO CALCULATE WHEN THE FAT IS UNDER 

AND THE T. S. OVER THE STANDARD DESIRED. ALSO 

WHEN BOTH THE FAT AND THE T. S. ARE OVER 

THE STANDARD DESIRED, BUT WITH THE 

FAT IN A LOWER RATIO THAN THE T. S. 

See problem 30 for solution of second half of this problem. 
Cream sugar and water are to be used in standardizing. 

Solution of Problem 29, Based Upon Rule 26. 

(1). Divide the percentage of M. S. N. F. in the mix by the 
desired ratio between the fat and the M. S. N. F., and from the 
result, subtract the percentage of fat in the mix. Multiply the 



Calculation of Cream 321 

difference by the pounds of mix. Call the product L. 

Divide the percentage of M. S. N. F. in the cream by the 
desired ratio between the fat and the M. S. N. F., and subtract 
the result from the percentage of fat in the cream to be used for 
standardizing. Call the result E. Divide L by E. The 
quotient equals the pounds of cream to be added to the mix to 
bring the fat and the M. S. N. F. to the desired ratio. 

(2). Multiply the pounds of mix by the percentage of M. S. 
N. F. in the mix, and multiply the pounds of cream required by 
the percentage of M. S. N. F. in the cream. Divide the sum of 
the two products by the weight of the mix plus the weight of the 
cream. From the quotient subtract the percentage of M. S. N. F. 
desired in the mix. Multiply this difference by the pounds of 
mix plus the pounds of cream required, and divide the product 
by the desired percentage of M. S. N. F. in the mix. The quotient 
equals the pounds of mix short after adding the cream. 

(3). Add the pounds of cream required to the pounds of mix 
short, and multiply the sum by the percentage of sugar in the 
mix. The result equals the pounds of sugar to add. 

(4). Subtract the pounds of sugar from the pounds of mix 
short after adding the cream. The difference equals the pounds 
of water required. 

Solution of Problem 29, Ba^ed Upon Formula 26 : 
(1), To calculate the pounds of cream to add: 

°=l"Ki)-]-l(Ms)] 

(2). To calculate the pounds of mix short after adding the 
cream. 

N^=(MXN) + (0XD) Then K=(N^— B)M^ 
M^^ B ^ 

(3) . To calculate the pounds of sugar to add. 

U=(K— 0)XV 
(4). To calculate the pounds of water required. 



322 Ice Cream Mixes 

Problem 29, Example 30. 





Pounds 


Per Cent 


Products 


Fat 


M. S. N. F. 


Sugar 


T. S. 


Mix before standard- 
izing 


10000 


7.79 


13.80 


13.00 


34.59 










40.00 


5.20 




45.20 






Sugar 








100.00 


100 . 00 






Composition mix de- 
sired 




8.00 


13.00 


13.00 


34.00 







Ratio of fat to M. S. N. F. desired 1 to 1.625. 
Mix before standardizing contains .50 per cent of gelatin 
which is included with the M. S. N. F. 

Solution of Problem 29, Example 30, Based upon Rule 26 : 
(1). To calculate the pounds of cream to add. 

13.80-4-1.625=8.49, per cent of fat necessary to equalize 

M. S. N. F. in unstandardized mix. 
8.49— 7.79=. 70, per cent of fat short. 
lOOOO.OOX. 007=70.00, pounds of fat short. 
5.20^1.625=3.20, per cent of fat to equalize the M. S. N. F. 

in the cream. 
40.00 — 3.20=:36.80, per cent of fat in the cream available 

for standardizing. 
70.00-^-.368r= 190.22, pounds of cream required. 
(2). To calculate the pounds of mix short after adding the 
cream. 

lOOOOX. 138=1380.00 pounds of M. S. N. F. in the mix. 
190.22X. 052=9.89, pounds of M. S. N. F. in the cream. 
1380.00+9.89=1389.89, pounds of M. S. N. F. in the mix 

and cream together. 
1389.89^-10190.22=13.64, per cent of M. S. N. F. in the 

mix and cream together. 
13.64— 13.00=. 64, per cent excess M. S. N. F. in mix after 

adding the cream. 
10190.22X.0064=65.12, pounds of excess M. S. N. F. 
65.12-f-.13=500.88, pounds of mix short. 
(3). To calculate the pounds of sugar to add: 

500.88+190.22=691.08, pounds of mix short plus pounds 

of cream. 



Calculation of Shortage 



323 



691.08 X. 13=89.84, pounds of sugar to add. 
(4). To calculate the pounds of water required. 

500.88 — 89.84=411.04, pounds of water required. 
Solution of Problem 29, Example 30, Based Upon Formula 26. 
(1). To calculate the pounds of cream to add. 



= 



[l0000x(j5)-7.79)] 



= 190.22 



(2). 
cream. 



To calculate the pounds of mix short after adding the 



N' 



(10000X.138) + (190.22X.052; 



K: 



10190.22 

(.1364— .13)X10190.22 
l3 



13.64 



=50. 



(3). To calculate the pounds of sugar to add. 

U= (500.88+190.22) X.13=89.84 
(4) . To calculate the pounds of water required. 

W=:500.88— 89.84=411.04 

Proof of Problem 29, Example 30 : 







Pound 


Per Cent 


Materials in Batch 


Fat 


Milk 
S. N. F. 


Sugar 


Fat 


Milk 

S. N. F. 


Sugar 


T. S. 


Mix before standardizing . 


10000 


779.00 


1380 


1300 


7.79 


13.80 


13.00 


34.59 


Cream added 


190 


76.00 


10.00 




40.00 


5.20 




45.20 








90 






90 






100.00 










411 




















Total after standardizing . 


10691 


855 . 00 


1390 


1390 


8.00 


13.00 


13.00 


34.00 



PROBLEM 30. HOW TO CACULATE WHEN BOTH THE FAT 
AND THE T. S. ARE OVER THE STANDARD DESIRED, 
BUT WITH THE FAT IN A LOWER RATIO 
THAN THE T. S. 

This problem is very similar to problem 29, but for the sake 
of clarity its complete solution is here given. Cream, sugar and 
water are to be used in standardizing. 



324 Ice Cream Mixes 

Salution of Problem 30, Based Upon Rule 27 : 

(1). Divide the percentage of M. S. N. F, by the desired 
ratio between the fat and the M. S. N. F, and from the quotient 
subtract the percentage of fat in the mix. Multiply the difference 
by the pounds in the mix. Call the product L, or pounds of fat 
short. Divide the percentage of M. S. N. F. in the cream by the 
desired ratio between the fat and the M. S. N. F. and subtract 
the quotient from the percentage of fat in the cream. Call the 
difference E., or the percentage of fat available in the cream for 
standardizing. Divide L by E., and call the quotient 0, or the 
pounds of cream required. 

(2). Multiply the pounds in the original mix by the per- 
centage of fat that it contains, and multiply the pounds of cream 
by the percentage of fat in it. Add the two products together 
and divide the sum by the number of pounds in the mix after 
adding the cream. From the quotient subtract the desired per- 
centage of fat, and multiply the difference by the pounds of 
original mix plus the pounds of cream required. The product 
thus obtained, divided by the desired percentage of fat in the mix, 
equals the pounds of mix short after adding the cream. 

(3). Add the pounds of cream required to the pounds of mix 
short and multiply the sum by the percentage of sugar desired. 
The product equals the pounds of sugar required. 

(4). Subtract the pounds of sugar from the pounds of mix 
short. The difference equals the pounds of water to add. 

Solution of Problem 30, Based Upon Formula 27: 
(1). To calculate the pounds of cream required. 

= [Mx(i)-F].[c-Q] 

(2). To calculate the pounds of mix short after adding- the 
cream. 

r(MxF) + (OxC) 1 

^- iSyTTcr -AJx(M+o ) 

A 

(3). To calculate the pounds of sugar required, 

TJ=(K+0)V 



Calculation oi^ Cream 



325 



(4). To Calculate the Pounds of Water Required. 
W=K— U 

Problem 30, Example 31 : 





Pounds 


Per Cent 


Products 


Fat 


M. S. N. F. 


Sugar 


T. S. 


Mix 


10,000 


8.10 


13.70 


13.00 


34.80 


Cream 




40.00 


5.20 




45.20 


Sugar 










100.00 


Water 












Desired composition 




8.00 


13.00 


13.00 


34.00 



Mix before standardizing contains .50 per cent of gelatin 
which is included with the M. S. N. F. 

Solution of Problem 30, Example 31, Based Upon Rule 27: 
(4). To calculate the pounds of cream required. 

13.70^1.625=8.43, per cent of fat to equalize the M. S. N. F. 

8.43—8.10^.330, per cent of fat short. 

lOOOO.OOX. 0033=33.00, pound of fat short. 

5.20-f-l. 625^3. 20, per cent fat required to equalize the 

M. S. N. F. in the cream. 
40.00 — 3.20:=36.80, per cent fat in the cream available for 

standardizing. 
33.00-^.368:=89.86, pounds of cream required. 

(2). To calculate the pounds of mix short after adding" the 
cream. 

lOOOOX. 081=810.0, pounds of fat in the mix. 
89.86X.40=35.95, pounds of fat in the cream. 
810.00+35.946=845.95, pounds of fat in the mixture. 
10000+89.86=10089.86, pounds of mix and cream. 
845.95^10089.86=8.384, per cent of fat in the mixture. 
8.384—8.0=0.384, per cent fat excess. 
10089.86X. 00384=38.745, pounds of fat excess. 
38.745^.08=484.3, pounds of mix short after adding the 
cream, 



326 



Ice Cream Mixes 



(3) . To calculate the pounds of sugar. 

484.34 89.86=574.16, pounds of mix short plus pounds of 
cream. 

574.16X -13=74.64, pounds of sugar required. 
(4). To calculate the pounds of water required. 

484.3 — 74.64r=409.66, pounds of water required. 
Solution of Problem 30, Example 31, Based Upon Formula 27 : 
(1). To calculate the pounds of cream required. 



riooooxr^^"^— -osil 

n=l \l.625j J 

[-{ri)l 



= 89.86 



(2). To calculate the pounds of mix short after adding the 
cream. 

■(10000 X.081) + (89.86 X.40) 



K = 



10000 + 89.86 



'1 



081 X 10000 + 8986) = 484.3 



.08 

(3). To calculate the pounds of sugar required. 

U= (484.3+89.86) X. 13=74.64 
(4). To calculate the pounds of water required. 
W=484.30— 74.64=409.66 



Proof of Problem 30, 


Example 31 : 










Materials 




Pounds 


Per Cent 


Batch 


Fat 


M.S.N.F. 


Sugar 


T. S. 


Fat 


M.S.N.F. 


Sugar 


T. S. 


Mix 


10000 


810.0 


1370. 


1300 


3480.0 


8.10 


13.70 


13.00 


34.80 




90 


36.0 


5.00 




71.0 


40.00 


5.20 




45.20 










Sugar 


75 






75. 


75.0 






100.00 


100,00 












Water 


409 




































After 
standard- 
izing 


10574 


846 


1375 


1375 


3596 


8.00 


13.00 


13.00 


34.00 



PROBLEM 31: HOW TO CALCULATE WHEN THE FAT AND 

THE M. S. N. F. ARE BOTH UNDER THE STANDARD 

DESIRED. 

Butter, skim-milk powder and sugar are to be used for 
standardizing under this problem. Example 32 shows how to 



Steps in Calculation 327 

solve this problem when using these products. Concentrated 
cream and condensed whole milk can also be used, as indicated 
by the solution under problem 32. 

Two methods of calculation are possible when using concen- 
trated cream and condensed whole milk. The second method as 
indicated under example 34 was originated by J. A. Cross. 

Solution of Problem 31, Based Upon Rule 28 : 

(1). Subtract the percentage of fat in the mix from the per- 
centage of fat desired, and multiply the difference by the weight 
of the mix. Divide the product by the percentage of fat in the 
butter. The quotient will be the pounds of butter required. 

(2). Subtract the percentage of M. S. N. F. in the mix from 
the percentage of M. S. N. F. desired, and multiply the difference 
by the weight of the mix. Divide the answer by the percentage 
of T. S. in the skim-milk powder. The answer will be the pounds 
of skim-milk powder required. 

(3). The pounds of butter plus the pounds of skim-milk 
powder multiplied by the percentage of sugar required equals the 
pounds of sugar required. The pounds of butter plus the pounds 
of sugar plus the pounds of milk powder equals the total weight 
of material to be added for standardizing. 

(4). Another calculation is necessary to standardize the ma- 
terial added which itself requires to be standardized. Multiply 
the total weight of material added for standardizing b}' the per- 
centage of fat desired, and divide the product by the percentage 
of fat in the butter. The result equals the pounds of butter 
required. 

(5). Multiply the total weight of material added for standard- 
izing by the percentage of M. S. N. F. desired and divide the 
product by the percentage of T. S. in skim-milk powder. The 
quotient equals the pounds of skim-milk powder required. 

(6). Multiply the total weight of materials added for stand- 
ardizing by the percentage of sugar desired. The product equals 
the pounds of sugar required. 

(7). The materials to be added under 3, plus the materials 
to be added under 4, 5, and 6, equals the total materials to be 
added in standardizing the batch. The batch will still not be 



328 Ice Cream Mixes 

completely standardized because the products added under 5 and 
6 require to be standardized also. An unstandardized remainder 
can thus be continued indefinitely, but the amount gradually 
becomes smaller and as a rule only one extra standardization is 
necessary. 

Solution of Problem 31, Based Upon Formula 28: 
(1) . To calculate the pounds of butter required. 

[MX(A-F)] 

O - J,: 

(2). To calculate the pounds of skim-milk powder required. 

[MX(B-N)] 

(3) . To calculate the pounds of sugar required. 

To calculate the extra pounds of each material necessary to 
standardize the material added in the first standardization. 

(4). To calculate the pounds of butter required, second 
standardization. 

^,^_KO^+S^+U) A] 



(5). To calculate the pounds of skim-milk powder required, 
second standardization. 

'^- S 

(6). To calculate the pounds of sugar required, second 
standarization. 

Note: In the second standardization the factors 0^, S^ and U 
in the formula to the right of the equality sign represent the 
pounds of butter, skim-milk powder, and sugar respectively, as 
determined in the first standardization. 



Calculation of Products 
Problem 31, Example 32. 



329 





Pounds 


Per Cent 


Products 


Fat 


M. S. N. F. 


Sugar 


T. S. 


Mix 


10,000 


7.60 


12.10 


13,00 


32.70 


Butter 




80,00 






80.00 


Skim-milk powder 






95.00 




95.00 


Sugar 








100.00 


100.00 


Composition desired 




8.00 


13.00 


13.00 


34.00 


Desired ratio of fat to M. S. N. F. in the mix is 1 to 1.625. 



Mix before standardizing contains .50 per cent gelatin which 
is included with the above M. S. N. F. 

Solution of Problem 31, Example 32, Based Upon Rule 28 : 
(1). To calculate the pounds of butter required. 

8.00— 7.60:^.40, per cent of fat short. 

lOOOO.OOX. 004=40, pounds of fat short. 

40.00-f-.80:=:50, pounds of butter required. 
(2). To calculate the pounds of skim-milk powder required. 

13.00— 12.10=:.90, per cent of M. S. N. F. short. 

10000 X. 009 r= 90, pounds of M. S. N. F. short. 

90-^.95^94.74, pounds of skim-milk powder short. 
(3). To calculate the pounds of sugar required. 

50-f 94.74r=144.74, pounds of butter and skim-milk powder 
required. 

144.74X -13=18.82, pounds of sugar required. 
To calculate the extra pounds of each material necessary to 
standardize the material added in the first standardization. 
(4). To calculate the pounds of butter required. 

50-f 94.74+18.82=163.56, pounds of material added. 

163.56 X. 08=13.08, pounds of fat required. 

13.08-f-.80=:16.36, pounds of butter required. 
(5) . To calculate the pounds of skim-milk powder required. 

50+94.74+18.82=163.56, pounds of material added. 

163.56X.13=21.26, pounds of M. S. N. F. required. 

21.26-^.95=22.40, pounds of skim-milk powder required. 



330 Ice Cream Mixes 

(6). To calculate the pounds of sugar required. 

50+94.74+18.82rrrl63.36, pounds of material added. 
163.36X -13=21.26, pounds of sugar required. 

(7). To calculate total pounds of each material required. 
50-fl6.36=66.36, pounds of butter required. 
94.74+22.40=117.14, pounds of skim-milk powder required. 
18.82+21.26=40.08, pounds of sugar required. 

Solution to Problem 31, Example 32, Based Upon Formula 28 : 
(1). To calculate the pounds of butter required. 

10000X(.08— .076) 

0= M =^« 

(2). To calculate the pounds of skim-milk powder required. 

10000X(.13— .121) 

S^= ^ =94.74 

.9.5 

(3). To calculate the pounds of sugar required. 

U= (50+94.74) X.13=18.82 
(4). To calculate the pounds of butter required, second 
standardization. 

(50+94.74+18.82) X.08 

«■= Jo =''■'' 

(5). To calculate the pounds of skim-milk required, second 
standardization. 

(.50+94.74+18.82) X. 13 
S^= g^ — — =22.40 

(6). To calculate the pounds of sugar required, second 
standardization. 

U= (50+94.74+18.82) X.1300=21.26 

The addition of butter and skim-milk powder is not practicable 
unless they can be added before the batch is pasteurized and 
homogenized. 



Fat and T. S. Under Standard 



331 



Proof of Problem 31, Example 


32. 










Products 




Pounds 


Per Cent 




Fat 


M.S.N.F. 


Sugar 


T.S. 


Fat 


M.S.N.F. 


Sugar 


T.S 


Mix 


1000 


760.00 


1210.0 


1300 


3270 


7.60 


12.10 


13.00 


32.70 


Butter 


66.36 


53.08 








80.00 






80 00 
















Skim-milk 


117.14 




105.7 




105.7 




95.00 




95.00 












40.08 






40.08 








100.00 


100 00 
















Standardized 
products 


10223.00 


813.08 


1315.7 


1340.08 


3375.7 


7.95 


12.90 


13.11 


33.96 



PROBLEM 32: HOW TO CALCULATE WHEN THE FAT AND 
T. S. ARE BOTH UNDER THE STANDARD DESIRED. 

Solution of problem 32, based upon rule 29. Under this 
modification of problem 31, the use of concentrated cream and 
condensed whole milk is contemplated in effecting standardization. 

(1). Subtract the percentage of fat desired from the per- 
centage of fat in the mix. Multiply the remainder by the pounds 
of mix. Call the answer A. Divide the percentage of M. S. N. F. 
in the cream by the ratio between the fat and the M. S. N. F. 
desired and subtract the answer from the percentage of fat in the 
cream. Divide A by the remainder. The answer will be the 
pounds of cream required. 

(2). Multiply the pounds of cream required and the pounds 
of mix by their respective percentages of M. S. N. F. and add the 
two products together. Divide the sum by the combined pounds 
of mix and cream required. The answer will be the percentage of 
M, S. N. F. in the mixture. 

(3). Subtract the percentage of M. S. N. F. in the mixture 
from the percentage of M. S. N. F. desired and multiply the 
combined pounds of mix and cream by the remainder. Call the 
product B, or the pounds of M. S. N. F. short. Multiply the per- 
centage of fat in the condensed milk by the ratio, and subtract the 
answer from the percentage of M. S, N. F. in the condensed milk. 
Divide B by the remainder. The answer will be the pounds of 
condensed milk required. 

(4), Multiply the pounds of cream and condensed milk used 
by the percentage of sugar desired to obtain the pounds of sugar 
required. 



332 



Ice Crp^am Mixes 



Solution of Problem 32, Based Upon Formula 29 : 
(1). To calculate the pounds of cream required to supply the 
fat short in the mix. 

o=[;axf)xm]^[c-(?)] 

(2). To calculate the percentage of M. S. N. F. in the mix 
after adding the cream. 

(0XD) + (MXN) 



N^ 



(0+M) 



(3). To calculate the pounds of condensed milk required after 
adding the cream. 

H^^ (B— NO X (M+0)-^-[F^X (C^XR) ] 
(4). To calculate the pounds of sugar required. 

U=(0+HOV. 
Problem 32, Example 33 : 



Products 


Pounds 


Per Cent 


Fat 


M. S. N. F. 


Sugar 


T. S. 


Mix 


10,000 


7.60 


12.70 


13.00 


33.30 


Cream 




40.00 


6.00 




46.00 


Condensed milk 




10.50 


25.50 




36.00 






Composition desired 




8.00 


13.00 


13.00 


34.00 



Desired ratio of fat to M. S. N. F. is 1 to 1.625. 



Mix before standardizing contains .50 per cent of gelatin 
which is included with the above M. S. N, F. 

Solution of Problem 32, Example 33, based Upon Rule 29 : 

(1). To calculate the pounds of cream required to supply the 
fat short in the mix. 

8.00— 7.60r=.40, per cent of fat short. 
lOOOOX. 004=40, pounds of fat short. 



Cai,cui.ations 333 

6.00-^-1.625=3.70, per cent of fat to equalize the M. S. N. F. 
in the cream. 

40.00—3.70=36.30, per cent of fat available for standard- 
izing in the cream. 

40h-.363=110.2, pounds of cream required. 

(2). To calculate the percentage of M. S. N. F. in the mix 
after adding the cream. 

110.2X. 06=6.61, pounds of M. S. N. F. in the cream. 

lOOOOX. 127=1270, pounds of M. S. N. F. in the original 
mix. 

1270+6.12=1276.12, pounds in both. 

10000-f 110.2=10110.2, pounds of mix plus cream. 

1276.12-^10110.2=12.62, per cent M. S. N. F. in the mix- 
ture. 

(3). To calculate the pounds of condensed milk required. 

13.00— 12.62=.38, per cent of M. S. N. F. short. 
10110.2X. 0038=38.4, pounds of M. S. N. F. short. 
10.50X1.625=17.06, per cent of M. S. N. F. to equalize the 

fat in the condensed milk. 
25.5—17.06=8.44, per cent of M. S. N. F. available for 
standardizing in the condensed milk. 

38.40-H-.0844=443, pounds of condensed milk required. 
(4). To calculate the pounds of sugar required 

443-|-110.2=553.2, pounds of cream and condensed milk, 
553, 2 X. 13=73, pounds of sugar required. 

Solution of Problem 32, Example 33, Based Upon Formula 29: 
(1). To calculate the pounds of cream required to supply the 
fat short in the mix. 

[(8.00— 7.60) X 10000] 
0=^^^ ^=110.2 



[^^•««-(S] 



(2) . To calculate the percentage of M. S. N. F. in the mix after 
adding the cream. 

(110,2X6.00) -f- (10000X12.70) 

N^rz^ 19 fi9 

[10000+110.2] —L'i.O^ 



334 



Ice Cream Mixes 



(3). To calculate the pounds of condensed milk required after 
adding the cream. 

(.1300X.1262) X (10000—110.2) 



H^ 



.255X (.105X1.625) 

(4). To calculate the pounds of sugar required. 

U= (110.2+443) X.13^73.00 
Proof of Problem 32, Example 33 : 



443 



Products 




Pounds 


Per Cent 




Fat 


M S.N.F 


Sugar 


T.S. 


Fat 


M.S.N.F. 


Sugar 


T.S 


Mix 


10000 


760.00 


1270 


1300 


3330 


7.60 


12.70 


13.00 


33.30 


Cream 


110.2 


44.08 


6.12 




50.2 


40.00 


6.00 




46.00 










Condensed 
whole milk 


443.0 


46.51 


112.96 




159.47 


10.50 


25.50 




36.00 










Sugar 


73.0 






73 


73.00 






100.00 


100.00 














Standardized 
product 


10626.2 


850.59 


1389.08 


1373 


3612.67 


8.00 


13.07 


12.92 


33.00 



The above method of standardization does not give results 
that check out exactly, as the proof indicates. 

PROBLEM 33: HOW TO CALCULATE WHEN THE FAT AND 

THE M. S. N. S. ARE BOTH UNDER THE STANDARD 

DESIRED. 

The problem is the same as problems 31 and 32. As in the 
ease of these problems the use of concentrated cream and con- 
densed skim-milk or of butter and skim-milk powder is contem- 
plated in effecting standardization. The method of calculation 
shown under this problem is that originated by Jos. A. Cross. 
This method of calculation can be used upon problem 33, and 
also in the case of problems in which either the fat or T. S. are 
correct, but one or the other are low. 

Principles of Cross Method of Calculation. This method is 
based upon making the calculations for two theoretical mixtures 
of dairy products from materials on hand available for standard- 
izing. Mixture No. 1, to contain an excess of fat available for 
standardizing. Mixture No. 2, to contain an excess of M. S. N. F. 
available for standardizing. If the tests of the materials on 
hand are known, these calculations can be made before testing 



Rectangle Method 335 

the mix that is to be standardized, thereby saving time in making 
the final calculations. It is not necessary to make the actual 
mixtures of materials. The materials can be added in the pro- 
portions found necessary by the calculations. This method merits 
close study, and it is highly recommended since it gives abso- 
lutely accurate results all in one calculation. 

How to Calculate Theoretical Mixtures No. 1, in which the 
M. S. N. F. is Standard and the Fat is Above Standard. When 

standardizing material is added to a batch of ice cream mix, a 
proportionate amount of sugar must be incorporated in order to 
produce no change in the sugar content of the standardized batch. 
If a mix tests 14.94 per cent of M. S. N. F. without sugar, it will 
test 13 per cent of S. N. F. after the correct amount of sugar is 
added in the case of a mix testing 8.00 per cent of fat, 13.00 per 
cent of M. S. N. F. and 13.00 per cent of sugar. This is found by 
subtracting 13.00 per cent of sugar from 100.00 and dividing 13.00 
per cent of M. S. N. F. by 87. Likewise this mix will contain 9.20 
per cent of fat found by dividing 8.00 per cent by 87. The fol- 
lowing mix is calculated to test 14.94 per cent of M. S. N. F. 

Materials to be used. Condensed skim-milk testing .50 per 
cent fat, 25.00 per cent S. N. F. and cream testing 40.00 per cent 
fat, 5.34 per cent M. S. N. F. Use Dr. Pearson's method for mak- 
ing the calculation, and calculate the percentage of fat available 
for standardizing in the mixture, as follows : 

Cond. skim-milk=25.00 ' 9.60 




Cream=5.34 10.06 



10.06-|-9. 60= 19.66, sum of condensed skim-milk and cream 

units to use. 
9.60-^-19.66^48.80, per cent of condensed skim-milk. 
10.06-^19.66=51.20, per cent of cream. 
51.2 parts of cream=20.46 parts of fat and 2.74 parts of 

M. S. N. F. 
48.80 parts of condensed skim-milk=.24 parts of fat and 

12.20 parts of M. S. N. F. 



336 let Cream Mixes 

100.0=20.70 parts of fat, 14.94 parts of M. S. N. F. 

20.7 — 9.20=11.50, available per cent of fat in the mixture 
which can be used for standardizing. 
As calculated above, a mixture of 48.8 parts of 40 per cent 
cream and 51.2 parts of 25 per cent condensed skim-milk will 
test 14.94 per cent in solids not fat, which will be reduced to 13 
per cent after the proper amount of sugar is added to the mix. 
Any desired amount of this mixture may be added to a batch of 
ice cream mix testing 13 per cent S. N. F. without changing S. N. 
F. test of the standardized mix. It tests, however, 11.50 per cent 
higher than standard in butter fat and every 100 pounds added 
(plus 14.94 pounds of sugar) will make up a deficit of 11.5 pounds 
of fat in the mix to be standardized and will leave the percentage 
of M. S. N. F. and the percentage of sugar unchanged. 

It is, of course, unnecessary to actually make up this mixture. 
If the tests of the mixture to be standardized shows that it is 
standard in M. S. N. F. but requires 11.5 pounds of fat, add 48.8 
pounds of the condensed and 51.2 pounds of 40 per cent cream 
and 14.94 pounds of sugar. If the deficit is 23 pounds of fat add 
twice the above amounts etc. 

Other combinations using cream of different percentages and 
condensed milk of different concentration may be calculated and 
a record of the proportions necessary should be kept on file. These 
combinations may be made to cover any composition of mix de- 
sired. 

A few combinations of commonly used standardizing materials 
are given in Table 60. These are all based upon a mix contain- 
ing 8.00 per cent fat, 13.00 per cent of M. S. N. F., 13.00 per cent 
of sugar, making 34.00 per cent T. S. All of them will test 14.94 
per cent of solids not fat and will have fat in excess and avail- 
able for standardizing as indicated. 

How to Calculate Theoretical Mixture No. 2 in Which the Fat 
is Standard and the M. S. N. F. is Above Standard. The calcula- 
tion of this mixture is the same as in the case of mixture No, 1 
except that it is made standard in fat, and used to raise the 
M. S. N. F. test of the mix to be standardized. In order to test 
8.00 per cent of fat after sugar is added the mixture must test 
9.20 per cent before adding the sugar, if it is to contain 13.00 



Various Combinations 



337 



per cent of sugar. Therefore, the following is calculated to test 
9.20 per cent of fat and a« much above 14,94 per cent of M. S. N. F. 
as possible. 

Materials to be used — 40.00 per cent cream testing 5.34 per 
cent of M. S. N. F. and condensed skim-milk testing .50 per cent 
of fat, 25.00 per cent of M. S. N. F. 

TABLE 60 
A few combinations of cream and condensed milk containing an excess 
of fat available for standardizing. 



Com- 
bination 
No. 


Cream 


Condensed Milk 


Parts 
Cream 
to Use 


Parts 

Condensed 

Milk to 

Use 


Percentage 
Fat in 
Mixture 
Available 
for Stand- 
ardizing. 


Per Cent 


Per Cent 




Fat 


M. S. N. F. 


Fat 


M. S. N. F. 


1 


20.00 


7.12 


.50 


25.00 


63.35 


36.65 


3.65 


2 


25.00 


6.75 


.50 


25.00 


55.12 


44.88 


4.80 


3 


30.00 


6.23 


.50 


25.00 


53.60 


46.40 


6.11 


4 


40.00 


7.80 


7.80 


17.70 


22.30 


77.70 


5.78 


5 


40.00 


5.23 


5.00 


25.00 


51.17 


48.83 


13.71 



Use Dr. Pearson's method for making the calculation and 
calculate the percentage of M. S. N. F. available for standardizing 
in the mixture as follows : 

Cream=40.00 8.7 



9.20 



Cond. skim-milk 30.8 

.50 
8.7+30.8=39.5 

8.70-f-.396=22, per cent of cream. 
30.80-^.396=78, per cent of condensed skim-milk . 
78 parts of condensed skim-milk contains .40 parts fat, 19.5 
parts M. S. N. F. 

22 parts of cream contains 8.80 parts fat, 1.17 parts M. S. N. F. 
100 parts of the mixture contain 9.20 parts fat 20.67, parts 
M. S. N. F. 



338 



Ice Cream Mixes 



20.67—14.94=5.73, per cent of M. S. N. F. above standard and 
available for raising the M. S, N. F. test of low testing ice cream 
mix. 

As calculated above, a mixture of 78 parts of condensed skim- 
milk and 22 parts of cream will make a mix testing standard in 
fat, after 14.94 pounds of sugar is added per hundred. It will 
test, however, 5.73 per cent higher in M. S. N. F. than standard 
and therefore every hundred pounds added to an ice cream mix 
(with the proper amount of sugar) will make up a deficit of 
5.73 pounds of M. S. N. F. without changing either the fat or the 
sugar test of the final mix. 

Other combinations of dairy products with different tests are 
given in Table 61. Each will test standard in fat but will have 
an excess of M. S. N. F. as indicated. 

TABLE 61 

A few combinations of dairy products, containing an excess of M. S. N. F. 
available for standardizing. 





Cream 


Condensed Milk 


Parts of 
Cream 
to Use 


Parts 

Condensed 

Milk to 

U.se 


Percentage 


Combi- 
nation 


Per Cent 


Per Cent 


M. S. N. F. 
in Mixture 


No. 


Fat 


M. S. N. F. 


Fat 


M. S. N. F. 


Available for 
Standardizing 


6 


20.00 


7.12 


.50 


25.00 


44.60 


55.40 


2.08 


7 


30.00 


6.23 


.50 


25.00 


29.50 


70.50 


4.52 


8 


40.00 


5.34 


7.80 


17.70 


4.35 


95.65 


2.22 


9 


40.00 


5.34 


5.00 


25.00 


12.00 


88.00 


7.70 


10 


Butter 
83.00 


Skim-mil 
1.00 


k powde 
1.00 


95.00 


BUTTER 

10.00 


SKIM-MILK 
POWDER 

90.00 


69.66 



Having calculated the theoretical mixtures Nos. 1 and 2, and 
calculated the available percentage of fat and M. S. N. F. respec- 
tively, it then becomes a simple matter to calculate the pounds 
of dairy products and sugar necessary to add to raise the test 
of the mix to the point desired. 

The method of calculation recommended is fully illustrated 
under example 34. 



Calculation of Fat 
Problem 33, Example 34: 



339 



Products 


Pounds 


Per Cent 


Fat 


M. S. N. F. 


Sugar 


T. S. 


Mix before standardizing 


10,000 


7.80 


12.60 


13.00 


33.40 


Cream 




40.00 


5.40 




45.40 


Condensed milk 




.50 


25.00 




26.00 


Composition desired 




8.00 


13.00 


13.00 


34.00 



Ratio of fat to M. S. N. F. desired is 1 to 1.625. 



Mix before standardizing contains .50 per cent gelatin which 
is included with the above M. S. N. F. 

Solution of Problem 33, Example 34, Based Upon Calculation 
only. 

(1). To calculate the fat, and M. S. N. F. to provide, when 
sugar is to be added after standardizing. Also to calculate the 
percentage of sugar necessary when this is added to the standard- 
ized mix. 

100 — 13=87.00, per cent of total products in mix besides 
sugar. 

8.00^.87=9.20, per cent of fat that the mix should eon- 
tain if sugar is to be added after standardizing. 

13.00^.87=14.94, per cent of M. S. N. F. the mix should 
contain if sugar is to be added after standardizing. 

13.00^.87=14.94, per cent of sugar to add to milk 
products only to yield a mix containing 13.00 per cent 
of sugar. 

(2). To calculate the fat available for standardjizing- in 
theoretical mixture No. 1. 



Condensed skim-milk=:25.00 



Cream=5.40 



9.54 



14.94 



10.06 



340 Ice Cream Mixes 

14.94 — 5.40=9.54, the units of condensed skim-milk to use. 

25.00—14.94=10.06, the units of cream to use. 

9. 54+10.06=19. 60, the sum of the condensed skim-milk and 
cream units to use. 

9.54-^.196=48.67, the per cent of condensed skim-milk to 
use. 

10.06-^.196:=51.33, the per cent of cream to use. 

48.67 X -50=. 24, per cent of fat in mixture derived from 
condensed skim-milk. 

51.33X -40=20.53, per cent of fat in mixture derived from 
cream. 

20.53+.24=20.77, per cent of fat in mixture derived from 
both condensed skim-milk and cream. 

20.77—9.20=11.57, per cent of fat in mixture No. 1, avail- 
able for standardizing. 

(3). To calculate the available M. S. N. F. in theoretical 
mixture No. 2. 

Cream 40.00 8.20 




Condensed 

skim-milk 1.00 30.80 

40.00 — 9.20=30.80, units of condensed skim-milk to use. 

9.20—1.00=8.20, units of cream to use. 

8.20+30.80=39.00, the sum of the condensed milk and 
cream units to use. 

30.80-f-.39=78.97, the per cent of condensed skim-milk 
required. 

8.20-^.39=:21.03, the per cent of cream to use. 

78.97 X. 25=19.74, the per cent of M. S. N. F. in the 
mixture derived from the condensed skim-milk. 

21.03X.054=1.14, the per cent of M. S. N. F. in the mixture 
derived from the cream. 

19.74+1.14=20.88, the per cent of M. S. N. F. in the mix- 
ture derived from both the condensed skim-milk and 
cream. 



Calculations 341 

20.88—14.94=5.94, the per cent of M. S. N. F. in mixture 
No. 2 available for standardizing, 

(3). To calculate the pounds of fat short and the pounds of 
mixture No. 1 required to provide the pounds of fat short. 

8.00— 7.80==. 20, the per cent of fat short. 
10000 X.004=40, pounds of M. S. N. F. short. 
20-^ .1157=173, pounds of mixture No. 1 required. 

(4). To calculate the pounds of M. S. N. F. short, and the 
pounds of mixture No. 2 required to provide the pounds of 
M. S. N. F. short. 

13.00— 12.60=:.40, per cent of M. S. N. F. short. 
lOOOOX. 40=40, pounds of M. S. N. F. short. 
40.00-=-.0594=675, pounds of mixture No, 2 required. 

(5). To calculate the pounds of cream and condensed skim- 
milk required under 3 and 4, also the extra sugar required. 

173.x •5133:=88, 80, pounds of cream required from mixture 
No. 1. 

674X. 2103=141, 53, pounds of cream required from mix- 
ture No. 2. 

88.80+141.53=230.44, total pounds of cream required. 

173X. 4867=84.20, pounds of condensed skim-milk required 
from mixture No, 1. 

673X.7897=531.47, pounds of condensed skim-milk re- 
quired from mixture No. 2. 

84,20+531,47=615.66, total pounds of condensed skim- 
milk required, 

230.33+615,66=845.99, total pounds of cream and con- 
densed skim-milk required. 

845.99 X -1494= 126.39, pounds of sugar required in stand- 
ardizing. 
Therefore add for standardizing: 

230.33 pounds of 40.00 per cent cream. 

615.66 pounds of 25.00 per cent condensed skim-milk. 

109.98 pounds of sugar. 



955.97 pounds total. 



342 



Ice; Cream Mixes 



Proof of Problem 33, Example 34 : 














Pounds 


Per Cent 




Fat 


M.S.N.F. 


Sugar 


T. S. 


Fat 


M.S.N.F. 


Sugar 


T. S 


Mix before 
standardizing 


10000.00 


780.00 


1260.00 


1300.00 




7.80 


12.60 


13.00 


33.40 




230.00 


92.13 


12.44 






40.00 


5.40 




45.40 












Condensed 


615.66 


3.08 


153.92 






.50 


25.00 




26.00 












Sugar 


126.39 






126 39 










100.00 


















Mix after 
standardizing 


10955.97 


875.21 


1426.36 


1426.39 


3727.96 


8.00 


13.00 


13.00 


34.00 



PROBLEM 34: HOW TO CALCULATE WHEN THE FAT IS OVER 

AND THE M. S. N. F. OR THE T. S. UNDER THE STANDARD 

DESIRED. ALSO WHEN THE PERCENTAGES OF FAT 

AND M. S. N. F. OR T. S. ARE OVER THE STANDARD 

DESIRED BUT WITH THE FAT IN A HIGHER 

RATIO THAN THE T. S. 

Skim-milk powder, sugar and water are to be added for 
standardizing. The calculation in problem 33, example 34, can be 
applied to the solution of this problem. However, after getting 
the M. S, N. F. in the proper ratio to the fat, water is to be added 
to bring the mix back to the standard desired. 
Solution of Problem 34, Based Upon Rule 29 : 
(1). Subtract the percentage of fat desired from the per- 
centage of fat in the mix, and multiply the remainder by the 
weight of the mix. Divide the result by the percentage of fat 
desired. The quotient equals the pounds of mix short. 

(2). Multiply the percentage of fat in the mix by the ratio 
of fat desired to M. S. N. F. desired, and from the result subtract 
the percentage of M. S. N. F. in the batch. Multiply the re- 
mainder by the number of pounds in the batch, and divide the 
product by the percentage of M. S. N. F. in the skim-milk powder. 
The quotient equals the number of' pounds of skim-milk powder 
required. 

(3). Multiply the pounds of mix short by the percentage of 
sugar desired. The product equals the pounds of sugar required. 
(4). The number of pounds of sugar required plus the number 
of pounds of skim-milk powder required subtracted from the 
number of pounds of mix short equals the number of pounds 
of water to add. 



Calculations 



343 



Solution Problem 34, Based Upon Formula 29a : 
(1). To calculate the pounds of mix short. 

(F— A)XM 

K= — ^ — 

(2). To calculate the pounds of skim-milk powder required. 

(FXR)— NXM] 



8^= 



S 



(3). To calculate the pounds of sugar required. 

U=KXV 
(4). To calculate the pounds of water required. 

W=M— (U— S^) 
Problem 34, Example 35 : 



Products 


Pounds 


Per Cent 


Fat 


M. S. N. F. 


Sugar 


T. S. 


Mix 


10,000 


8.24 


12.70 


13.00 


33.94 


Skim-milk powder 






95.00 




95.00 


Suear 


1,300 






100. 


100.00 






Composition desired 




8.00 


13.00 


13.00 


34.00 


Desired ratio of fat to M. S. N. F. is 1 to 1.625. 



Mix before standardizing contains .50 per cent of gelatin, 
which is included with the M. S. N. F. 

Solution of Problem 34, Example 35, Based Upon Rule 29 : 
(1). To calculate the pounds of mix short. 

8.24— 8.00=. 24, per cent of excess fat. 
10000 X. 0024=24, pounds of excess fat. 
24-^.08=300, pounds of mix short. 
(2). To calculate the pounds of skim-milk powder required. 
8.24X1.625=13.39, per cent of M. S. N. F. to equalize the 

fat in the batch. 
13.39— 12.70=. 69, per cent of M. S. N. F. short. 
10000X.0069=69, pounds of M. S. N. F. short. 
69-^-.95=72.63, pounds of milk powder required. 



344 



Ice Cream Mixes 



(3). To calculate the pounds of sugar required. 

300X-1300=r39, pounds of sugar required. 

(4). To calculate the pounds of water required. 

72.63--j-39=:111.63, pounds of sugar and milk poAvder. 
300 — 112=188, pounds of water required. 

Solution of Problem 34, Example 35, Based Upon Formula 29a ; 

(1). To calculate the pounds of mix short. 



(.0824— .0800) X 10000 
K= ^^ =300 



(2). To calculate the pounds of skim-milk powder required. 



[ (.0824X1.625)— .1270] XlOOOO 

Si=r ^ =72.63 

.95 



(3). To calculate the pounds of sugar required. 
U=300X. 13=39 

(4). To calculate the pounds of water required. 

W=300— (72.63+39) =188 



Proof of Problem 34, Example 35. 



Products 




Pounds 


Per Cent 




Fat 


M.S.N.F. 


Sugar 


T. S. 


Fat 


M.S.N.F. 


Su.?ar 


T. S. 


Mix 


10000.00 


824 


1270 


1300 


3394 


8.24 


12.70 


13.00 


33.94 


Skim-milk 
powder 


72.63 




69 




69 




95.00 




95.00 










39.00 






39 


39 






100.00 


100.00 














Water 


188 37 


































' 


Standardized 
product 


10300.00 


824 


1339 


1339 


3502 


8.00 


13.00 


13.00 


34.00 



Note: No account was taken of the small amount of fat in 
the skim-milk powder used. The addition of skim-milk powder 
is not practicable unless this can be added to the batch at 
pasteurizing temperatures. 



Fat and M. S. N. F. Over Standard 345 

PROBLEM 35: HOW TO CALCULATE WHEN THE PERCENTAGES 

OF FAT AND M. S. N. F. ARE BOTH OVER THE STANDARD 

DESIRED BUT WITH THE FAT IN A HIGHER RATIO 

THAN THE M. S. N. F. 

Skim-milk powder, sugar and water are to be added for 
standardizing. 

The calculation in problem 33, example 34, can be applied to 
the solution of this problem. However, after getting the M. S. 
N. F. in the proper ratio to the fat, water is to be added to bring 
the mix back to the standard desired. 

Solution of Problem 35, Based Upon Rule 30: 

(1). Subtract the percentage of fat desired from the per- 
centage of fat in the mix, and multiply the remainder by the 
pounds of mix. Divide the product by the percentage of fat 
desired in the mix and the result equals the pounds of mix short. 

(2). Multiply the percentage of fat in the batch by the ratio 
of fat to M. S. N. F., and subtract from the product the per- 
centage of M. S. N. F. in the batch. Multiply the remainder by 
the pounds in the batch and divide the product by the percentage 
of M. S. N. F. in the skim-milk powder. The quotient equals the 
pounds of skim-milk powder required, 

(3). Multiply the pounds of mix short by the percentage of 
sugar desired. The product equals the pounds of sugar required. 

(4). The pounds of sugar required plus the pounds of skim- 
milk powder required subtracted from the pounds of mix short 
equals the pounds of water required. 

Solution of Problem 35, Based Upon Formula 30 : 

(1). To calculate the pounds of mix short. 

(F— A)XM 

^= A 

(2). To calculate the pounds of skim-milk powder required. 

[(FXR)-N]XM 

^- S 

(3). To calculate the pounds of sugar required. 

U=KXV 
(4). To calculate the pounds of water required. 

W=K— (S^— U) 



346 Icp: Cream Mixes 

Problem 35, Example 35: 



Products 


Pounds 


Per Cent 


Fat 


M. S. N. F. 


Sugar 


T. S. 


Mix 


10,000 


8.30 


13.20 


13.00 


34.50 


Skim-milk powder 






95.00 




95.00 


Sugar 








100.00 


100.00 


Composition desired 




9.00 


13.00 


13.00 


34.00 


Desired ratio of fat to M. S. N. F. is 1 to 1.625. 



The mix before standardizing contains .50 per cent of gelatin 
which is included with the M. S. N. F. 

Solution of Problem 35, Example 36, Based Upon Rule 30. 
(1). To calculate the pounds of mix short. 

8.30 — 8.00=. 30, per cent of fat in excess. 

10000 X. 0030=30, pounds of fat in excess. 

30-^.08=375, pounds of mix short. 
(2). To calcTilate the pounds of skim-milk powder required. 

1.625X8.30=13.48, per cent of M. S. N. F. necessary to 
standardize the fat in the batch. 

13.48— 13.20=.28, per cent of M. S. N. F. short. 

.0028X10000=28, pounds of M. S. N. F. short. 

28-^.95^29.47, pounds of milk powder required. 
(3). To calculate the pounds of sugar required. 

375 X -1300=48.75, pounds of sugar required. 
(4). To calculate the pounds of water required. 

48.75-|-29.47=78.22, pounds of sugar and powder required. 

375 — 78.22=296, pounds of water required. 
Solution of Problem 35, Example 36, Based Upon Formula 30 : 
(1). To calculate the pounds of mix short. 
(. 083 X. 080) X 10000 

'^=- T8 =3'5 

(2). To calculate the pounds of skim-milk powder required. 

(.083X1.625)-.132] XlOOOO 



S^= 



.95 



:29.47 



Fat and M. S. N. F. Over Standard 



347 



(3). To calculate the pounds of sugar required. 

U=375X.1300=48.75 

(4). To calculate the pounds of water required. 

W=375— (29.47+48.75) r=296. 

Proof of Problem 35, Example 36. 



Products 




Pounds 


Per Cent 




Fat 


M.S.N.F. 


Sugar 


T.S. 


Fat 


M.S.N.F. 


Sugar 


T. S 


Mix 


10000,00 


830 


1320 


1300 


3450 


8.30 


13.20 


13.00 


34.50 


Skim-milk 
powder 


29.47 




28 




28 




95.00 




95 00 










Sugar 


48.75 






48.75 


48.75 






100.00 


100 00 














Water 


296.00 




































Standardized 
product 


10374.22 


830 


1348 


1348 


3526 


8.00 


13.00 


13.00 


34.00 



PROBLEM 36: HOW TO CACULATE WHEN THE PERCENTAGES 

OF FAT AND M. S. N. F. ARE BOTH OVER THE STANDARD 

DESIRED MAKING IT NECESSARY TO ADD SUGAR 

AND WATER ONLY. 

Solution of Problem 36, Based Upon Rule 31 : 

(1). Subtract the percentage of fat desired from the per- 
centage of fat in the mix and multiply the pounds of mix by the 
difference. Divide the product by the percentage of fat desired. 
The answer will be the pounds of mix short. 

(2). Multiply the pounds of mix short by the per cent of 
sugar desired. The answer will be the pounds of sugar required. 

(3). Subtract the pounds of sugar required from the pounds 
of mix short. The ansAver wil be the pounds of water required. 

Solution of Problem 36, Based Upon Formula 31 : 
(1). To calculate the pounds of mix short. 

(F— A) M 

K=^ — 

(2). To calculate the pounds of sugar to add. 

U=KXV 
(3). To calculate the pounds of water required. 

W=rK— U 



"348 Ice Cre;am Mixes 

Problem 36, Example 37 : 



Products 


Pounds 




Per Cent 




Fat 


M. S. N. F. 


Sugar 


T. S. 


Mix 


10,000 


8.20 


13.25 


13.00 


34.52 


Sugar 








100.00 


100.00 


Composition desired 




8.00 


13.00 


13.00 


34.00 



Solution of Problem 36, Example 37, Based Upon Rule 31: 

(1). To calculate the pounds of mix short. 

8.20 — 8.00=. 20, per cent of fat in excess. 

lOOOOX. 0020=20, pounds of fat in excess. 

20-^.08=: 250, pounds of mix short. 
(2). To calculate the pounds of sugar required. 

250X. 13=32. 50, pounds of sugar required. 
(3) . To calculate the pounds of water required. 

2.50 — 32.50=217.5, pounds of water required. 

Solution of Problem 36, Example 37, Based Upon Formula 31 : 
(1). To calculate the pounds of mix short. 

(.082— .080) X 10000 



J 1 



K= 



.08 



:250 



(2). To calculate the pounds of sugar to add. 

U=250X.13=32.50 
(3) . To calculate the pounds of water to add. 

W=250— 32.50=217.5 
Proof of Problem 36, Example 37: 



Products 




Pounds 


Per Cent 




Fat 


M.S.N.F. 


Sugar 


T. S. 


Fat 


M.S.N.F. 


Sugar 


T.S. 


Mix 


10000.00 


820 


1332.5 


1300 


3452.5 


8.20 


13.325 


13.00 


34.525 




32.50 






32.50 


32.5 






100.00 


100.00 














Water 


217.60 




































Standardized 
product 


10250.00 


820 


1332.5 


1332.5 


3485.0 


8.00 


13.00 


13.00 


34.00 



Sweetened Condensed Skim-Milk 349 

HOW TO CALCULATE WHEN USING SWEETENED CONDENSED 
SKIM-MILK IN ICE CREAM MIX. 

Sweetened condensed skim-milk can be used in the ice cream 
mix to furnish the entire sweetening necessary. The balance of 
the fat and M. S. N. F. can be made up by using cream or butter, 
and whole milk. Sweetened condensed skim-milk is an economi- 
cal substance to use. A good quality may be purchased from 
reliable firms and stored, and it will keep indefinitely. It also 
has the advantage of being very easy to use. It would un- 
doubtedly be used to a much greater extent than it is at present 
if manufacturers had formulas which would give good results 
when properly worked out. 

The method of calculation given herewith f.or using this prod- 
uct was originated largely by J. A. Cross. 

The average composition of sweetened condensed skim-milk 
is about 1.00 per cent fat, 28.00 per cent M. S. N. F. and 41.00 
per cent sugar. All of these values are subject to fluctuations 
so that the actual test of the product should be ascertained. 

In these calculations it is assumed that the M. S. N. F. in 
skim-milk serum is 8.90 per cent. This can be found exactly for 
any product by subtracting the percentage of fat in the product 
from 100 and dividing the percentage of M. S. N. F. by the 
remainder. 

Example: Whole milk tests 3.75 per cent fat, 8.60 per cent 
M. S. N. F. 

Solution : 

8.60 

=8.93, or per cent of M.S.N.F. in skim-milk serum. 



(100.00—3.75) 

The above problem is solved herewith by rule, formula, and 
example. A new set of factors differing from those previously 
used in this chapter, are used in the formulas. 

KEY TO FACTORS IN FORMULAS FOR USING SWEETENED 
CONDENSED SKIM-MILK. 

A=:The percentage of sugar desired. 

B=The percentage of sugar in the sweetened condensed skim- 
milk. 

C=The pounds of sweetened condensed skim-milk necessary 
to provide the sugar required. 



350 Ice Cream Mixes 

D=The percentage of M. S. N. F, in the sweetened condensed 
skim-milk. 

Er=The pounds of M. S. N. F. in the sweetened condensed 
skim-milk. 

F=The pounds of M. S. N. F. in the entire batch of mix. 

G=The average percentage of M. S. N. F. in skim-milk serum. 

H=:The pounds of skim-milk serum required. 

I r=:The pounds of fat required for the entire batch. 

J=The pounds of fat contained in the sweetened condensed 
skim-milk. 

K=The pounds of cream required. 

L=The percentage of fat in K. 

M=The percentage of fat in the whole milk. 

N=The percentage of fat in the butter. 

O^The pounds of butter required. 

prrzThe pounds of whole milk required. 

Q=The pounds of mix desired. 

R=rThe pounds of sugar required. 

S=:The percentage of M. S. N. F. desired. 

T=The percentage of fat required. 

U^The percentage of fat in sweetened condensed skim-milk. 

Problem 37. How to Calculate When Using Sweetened Con- 
densed Skim-milk in Ice Cream Mix. 

Solution of Problem 37, Based Upon Rule 32 : 

(1). To calculate the pounds of sweetened condensed milk 

necessary to furnish the sugar required. Multiply the pounds of 
mix desired by the percentage of sugar desired and divide by 
the percentage of sugar in the sweetened condnsed skim-milk. 
Call the answer A, or the pounds of sweetened condensed skim- 
milk required for the entire batch of mix to be made. 

(2). To calculate the pounds of skim-milk serum required. 

Multiply the pounds of mix desired by the percentage of M. S. 
N. F. desired, and subtract the answer from the pounds of 
M. S. N. F. in the sweetened condensed skim-milk required, 
found by multiplying the pounds of sweetened condensed skim- 
milk by the percentage of M. S. N. F. contained in the same. 
Call the remainder B, or the pounds of M. S. N. F. to be supplied 
by cream or whole milk. Divide B by 8.90 (the average M. S. 



Cai,cui,ations 351 

N. F. test of skim-milk serum), and call the answer C, or the 
pounds of skim-milk serum required. 

(3). To calculate the pounds of cream required and the per- 
centag-e of fat in the same. Multiply the pounds of mix desired, 
by the percentage of fat desired. Subtract from the answer the 
pounds of fat in the sweetened condensed skim-milk found by 
multiplying the pounds of sweetened condensed skim-milk re- 
quired by the percentage of fat in the same. Call the answer D, 
or the pounds of fat to be supplied by the cream. 

C-f-D=E, pounds of cream required. 

D-^E^Percentage of fat necessary in E, 
(4). To calculate the pounds of whole milk, cream, or butter 
to use. Subtract from the percentage of fat in E, the percentage 
of fat in the whole milk, and divide the remainder by the 
difference between the percentage of fat in the butter and the 
percentage of fat in the whole milk. Multiply the answer by E. 
Call the result F, or the pounds of butter required. E — F=:the 
pounds of whole milk required. 

Solution Problem 37 Based Upon Formula 32 : 
(1). To calculate the pounds of sweetened condensed skim- 
milk necessary to furnish the sugar required. 

QXA 

(2). To calculate the pounds of skim-milk serum required. 

(QXS)-(CXD) 
H_ ^ 

(3). To calculate the pounds of cream required. 

K=(QXT)— (CXU+H 
(4). To calculate the percentage of fat required in the cream. 
, (QXT)-(CXU) 

^= K 

(5). To calculate the pounds of whole milk and butter to use. 
^ (N— M) 
^"-^(L=MjX^ 

PrrzK— 



352 Ice Cream Mixes 

Problem 37, Example 38. 



Products 






Pounds 




Per Cent 






Fat 


M.S.N.F. 


Sugar 


T. S. 


Fat 


M.S.N.F. 


Sugar 


T. S. 


Whole milk 












3.50 


8.60 




12.00 


















Butter 












83.00 


1.50 




84.50 


















Sweetened 
condensed 












1.00 


28.00 


41.00 


70.00 


































88.00 






















Water 








































Pounds and 
composition 
of mix desired 


10,000 


800.00 


1250.0 


1300.0 


3400.00 


8.00 


12.50 


13.00 


34.00 



Solution of Problem 37, Example 38, Based Upon Rule 32. 

(1). To calculate the pounds of sweetened condensed skim- 
milk required. 

10000X-13=1300, pounds of sugar required. 
1300-^-.41=3171, pounds of sweetened condensed skim- 
milk required to furnish the sugar. 

(2). To calculate the pounds of skim-milk serum required. 

lOOOOX. 125=1250, pounds of M. S. N. F. required. 

3171 X. 28=887.9, pounds of M. S. N. F. in the sweetened 

condensed skim-milk. 
1250—887.9=362.10, pounds of M. S. N. F. to be supplied 

by the whole milk and the butter. 
362.10-^.089=^4069, pounds of skim-milk serum required. 

(3) . To calculate the pounds of cream required. 

lOOOOX .08=800, pounds of fat required. 

317lX.01=31.7, pounds of fat in the sweetened condensed 

skim-milk. 
800 — 31.7=768.3, pounds of fat to be supplied from whole 

milk and butter. 
4069+768.3=4837.3, pounds of cream required. 
768.3h-4837.3=15.88, per cent fat required in the cream. 

(4). To calculate the pounds of whole milk and butter to use. 

(.1588— .0350) 

TT^TTT^ — ^orox X4837=753.5, pounds of butter required. 
(.8300 — .0350) 

4837.3—753.5=4083.8, pounds of whole milk required. 



Calculations 



353 



Solution Problem 37, Example 38, Based Upon Formula 32 : 

(1). To calculate the pounds of sweetened condensed milk 
necessary to furnish the sugar required. 

10000X.13 



C: 



.41 



=3171 



(2). To calculate the pounds of M. S. N. F. required. 

(10000X.125)— (3171X.28) 
H= -^^ =4069 

(3). To calculate the pounds of cream required. 

K=(10000X.08)—(3171X-01) +4069^:4837.3 
(4). To calculate the percentage of fat required in the cream. 

(10000X.08)— (3171X.01) 



L=r 



=15.88 



4837.3 
(5). To calculate the pounds of whole milk and butter to use. 

(.1588— .0350) 

P=4837.3— 753.5=4083.8 
Proof Problem 37, Example 38. 



Products 


Pounds 


Per Cent 






Fat 


M.S.N.F. 


Sugar 


T. S. 


Fat 


M.S.N.F. 


Sugar 


T. S. 


Whole milk 


4083.8 


142.9 


351.1 




494.0 


3.50 


8.60 




12.10 










Butter 


753.5 


625,4 


11.3 




636.7 


83.00 


1.50 




84.50 










Sweetened 
condensed 
skim-milk 


3171 


31.7 


887.8 


1300.0 


2219.6 


1.00 


28.00 


41.00 


70.00 


Gelatin 


50.0 








44.0 








88.00 


















Water 


1942.7 




































Pounds and 
composition 
of mix ob- 
tained 


10000 


800.0 


1250.2 




3394.3 


8.00 


12.50 


13.00 


33.94 









In the above proof the percentage of T. S. is slightly lower 
than desired, due to water contained in gelatin, but close enough 
under usual conditions of manufacture. 



354 Ice Cream Mixks 

Recipe For Using Sweetened Condensed Skim-milk. 

Upon the basis of the above solution the following recipe can 
be used, the same being based upon 100 pounds of mix. 
48.4 pounds of cream testing 16.00 per cent fat. 
31.7 pounds of sweetened condensed skim-milk. 

.5 pounds of gelatin. 
19.4 pounds of water. 



100.0 pounds of total mix, testing 8.00 per cent fat; 12.50 
per cent M. S. N. F. ; 13.00 per cent sugar; .50 per cent 
gelatin ; and 34.00 per cent T. S. 
Whole milk, cream or butter of any composition can be sub- 
stituted for the cream testing 16.00 per cent of fat, by using the 
foregoing methods of calculation. 

Batches containing any desired number of gallons can be 
compounded upon the basis of the above recipe by multiplying 
the number of gallons desired by the pounds per gallon, and in 
turn the multiples of 100 pounds desired by the pounds given in 
the above recipe. 

HOW TO CALCULATE FROM TABLES THE AMOUNT OF 
SWEETENED CONDENSED SKIM-MILK TO USE. 

For the benefit of the ice cream maker mixing different sized 
batches, a great deal of calculation is eliminated and mistakes 
avoided by making out tables for his use, showing the exact 
number of pounds of each material necessary in all ordinary 
sizes of batches. The following tables may prove useful. They 
are in use in a number of factories, and give uniformly satis- 
factory results. The variations in fat tests of the different 
products cause some variation in the tests of finished products, 
but these may be easily adjusted by standardizing the finished 
mix. 

In Table 62 and 63 the gallons of ice cream mix desired are 
noted at the top, materials to be used at the side, and the pounds 
of each material necessary directly under the number of gallons. 
These tables and those given in Table 64 are calculated to 
produce an ice cream mix testing 8.00 per cent fat, 12.50 per 
cent M. S. N. F., .50 per cent gelatin, 13.00 per cent sugar and 



Recipes 



355 



-{4.00 per cent T. S. All products named have the same composi- 
tion as given under Problem 37, Example 38. 

TABLE 62. 
Table for making various gallons of ice cieam mix using sweetened 
condensed skim-milk and other products. Composition as named above. 



Products 


Total ni 


imber gallons of ice cream mix desired 










150 


200 


250 


300 


350 


400 


450 


500 


Whole milk 


lbs. 
544 


lbs. 
726 


lbs. 
907 


lbs. 
1090 


lbs. 
1270 


lbs. 
1450 


lbs. 
1625 


lbs. 
1815 


Butter 


11.3 


137 


171 


205 


240 


274 


308 


342 


Sweetened condensed skim-milk 


428 


560 


713 


856 


1000 


1140 


1283 


1426 


Gelatin 


6.7 


9 


11.2 


13.5 


15.7 


18 


20.2 


22 5 






Water 


265 


353 


441 


530 


618 


706 


794 


895 



In some cases whole milk is not always available in sufficient 
quantity. This is especially true in the south. In this case, 
skim-milk powder maj^ be used to make up the deficit, and the 
following formulas are used where skim-milk powder is employed. 

In Tables 63 and 64 just following, different proportions of 
skim-milk poAvder are used in each, thus making provision for 
varying amounts of whole milk that may be available. 

TABLE 63. 

Recipes for making various gallonages of ice cream mix, using sweetened 
condensed skim-milk and other products. Composition as named above. 



Products 


Total number of gallon 


s ice cream mix desired 




Lbs. 
150 


Lbs. 
200 


Lbs. 
250 


Lbs. 
300 


Lbs. 
350 


Lbs. 
400 


Lbs. 
450 


Lbs. 
500 


Whole milk 


384 


513 


640 


768 


896 


1025 


1153 


1280 






Butter 


107 


142 


178 


214 


249 


285 


320 


356 


Sweetened conden.sed skim-milk 


428 


560 


713 


856 


1000 


1140 


1283 


1426 


Gelatin 


6.7 


9 


11.2 


13.5 


15.7 


18 


20.2 


22.5 


Water 


408 


544 


680 


816 


952 


1090 


1223 


1360 


Skim-milk powder 


15 


20 


25 


30 


35 


40 


45 


50 



In case cream is to be made from other materials than butter 
and 3.50 per cent milk, figure 36.5 pounds of 20.7 per cent cream 
per 100 pounds of mix wanted. 



356 



Icp; Cre;am Mixes 

TABLE 64. 



Formulas for making various gallonages of ice cream mix using sweetened 
condensed skim-milk and other products. Composition as named above. 



Products 


Total number gallons 


ice cream mix 


desired 






150 


200 


250 


300 


350 


400 


450 


500 




Lbs. 


Lbs. 


Lbs. 


Lbs. 


Lbs. 


Lbs. 


Lbs. 


Lbs. 


Whole milk 


220 


294 


367 


440 


514 


587 


660 


734 






Butter 


112 


150 


187 


224 


262 


299 


337 


374 


Sweetened condensed skim-milk 


428 


560 


713 


856 


1000 


1140 


1283 


1426 


Gelatin 


6.7 


9 


11.2 


13.5 


15.7 


18 


20.2 


22.5 


Skim-milk powder 


30 


40 


50 


60 


70 


80 


90 


100 


Water 


550 


733 


917 


1100 


1284 


1466 


1650 


1832 







When cream is to be made from other material than butter 
and 3.5 per cent milk, figure 24.7 pounds of 30.5 per cent cream 
per 100 pounds of mix wanted. All of the above mixes have 
given very satisfactory results, and if properly made and homo- 
genized, any of them will produce 100 per cent overrun, and make 
a good, smooth and well flavored product. 

HOW TO STANDARDIZE ICE CREAM MIX BY MEANS OF TABLES 

BASED UPON USING BUTTER, WATER AND SKIM-MILK 

POWDER. 

To J. A. Cross belongs the credit for having developed a 
simple table method based upon using butter, water and skim- 
milk powder to effect standardization of ice cream mix. This 
method can be applied only when these products, and also a' 
homogenizer, or a viscolizer are available. Similar tables could 
be made covering other dairy products provided these would be of 
uniform composition. Butter and skim-milk powder of good 
quality are nearly constant in composition, readily available and 
can be conveniently carried in stock. For these reasons they 
have been selected as the most conveneint standardizing materials. 
In all of the tables the composition assumed is as follows : Butter 
83.00 per cent fat and 1.5 per cent S. N. F. ; skim-milk powder 
2.00 per cent fat, and 95.00 per cent S. N. F. Any small variations 
from these tests will not materially affect the accuracy of the 
tables. 



Table References 



357 



Composition of Mix for Which Tables are Given. — Tables of 
the above nature can be prepared for any composition of mix. 
Inasmuch as such a wide range of composition is possible it would 
be obviously impossible to give within the compass of this book 
tables to cover all possible compositions. The compositions given 
are those that have been found under actual use to yield the most 
satisfactory products, and cover a sufficiently wide range to suit 
all classes of trade. These are given in Table 65. 



TABLE 65. 

Composition of ice cream mix for which standardizing tables are given. 



No. 


Table 
No. 


Pages 
Where 
Found 


Per Cent 


of 

Mix. 


Fat 


M. S. N. F. 


Sugar 


Gelatin 


T. S. 


1 


67 


367-372 


8.00 


11.50 


13.00 


.50 


33.00 


2 


68 


373-378 


8.00 


12.50- 


13.00 


.50 


34.00 


4 


69 


379-384 


9.00 


11.50 


13.00 


.50 


34.00 


5 


70 


385-390 


10.00 


10.50 


14,00 


.50 


35.00 


6 


71 


391-396 


12.00 


8.50 


14.00 


.50 


35.00 


7 


72 


397-402 


12,00 


9.50 


14,00 


.50 


36.00 


8 


73 


403-408 


16.00 


7.50 


14,00 


.50 


38.00 


9 


74 


409-414 


18.00 


7.50 


14.00 


.50 


40,00 



Description of the Tables. — The tables given which are each in 
turn calculated upon the basis of the compositions given in 
Table 65 have a range in fat and S. N. F. as given in Table 66. 

The fat tests will be found upon the top and bottom lines of 
the tables. The S. N. F. tests upon the vertical line both to the 
right and to the left of the tables. At the intersection of the 
fat and S. N. F. columns corresponding to the tests of mix to be 
standardized, will be found the pounds of powder, water and 
butter necessary to standardize 1000 pounds of mix of that test. 
There are three spaces in each square and the figures indicating 
the pounds of butter, water and powder are in the following 
order ;— - 



358 



Ice Cream Mixes 



Top figure — Butter (Assumed to test 83.00 per cent fat and 
1.50 per cent S. N. F.). 

Center figure — Water. 

Bottom figure — Skim-milk powder (Assumed to test 2.00 
per cent fat and 95.00 per cent S. N. F.) 

The absence of figures in any space indicates that none of the 

omitted product is required. 

TABLE 66, 

Range of fat and S. N. F. in tables covering mixes of eight different 
compositions. 



No. 


Table 
No. 


Pages 
Where 
Found 


Per Cent 


Range of Fat 


Range of S. N. F. 


of 
iMix. 


Fat 


S. N. F. 


T. S. 


From 


To 


From 


To 


1 


67 


367-372 


8.00 


25.00 


33.00 


6.00 


10,00 


22,00 


28,00 


2 


68 


373-378 


8.00 


26.00 


34.00 


6.00 


10.00 


22,76 


29.25 


4 


69 


379-384 


9.00 


25.00 


34.00 


7.00 


11,00 


22,56 


27,45 


5 


70 


385-390 


10.00 


25.00 


35.00 


8.00 


12.00 


22,80 


27,20 


6 


71 


391-396 


12.00 


23.00 


35.00 


10,00 


14.00 


21.50 


24,50 


n 


72 


397-402 


12.00 


24.00 


36.00 


10.00 


14.00 


22.33 


25.66 


8 


73 


403-408 


16,00 


20.00 


38.00 


14.00 


18.00 


21.00 


23.00 


9 


74 


409-414 


18.00 


20.00 


38.00 


16,00 


20,00 


21,11 


22.89 



It is assumed that a definite percentage of sugar is always 
present in the mix that is to be standardized. In order to keep 
this percentage the same after standardizing, a definite percentage 
of sugar must be added to the batch along with the standardizing 
materials. The pounds of sugar to add is ascertained by the 
following formula : — 



C^ 



B^ 
'a^— B^ 



where 



Dkscription of Tables 35Q 

A^=100.00, or total percentages in mix 
B^^Pereentage sugar desired, 

C^=:The percentage of sugar to be added to the standard- 
izing materials. 

Solving the above formulas in the case of mixes containing 
13.00 and 14.00 per cent of sugar respectively we have. 

13.00 
^ ~ TftfTnn — iTon""'^^'^"^' °^ ^^^® percentage of sugar to be 

added to standardizing materials 
when mix with 13.00 per cent of 
sugar is desired. 

14.00 
^^~Tnn — II on =^^-28, or the percentage of sugar to be 
added to standardizing materials 

when mix with 14.00 per cent of 
sugar is desired. 

To obtain a mix after standardizing that contains the desired 
percentage of sugar, the total pounds of butter, water and skim- 
milk powder (or any one or more of these) must be multiplied 
by the factor C\ and the product, which will be the pounds of 
sugar required, must be added. 

Example: — Added in standardizing*: — 

10.00 pounds butter. 
75.00 pounds water. 
15.00 pounds skim-milk powder. 
100.00 pounds total. 

The per cent of sugar desired is 14.0. 
lOO.OOX-1628 per cent=16.28, pounds sugar desired. 
16.28-f-(100f 16.28) =14.00, per cent sugar desired after 
standardization. 

These tables are all based upon adding, when compounding the 
mix, the exact percentage of sugar called for in each of the 
compositions. 

How the Tables are Derived. — The successive steps involved in 
compiling the tables are the same regardless of the composition of 



360 Tc^ Cream Mixes 

mix desired. The various steps together with the principles of 
calculations involved are as follows : — 

(1). Determine the exact composition of mix desired. 

Example : — 

8.00 per cent fat. 

13.00 per cent sugar \ These three constituents are 

11.50 per cent M. S. N. P. i added together and called 
.50 per cent gelatin ' T. S. N. F. 

(2). Fill in percentages of fat progressively by .10 per cent 
from the lowest to the highest range desired. These should be 
placed in the horizontal spaces both at the top and at the bottom 
of the table. 

Calculate by ratio the percentages T. S. N. F. corresponding 
to the above two percentages of fat. Example : — 

8 : 12=6 : X, X=9.00, the per cent M. S. N. F. and 

gelatin in proportion with 6.00 per cent fat. 
9,00+13,00=22,00, the minimum per cent of T. S, N. F. 

Locate upon Table 67 at A 

and 8 : 12=10 : X, X=15,00, the per cent M, S. N, F, 
and gelatin in proportion with 10.00 per cent fat. 
15.00+13.00=28.00, the maximum per cent of T. S. N. F. 

Locate upon Table 67 at B 

Interpolate the T. S. N. F. in the vertical column from A to 
B, Each of the eight compositions of mix were compiled upon 
one large table. These in turn were divided into six sub-tables, 
each sub-table requiring one page. The letters referred to here- 
with appear only upon Table 67. 

(3). Determination of the composition of the products that 
are to be used in standardizing. Example : — 

Butter 83.00 per cent fat ; and 1.50 per cent S, N. F. 
Skim-milk powder 2.00 per cent fat, and 95.00 per cent 

S. N. F. 
Sugar 100.00 per cent T, S, 

(4). Calculate the percentage composition required upon 
each constituent used in standardizing in order that the resulting 
mixture after adding the sugar will be properly standardized. 



Examples 



361 



Example : — 
13.00 



100—13 



12.00 

sToo' 



.00 



87.00' 



nr: 14.94, the per cent of sugar to add to the other 
standardizing materials in standardizing 
to produce a mix containing 13.00 per 
cent of sugar. 

:13.79, the per cent of M. S. N. F. (including the 

gelatin) required in the standardizing mix- 
ture before adding the sugar. 

:9.20, the per cent of fat required in the standard- 



izing mixture before adding the sugar. 
(5). Calculate the available fat in theoretical mixture No. 1, 
and the available S. N. F. in theoretical mixture No. 2 using the 
methods of calculation given in problem 33 of this chapter. 

Example: — Theoretical mixture No. 1. 
Butter 1.50 81.21— Butter units 



13.79 



Skim-milk powder 95.00 12.19 — Skim-milk powder units. 

12.29+81.21rr:93.50, the sum of above units. 
81.21-^.9350=86.86, parts butter. 
12.29^.9350=13.14, parts skim-milk powder. 
86.86 parts butter=72.09 parts fat and 1.30 parts M. S. N. F. 
13.14 parts skim-milk powder=.26 parts fat and 12,49 
parts M. S. N. F. 
100.00 parts mixture No. 1=72.35 parts fat and 13.79 parts 
M. S. N. F. 
72.35—9.20=63.15, the per cent of fat in mixture No. 1 
available for standardizing. 
Example theoretical mixture No. 2. 
Butter 83.00 7.20 Butter units. 



9.20 



Skim-milk powder 2.00 



73.80 skim-milk powder 
units. 



362 



Ice Cream Mixes 



73.80+7.20=81.00, sum of units. 

7.20-:-.81=8.90, parts butter. 

73.80-^-.81r=91.10, parts skim-milk powder. 

8.90 parts butterr:r7.38 parts fat and .13 parts M. S. N. F, 

91.10 parts skim-milk powder=1.82 parts fat and 86.55 

parts M. S. N. F. 
100.00 parts mixture No. 2=9.20 parts fat and 86.68 parts 

M. S. N. F. 
86.68— 13.79=72.89, per cent S. N. F. in mixture No. 2 

available for standardizing. 

(6). Block off the square CDEF which includes that part of 
the table when the range is from the minimum under standard to 
standard in fat and likewise in T, S. N. F. 

Example: 6.00 to 8.00 per cent in fat and 22.80 to 25.00 in 
T. S. N. F. At the intersection C, both the fat and the T. S. N. F. 
are standard. 

Calculate the pounds of the two mixtures to use. 

Example : 

(.08— .06) X 1000 

^oTc =31.7 or pounds mixture No. 1 required. 

.8686X31.7 = 27.5. pounds of butter required. 
.1314X31.7:=4.2, pounds skim-milk powder required. 
Insert these values at E in table. 

(25.00— 22.00 )X 1000 

:=41.2 or pounds mixture No. 2 re- 
quired. 

.0890X41.2=3.7, pounds butter required. 
.9110X41.2=37.5, pounds skim-milk powder required. 
Insert these values at D in the table. 
To obtain value of F, add together E and D. 
Interpolate, either vertically or horizontally in the above 
square. 

(7.) Calculate the pounds of water required at the point G 
in the table. Example ; 
(.10— .08) X 1000 



72.89 



.08 



=250 



250— (250X.1300)=218 



CALCiTi^ATiNr, Tablks 363 

(8). Calculate the pounds of butter and water to use at the 
point H in the table. Example: — 

8 : 12— X : 1.50. X=:1,00, the per cent of fat required to 

equalize the S. N. F. in the butter. 
88.00—1.00=82.00, the per cent of fat in the butter avail- 
able for standardizing. 
(.1000— .0600) X 1000 



.82 
48.8X.015 



=48.8, the pounds of butter to use at H. 



^(218— 48.8) =175, the pounds of water to use at H. 



.1379 

(9). Calculate the pounds of water and powder to use at the 
point I in the table. Example : — 

8 : 12=2 : X. X=3.00, the per cent of S. N. F. required 
to equalize the fat in the skim-milk powder. 

95.00—3.00=92.00, the per cent of S. N. F. available for 
standardizing. 

(.28— .22) X 1000 

_ = 65.2, the pounds of skim-milk powder to use 

.92 

at point I. 

(65.2X.02) 
218-| TT^ 65.2=166, the pounds of water to use at I. 

(10). Calculate the pounds of water and skim-milk powder 
to use at Point J in the table. 

Example : — 

8 : 12=8.3 : X. X=12.45, the per cent of S. N. F. re- 
quired to equalize the percentage of fat at J, 
(.1245— .0920) X 1000 



.92 
powder to use at J. 
1000X.003 



:37.5, the pounds of skim-milk 



33, pounds of water to standardize 8.3 per 



.092 

cent fat. 

(37.5X.02) 

'^^H :rT7^ 37.5=2, pounds of water to use at J. 

,11do 



364 Ice; Cream Mixes 

(11). Calculate the pounds of water and butter to use at 
point K in the table. Example : — 

8 : 12=X : 11.33. X=8.3, the per cent of fat required to 

equalize the S. N. F. at K. 

(.083— .06) X 10000 
57c —27.1, the pounds of butter to use at K 

(27.1X.015) (11.33X.11) 
27.1 1 -— ^^ =14.0, the pounds of water 

to use at K. 

(12). Interpolate from I to G. 

Interpolate from E to K and K to H. 
Interpolate from D to J and J to I. 
Interpolate from H to G and G to I and complete the 
interpolation of entire table. 

Proof of the Accuracy of Tables. 

The tables have been all proved at the points corresponding 
to the above letters. Tables of any given composition derived 
as above described, and in which the interpolations have been 
properl}^ made should prove out at all points, and be correct for 
any combination of fat and T. S. 

How to apply the standardization tables in practice. 

1. About a half hour before a batch is to be homogenized, 
turn on the electric current upon the Mojonnier Tester, adjust 
the fat and solids ovens to the current temperatures, heat, cool 
and weigh a fat and a T. S. dish, and have everything in readi- 
ness for a rapid test. 

2. Before starting to homogenize the batch, see that all milk 
powder, butter, sugar, and gelatin are thoroughly dissolved, and 
that everything that is to be incorporated into the batch is in 
and mixed thoroughly. The accuracy of the entire system de- 
pends upon the accuracy of the first sample, and it must be a 
representative sample of the entire batch 

3. A few minutes after the homogenizer is started, obtain 
a sample from the cooling coils, and analyze for fat and T. S. 
If everything is in readiness, and the most efficient routine fol- 
lowed, this test may be completed in 30 minutes or less. (Record 
time 22 minutes.) 



SuccRssivR Steps 365 

4. Subtract the percentage of fat from the percentage of T. 
S. The result will be the percentage of T. S. N. F. 

5. Locate the most nearly corresponding fat and S. N. F. 
tests in the table based upon the composition desired. At the 
intersection will be found the pounds of butter, water or sugar 
necessary to add to 1000 pounds of mix of that test. Top space 
is for butter, center space for water, and lower space for skim- 
milk powder. 

6. Multiply the amounts indicated by the number of 
thousands of pounds of mix to be standardized. Example : If 
a batch of 2345 pounds is to be standardized, multiply in turn the 
amounts necessary for 1000 pounds by 2.345. The results will be 
the pounds of butter, water or skim-milk powder respectively 
necessary for the entire batch. 

7. Add together the total number of pounds of butter, water 
or sugar and multiply by the percentage of sugar required to 
produce a mix containing the desired percentage of sugar. Ex- 
ample : Mix desired to contain 13.00 per cent of sugar. There- 
fore add here sugar to the extent of 14.94 per cent of the total 
pounds of other products required for standardizing. 

The above tests and calculations are made while the batch is 
being homogenized, and can usually be completed before the 
entire batch has been run through. The standardizing materials 
can then be added to the last part of the batch, which has not 
yet been homogenized. When all has been run through and 
mixed in the holding tank, the fat and T. S. test should be 
standard. If skim-milk powder is necessary, it is usually advis- 
able to stop the homogenizer until it is thoroughly dissolved. 
Butter, sugar and water in small amounts can usually be mixed 
without stopping the machine. It is sometimes possible to mix 
the powder and the sugar with the water which is to be added 
if it is sufficient in amount, and it is a good practice to keep out 
about 10 gallons of the water until the batch has run through 
and then dump this in to wash out the mix remaining in the pipes. 

8. Obtain a sample of the standardized batch and analyze for 
fat and T. S. as a check upon the accuracy of the work. It 
should be accurate, within .1 of 1.00 per cent upon the fat, and 
within .20 of 1.00 per cent upon the T. S., of the standard desired. 



366 



Iciv Crkam Mixys 



These margins are liberal, and in practice as many as 50 consecu- 
tive batches have been run out with variation within .07 per cent 
upon the fat, and within .2 per cent upon the T. S. 

9. It is always simpler to standardize with butter and water 
only. These are easier to mix and to dissolve with the batch. 
By compounding the mix with an excess of M. S. N. F., the use 
of skim-milk powder can be reduced to a minimum, or entirely 
avoided. 



EXAMPLE AND PROOF OF ACCURACY OF STANDARDIZING 

TABLES. 

Example 39, taken from Table 67 showing quantity before 
standardizing materials added in standardizing, and proof. 







Pounds 


Per Cent 


Products 


Fat 


M.S.N. F. 
including 
Gelatin 


Sugar 


T. S. 


Fat 


M.S.N.P. 


Sugar 


T. S. 


Mix before 
standardzing 


1000.0 


73.0 


111.0 


130.0 


314.0 


7.30 


11.10 


13.00 


31.40 


Butter 


10.7 


8.9 


.1 




9.0 


83.00 


1.50 




84 50 










Water 








































Skim-milk 
powder 


12.7 


.3 


12.1 




12.4 


2.00 


95.00 




97.00 








Sugar 


3.5 






3.5 


3.5 






100.00 


100.00 












Total mix 
after stand- 
ardizing 


1026.9 


82.2 


123.2 


133.5 


338.9 


8.00 


12.00 


13.00 


33.00 



Example 40, taken from Table 67 
standardizing ; and materials added in 



showing quantity before 
standardizing, and proof. 







Pounds 


Per Cent 


Products 


Fat 


M.S.N.F. 
including 
Gelatin 


Sugar 


T. S. 


Fat 


M.S.N.F. 


Sugar 


T. S. 


Mi.x before 
standardizing 


1000.0 


91.0 


144.0 


130.0 


365.0 


9.10 


14.40 


13.00 


36.50 


Butter 


6.1 


5.1 


.1 




5.2 


83.00 


1.50 




84 50 










Water 


170.0 




































Skim-milk 
powder 












2.00 


95.00 




97.00 
















Sugar 


28.3 






26.3 


26.3 






100.00 


100.00 












Total mix 
after .stand- 
ardizing 


1202.4 


96.1 


144.1 


156.3 


396.5 


8.00 


12.00 


13.00 


33.00 



Compositions of Mixes 



367 



f S.00'5- Fat 
Standardizing | 11.507^ M. S N 
table for ice 1 13.007^ Sugar 
'ream mix | .-,o% Gelatin 

No. I testing: 

33.00% T. S. 



TABLE 67. 

Basis 1000 rounds of 

mi.\-. 
Top and bottom lines : 

Fat tests. 
Side columns: 

S. N. F. tests. 



In each square: 
Top figure: Pounds butter 
Center figure: Pounds water 
Bottom figure: Pounds skim-milk 
powder. 

(Blanks indicate none of kind required.) 




368 



Ice Cream Mixes 



TABLE 67 (Continued), 



standardizing 
table for ice 
cream mix 
No. I testing: 



8.00% Fat 
11.50% M. S. N. F. 
13.00% Sugar 
.50% Gelatin 



33.00% T. S. 



Basis 1000 pounds of 

ml.x. 
Top and bottom Unes: 

Fat tests. 
Side columns : 

S. N. F. tests. 



In each square : 

Top figure: Pounds butter. 

Center figure : Pounds water. 

Bottom figure: Pounds sklm-milk 
powder. 
(Blanks indicate none of kind required.) 





6 


6.1 


6 2 


6.3 


6.4 


6.5 


6.6 


6.7 


6.8 


6.9 


7 


7.1 


7.2 


7.3 




25.00 


27.5 
E 
4.2 


26.2 
4.0 


24.8 
3.8 


23.4 
3.6 


22.0 
3.4 


20.6 
3.2 


19.2 
2.9 


17.8 
2.7 


16.5 
2.5 


15.1 
2.3 


13.7 
2.1 


12.4 
1.9 


11.0 
1.7 


9.6 
1.5 


25.00 


25.15 


27.3 
2.2 


26.0 
2.0 


24.6 
1.8 


23.2 
1.6 


21.8 
1.4 


20.4 
1.2 


19.0 
1.0 


17.6 

.8 


16.3 
.6 


14.9 
.4 


13.5 

.2 


12.2 
1 


10.9 
2 


9.7 
3 


25.15 


25.30 


27.1 
K 
.3 


25.8 
.1 


24.4 
1 


23.2 
3 


22.0 
4 


20.7 
5 


19.5 
6 


18.3 

7 


17.1 

8 


15.9 
9 


14.6 
10 


13.4 
11 


12.2 
12 


10.9 
13 


25.30 


25.45 


28.1 
8 


26.8 
9 


25. 6 
10 


24.4 
11 


23.2 
12 


22.0 
14 


20. 7 
16 


19.5 
17 


18.3 
18 


17.1 
19 


15.9 
20 


14.6 
21 


13.4 
22 


12.2 
23 


25.45 


25.60 


29.3 
18 


28.1 
19 


26.8 
20 


25.6 
21 


24.4 
22 


23.2 
23 


22.0 
24 


20. 7 
25 


19.5 
26 


18.3 
27 


17.1 
29 


15.9 
31 


14.6 
32 


13.4 
33 


25.60 


25.75 


30.5 

28 


29.3 
29 


28.1 
30 


26.8 
31 


25.6 
32 


24.4 
33 


23.2 
34 


22.0 
35 


20.7 
36 


19.5 
37 


18.3 
38 


17.1 
40 


15.9 
41 


14.6 
43 


2S.7S 


25.90 


31.7 
38 


30.5 
39 


29.3 
40 


28.1 
41 


26.8 
42 


25.6 
43 


24.4 
44 


23.2 
45 


22.0 
46 


20. 7 
47 


19.5 
49 


18.3 
50 


17.1 
51 


15.9 
52 


25.90 


26.05 


32.9 

48 


31.7 
49 


30.5 
50 


29.3 
51 


28.1 
52 


26.8 
53 


2,5.6 
54 


24.4 
55 


23.2 
56 


22.0 
57 


20.7 

58 


19.5 
59 


18.3 
61 


17.1 
62 


26 05 


26.20 


34.2 

58 


32.9 
59 


31.7 
60 


30.5 
61 


29.3 
62 


28.1 
63 


26.8 
64 


25.6 
65 


24.4 
66 


23.2 
67 


22.0 
68 


20.7 
69 


19.5 
70 


18.3 
71 


26.20 


26.35 


35.4 
68 


34.2 
69 


32.9 
70 


31.7 
71 


30.5 
72 


29.3 
73 


28.1 
74 


26.8 
75 


25.6 
76 


24.4 

77 


23.2 

78 


22.0 

79 


20.7 
80 


19.5 

82 


26.35 


26 50 


36.6 

78 


35.4 
79 


34,2 
80 


32.9 
81 


31.7 
82 


30. 5 
83 


29.3 

85 


28.1 
86 


26.8 
87 


25.6 

88 


24.4 
89 


23.2 
90 


22.0 
91 


20.7 
92 


26.50 


26.65 


37.8 
88 


36.6 

89 


35.4 
90 


34.2 
91 


32.9 
92 


31.7 
93 


30.5 
94 


29.3 
95 


28.1 
96 


26.8 
97 


25.6 
98 


24.4 
100 


23.2 
101 


22.0 
102 


26.65 


26.80 


39.1 
98 


37.8 
99 


36.6 
100 


35.4 
101 


34.2 
102 


32.9 
103 


31.7 
104 


30.5 
105 


29.3 
106 


28.1 
107 


26.8 
108 


25.6 
109 


24.4 
111 


23.2 
112 


26.80 


26.95 


40.3 
108 


39.1 
109 


37.8 
110 


36.6 
111 


35.4 
112 


34.2 
113 


32.9 
114 


31.7 
115 


30.5 
116 


29.3 
117 


28.1 
118 


26.8 
119 


25.6 
120 


24.4 
121 


26.95 


27.10 


41.5 
118 


40.3 
119 


39.1 
120 


37.8 
121 


36.6 
122 


35.4 
123 


34.2 
124 


32.9 
125 


31.7 
126 


30.5 
127 


29.3 
128 


28.1 
129 


26.8 
131 


25.6 
132 


27.10 


27.25 


42.7 
128 


41.5 
129 


40.3 
130 


39.1 
131 


37.8 
132 


36.6 
133 


35.4 
134 


34.2 
135 


32.9 
136 


31.7 
137 


30.5 
138 


29.3 
139 


28.1 
140 


26.8 
142 


27.25 


27 40 


43.9 
138 


42.7 
139 


41.5 
140 


40.3 
141 


39.1 
142 


37.8 
143 


36.6 
144 


35.4 
145 


34.2 
146 


32.9 
147 


31.7 
148 


30.5 
149 


29.3 
151 


28.1 
152 


27.40 


27.55 


45.2 
148 


43.9 
149 


42.7 
150 


41.5 
151 


40.3 
152 


39.1 
153 


37.8 
154 


36.6 
155 


35.4 
156 


34.2 
157 


32.9 
158 


31.7 
159 


30.5 
160 


29.3 
161 


27.55 


27.70 


46.4 
158 


45.2 
159 


43.9 
160 


42.7 
161 


41.5 
162 


40.3 
163 


39.1 
164 


37.8 
165 


36.6 
166 


35.4 
167 


34.2 
168 


32.9 
169 


31.7 
170 


30.5 
171 


27.70 


27.85 


47.6 
168 


46.4 
168 


45.2 
170 


43.9 
171 


42.7 
172 


41.5 
173 


40.3 
174 


39.1 
175 


37.8 
176 


36.6 
177 


35.4 
178 


34.2 
179 


32.9 
180 


31.7 
181 


27.85 


B 
28 00 


48.8 

17£ 
H 


47. e 

ire 


46.4 
17- 


45.2 
178 


43.8 
I7f 


42.7 
180 


41. £ 
181 


40.3 

182 


39.1 

183 


37.8 
184 


36.6 

185 


35.4 

186 


34.2 
188 


32.9 
189 


28 00 




6 


6.1 


6.; 


6 : 


6.4 


6.£ 


6 < 


> 6.- 


6.f 


6.£ 


7.C 


7.1 


7.2 7.3 





Compositions of Mixes 



369 



TABLE 67 (Continued). 



Standardi2ing 
table for ice 
cream mix 
No. I testing: 



S.007c Fat 
11.50% M. S. N. F. 
13.007" Sucar 
.50% Gelatin 

33.00% T. S. 



Basts 1000 pounds of 

mix. 
Top and bottom lines : 

Fat tests. 
Side columns: 

S. N. F. tests. 



In each square: 

Top figure : Pounds butter. 

Center fiKure: Pounds water. 

Bottom figure: Pounds skim -mi lit 
powder. 
(Blanks Indicate none of kind reriilired.) 





7.4 


7.5 


7.( 


7.- 


7.8 


7,S 


8.C 


8.1 


8.2 


8.: 


8.4 


8.5 8.6 8.7 




22.0 


11. S 

38. S 


10.4 

38. S 


9.2 

38.3 


7.S 
38.1 


6.S 
37.9 


5.1 
37.7 


3.7 
D 

37.5 


2.3 
37.3 


37.1 


37. £ 


12 
39.1 


22 
40.7 


31 
42.4 


41 
44.0 


22 


22.15 


11.7 
37.0 


10.2 
36.7 


9.0 
36.5 


7.6 
36.3 


6.3 
36.1 


4.9 
35.9 


3.S 
35.7 


2.1 
35.5 


.7 
35.3 


4 
35. S 


13 

37.5 


23 
39.1 


32 
40.7 


42 
42.4 


22.15 


22.30 


11. S 
35.0 


10.0 
34.8 


8.S 
34.6 


7.4 
34.4 


6.1 
34.2 


4.7 
34.0 


3.3 
33.8 


1.9 
33.6 


.5 
33.4 


5 
34.2 


14 
35.8 


24 
37.5 


33 
39.1 


43 
40.7 


22.30 


22.45 


11.3 
33.2 


10.0 
32.9 


8.6 
32.7 


7.2 
32.5 


5.9 
32.3 


4.6 
32.1 


3.1 
31.9 


1.7 

31.7 


.3 
31.5 


7 
32.6 


16 
34.2 


26 
35.8 


35 
37.5 


45 
39.1 


22.45 


22.60 


U.l 
31.2 


9.9 
31.0 


8.4 
30.8 


7.0 
30. 6 


5.7 
30.4 


4.5 
30.2 


2.9 
30.0 


1.5 
29.8 


.1 
29.6 


8 
30.9 


17 
32.6 


27 
34.2 


36 
35.8 


46 
37.5 


22.60 


22.75 


11.0 
29.3 


9.7 
29.1 


8.2 
28.9 


6.8 

28.7 


5.5 
28.5 


4.2 

28..-? 


2.8 
28.1 


1.4 
27.9 


.0 
27.7 


9 
29.3 


18 
30.9 


28 
32.6 


37 
34.2 


47 
35.8 


22.75 


22.90 


10.8 
27.5 


9.5 
27.3 


8.0 
27.1 


6.7 
26.9 


5.3 
26.7 


4.0 
26.5 


2.6 
26.3 


1.2 
26.1 


1 
26.1 


10 

27.7 


18 
29.3 


29 
30.9 


38 
32.6 


48 
34.2 


22 90 


23.05 


10.6 
25.6 


9.3 
25.4 


7.8 
25.2 


6.5 
25.0 


5.1 

24.8 


3.8 
24.6 


2.4 
24.4 


1.0 
24.2 


3 
24.4 


11 
26.1 


19 
27.7 


30 
29.3 


39 
30.9 


49 
32.6 


23.05 


23.20 


10.5 
23.7 


9.1 
23.5 


7.7 
23.3 


6.3 
23.1 


5.0 
22.9 


3.6 

22.7 


2.2 
22.5 


.8 
22.3 


4 
22.8 


13 
29.4 


21 
26.1 


32 
27.7 


41 
29.3 


51 
30.9 


23.20 


23.35 


10.3 
21.9 


8.9 
21.6 


7.5 
21.4 


6.1 
21.2 


4.8 
21.0 


3.5 
20.8 


2.1 
20. 6 


.7 
20.4 


5 
21.2 


14 

22.8 


22 
24.4 


33 
26.1 


42 
27.7 


52 
29.3 


23.35 


23.50 


10.1 
20.0 


8.7 
19.8 


7.3 
19.6 


6.0 
19.4 


4.6 
19.2 


3.3 
19.0 


1.9 

18.8 


.5 
18.6 


6 
19.5 


15 
21.2 


23 

22.8 


34 
24.4 


43 
26.1 


53 

27.7 


23.50 


23,65 


9.8 
18.2 


8.6 
17.9 


7.1 

17.7 


5.8 
17.5 


4.4 
17.3 


3.1 

17.1 


1.7 
16.9 


.3 
16.7 


7 
17.9 


16 
19.5 


24 
21.2 


35 

22.8 


44 
24.4 


54 
26.1 


23.65 


23.80 


9.7 
16.2 


8.4 
16.0 


7.0 
15.8 


5.6 
15.6 


4.3 
15.4 


2.9 
15.2 


1.5 
15.0 


.1 

14.8 


9 
16.3 


18 
17.9 


26 
19.5 


37 
21.2 


46 
22.8 


56 
24.4 


23.80 
23.95 


23.95 


9.5 
14.3 


8.2 
14.1 


6.8 
13.9 


5.4 
13.7 


4.1 
13.5 


2.7 
13.3 


1.3 
13.1 


1 
13.0 


10 
14.7 


19 
16.3 


27 
17.9 


38 
19.5 


47 
21.2 


57 

22.8 


24.10 


9.3 
12.5 


8.0 
12.3 


6.6 
12.1 


5.2 
11.9 


3.9 
11.7 


2.5 
11.5 


1.1 
11.3 


2 
11.4 


11 
13.0 


20 
14.7 


28 
16.3 


39 
17.9 


48 
19.5 


58 
21.2 


24.10 


24.25 


9.1 
10.6 


7.8 
10.4 


6.5 
10.2 


5.0 
10.0 


3.7 
9.8 


2.4 
9.6 


1.0 
9.4 


4 
9.8 


13 
11.4 


22 
13.0 


30 
14.7 


41 
16.3 


50 
17.9 


60 
19.5 


24.25 


24.40 


9.0 

8.7 


7.7 
8.5 


6.3 
8.3 


4.8 
8.1 


3.5 
7.9 


2.2 

7.7 


.8 
7.5 


5 
8.2 


14 
9.8 


23 
11.4 


31 
13.0 


42 
14.7 


51 
16.3 


61 
17.9 


24.40 


24.55 


8.8 
6.8 


7.5 
6.6 


6.1 
6.4 


4.7 
6.2 


3.3 
6.0 


2.0 
5.8 


.6 
5.6 


6 
6.5 


16 

8.2 


25 
9.8 


33 
11.4 


44 
13.0 


53 
14.7 


63 
16.3 


24.55 


24.70 


8.6 
5.0 


7.3 

4.8 


5.9 
4.6 


4.5 
4.4 


3.2 
4.2 


1.8 
4.0 


.4 
3.8 


8 
4.9 


18 
6.5 


26 
8.2 


35 
9.8 


46 
11.4 


54 
13.0 


64 
14.7 


24.70 


24.85 


8.4 
3.1 


7.1 
2.9 


5.7 
2.7 


4.3 
2.5 


3.0 
2.3 


1.6 
2.1 


.2 
1.9 


9 
3.2 


19 
4.9 


28 
6.5 


37 

8.2 


47 
9.8 


55 
11.4 


65 
13.0 


24.85 




7.4 


7.5 


7.6 


7.7 


7.8 


7.9 


8.0 


8.1 


8.2 


8.3 


8.4 


8.5 


8.6 


8.7 





370 



Ice Cream Mixes 



TABLE 67 (Continued). 



standardizing 
table for ice 
cream mix 
No. I testing: 



S.00% Fat 
11.50'/r M. S. X. I*". 
13.00'7r Sugar 
.50'7r Gelatin 



33.00% T. S. 



Basis 1000 pounds of 

mix. 
Top and fiottom lines: 

Fat tests. 
Side rolumns: 

S. N. F. tests. 



In each square; 

Top figure ; Pounds butter. 

Center figure: Pounds water. 

Bottom figure: Pounds sliim-millt 
powder. 
(Blanks indicate none of kind required.) 





7.4 


7.5 


7.6 


7.7 


7 8 


7.9 


8.0 


8.1 


8.2 


8.3 


8.4 


8.5 


8.6 


8.7 




25.00 


8.2 
1.3 


6.9 
1.0 


5.5 
.8 


4.1 
.6 


2.8 
.4 


1.4 
.2 


Std. 
C 


10 
1.6 


20 
3.2 


29 
4.9 


39 
6.5 


49 

8.2 


57 
9.8 


66 
11.4 


25.00 


25.15 


8.5 
4 


7.3 
5 


6.1 
6 


4.8 
7 


3.6 

8 


2.4 

9 


1.2 
10 


11 


21 
1.6 


31 
3.2 


40 
4.9 


51 
6.5 


59 

8.2 


68 
9.8 


25.15 


25.30 


9.7 
14 


8.5 
15 


7.3 
16 


6.1 
17 


4.8 
18 


3.6 
19 


2.4 
20 


1.2 
21 


22 


32 
1.6 


42 
3.2 


52 
4.9 


61 
6.5 


61 
8.2 


25.30 


25.45 


10.9 
24 


9.7 
25 


8.5 
26 


7.3 
27 


6.1 

28 


4.8 
29 


3.6 
30 


2.4 
31 


1.2 
32 


33 


43 
1.6 


53 
3.2 


62 
4.9 


71 
6.5 


25.45 


25.60 


12.2 
34 


10.9 
35 


9.7 
36 


8.5 
37 


7.3 
38 


6.1 
39 


4.8 
40 


3.6 
41 


2.4 
42 


1.2 
43 


44 


54 
1.6 


64 
3.2 


72 
4.9 


25.60 


25.75 


13.4 

44 


12.2 
45 


10.9 
46 


9.7 
47 


8.5 
48 


7.3 
49 


6.1 
60 


4.8 
51 


3.6 
52 


2.4 
53 


1.2 
54 


55 


65 
1.6 


74 
3.2 


25.75 


25.90 


14.6 
53 


13.4 
54 


12.2 
55 


10.9 
57 


9.7 

58 


8.5 
59 


7.3 
60 


6.1 
61 


4.8 
62 


3.6 
63 


2.4 
64 


1.2 
65 


66 


75 
1.6 


25.90 


26.05 


15.9 
63 


14.6 
64 


13.4 
65 


12.2 
66 


10. 9 
67 


9.7 
68 


8.5 
69 


7.3 
70 


6.1 
71 


4.8 
72 


3.6 
73 


2.4 
74 


1.2 
75 


76 


26.05 


26.20 


17.1 
72 


15.9 
73 


14.6 
74 


13.4 

75 


12.2 

76 


10.9 

77 


9.7 

78 


8.5 
80 


7.3 
81 


6.1 

82 


4.8 
83 


3.6 
84 


2.4 
85 


1.2 

86 


26.20 


26.35 


18.3 
83 


17.1 

84 


15.9 
85 


14.6 
86 


13.4 

87 


12.2 

88 


10.9 
89 


9.7 
90 


8.5 
91 


7.3 
92 


6.1 
93 


4.8 
94 


3.6 
95 


2.4 
96 


26,35 


26.50 


19.5 
93 


18.3 
94 


17. 1 
95 


15.9 
96 


14.6 
97 


13.4 

98 


12 2 
99 


10.9 
100 


9.7 
101 


8.5 
102 


7.3 
103 


6.1 
104 


4.8 
105 


3.6 
106 


26.50 


26.65 


20- 7 
103 


19.5 
104 


18.3 
105 


17.1 
106 


15.9 
107 


14.6 
108 


13.4 
109 


12.2 

no 


10.9 
111 


9.7 
112 


8.5 
113 


7.3 
114 


6.1 
115 


4.8 
116 


26.65 


26.80 


22.0 
113 


20.7 
114 


19.5 
115 


18.3 
116 


17.1 
117 


15.9 
118 


14.6 
119 


13.4 
120 


12.2 
121 


10.9 
122 


9.7 
123 


8.5 
124 


7.3 
125 


6.1 
126 


26.80 


26.95 


23.2 
122 


22.0 
123 


20.7 
124 


19.5 
125 


18.3 
126 


17.1 
127 


15.9 
128 


14.6 
129 


13.4 
130 


12.2 
131 


10.9 
132 


9.7 
134 


8.5 
135 


7.3 
136 


26 95 


27.10 


24.4 
133 


23.2 
134 


22.0 
135 


20.7 
136 


19.5 
137 


18.3 
138 


17.1 
139 


15.9 
140 


14.6 
141 


13.4 

142 


12.2 
143 


10.9 
144 


9.7 
145 


8.5 
146 


27.10 


27.25 


25.6 
143 


24.4 
144 


23.2 
145 


22.0 
146 


20.7 
147 


19.5 
148 


18.3 
149 


17.1 
150 


15.9 
151 


14.6 
152 


13.4 
153 


12.2 
154 


10.9 
155 


9.7 
156 


27.25 


27.40 


26.8 
153 


25.6 
154 


24.4 
155 


23.2 
156 


22.0 
157 


20.7 
158 


19.5 
159 


18.3 
160 


17.1 
161 


15.9 
162 


14.6 
163 


13.4 
164 


12.2 
165 


10.9 
166 


27.40 


27.55 


28. 1 
162 


26.8 
163 


25.6 
164 


24.4 
165 


23.2 
166 


22.0 
167 


20.7 
168 


19.5 
169 


18.3 
170 


17.1 
171 


15.9 
172 


14.6 
173 


13.4 
174 


12.2 
175 


27.55 


27.70 


29.3 
172 


28.1 
173 


26.8 
174 


25.6 
175 


24.4 
176 


23.2 
177 


22.0 

178 


20.7 
179 


19.5 
ISO 


18.3 
181 


17.1 

182 


15.9 
183 


14.6 
184 


13.4 
185 


27.70 


27.85 


30.5 
182 


29 3 
183 

30.5 
191 


28.1 
184 


26.8 
185 


25.6 
186 


24.4 

187 


23.2 

188 


22.0 

189 


20.7 
190 


19.5 
191 


18.3 
192 


17.1 
193 


15.9 
194 


14.6 
195 


27.85 


28.00 


31.7 
190 


29.3 
192 


28.1 
193 


26.8 
194 


25.6 
195 


24.4 
196 


23.2 
197 


22.0 

198 

8.2 


20.7 
200 


19.5 
201 


18.3 
202 


17.1 
203 


15.9 
204 


28.00 




7.4 


7.5 


7.6 


7.7 7.8| 


7.9 


8.0 


8.1 


8.3 


8.4 


8.5 


8.6 


8.7 





Compositions of Mixrs 



371 



standardizing 
table for ice 
cream mix 
No. I testing: 



TABLE 67 (Continued). 



S.OO'^r Fat 

11.50% M. S. N. F. 

13.007? Sugar 

.50% Gelatin 



33.00% T. S. 



Uasis 1000 pounds of 

mix. 
Top iuul Ijottoni lines: 

Fat tests. 
Side rolumns: 

S. N. F. tests. 



In eacii square: 

Top figure: Pounds l)utter. 

Ceiiter figure: Poumls water. 

Bottom figure: Pounds sltlm-milk 
powder. 
{Blanks indicate none of kind re<iuired.) 





8.8 


8.9 


9 


9 I 


9.2 


9 3 


9 4 


9 5 


9.6 


9.7 


9.8 9.9 


10 




22 


50 
45.6 


60 
47.3 


70 
48.9 


79 
50.2 


89 
52.1 


99 
53.8 


108 
55.4 


118 
57.0 


127 
58.6 


137 
60.2 


147 
61.9 


157 
63.6 


I 

166 

65.2 


22 


22.15 


51 
44.0 


61 
45.6 


71 
47.3 


80 

48.9 


90 
50 2 


100 
52.1 


109 
53.8 


119 
55.4 


128 
57.0 


138 
58.6 


148 
60.2 


158 
61.9 


167 
63.6 


22.15 


22.30 


52 
42.4 


62 
44.0 


72 
45.6 


81 
47.3 


91 

48.9 


101 
50.2 


110 
52.1 


120 
53.8 


129 
55.4 


139 
57.0 


149 

58.6 


159 
60.2 


168 
61.9 


22,30 


22 45 


54 
40.7 


64 
42.4 


74 
44.0 


83 
45.6 


93 
47.3 


103 

48.9 


112 
50.2 


122 
52.1 


131 

53.8 


141 
55.4 


151 
57.0 


161 

58.6 


170 
60.2 


22.45 


22 60 


55 
39.1 


65 
40.7 


75 
42.4 


84 
44.0 


94 
45.6 


104 
47.3 


113 

48.9 


123 
50.2 


132 
52.1 


142 

53.8 


152 
55.4 


162 
57.0 


171 
58.6 


22 60 


22 75 


56 
37.5 


66 
39.1 


76 
40.7 


85 
42.4 


95 
44.0 


105 

45.6 


114 

47.3 


124 

48.9 


133 
50.2 


143 
52.1 


153 
53.8 


163 
55.4 


172 
57. 


22,75 


22 90 


57 

35.8 


67 
37.5 


77 
39.1 


86 
40.7 


96 
42.4 


106 
44 


115 
45.6 


125 
47.3 


134 
48.9 


144 
50.2 


154 
52.1 


164 
53.8 


173 
55.4 


22 90 


23 05 


58 
34.2 


68 
35.8 


79 
32.5 


88 
39.1 


98 
40.7 


108 
42.4 


117 
44.0 


127 
45.6 


136 

47.3 


146 

48.9 


156 
50.2 


166 
52.1 


175 
53.8 


23,05 


23 20 


60 
32.6 


70 
34.2 


80 
35.8 


89 
37.5 


99 
39.1 


109 
40.7 


118 

42.4 


128 
44.0 


137 
45.6 


147 
47.3 


157 
48.9 


167 
50.2 


176 
52.1 

178 
50,2 


23,20 


23 35 


61 
30.9 


71 
32.6 


81 
34.2 


90 
35.8 


100 
37.5 


110 
39.1 


119 
40.7 


129 
42.4 


138 
44.0 


148 
45.6 


158 
47.3 


168 
48.9 


23.35 


23.50 


62 
29.3 


72 
30.9 


82 
32.6 


91 
34.2 


101 
35.8 


111 
37.5 


120 
39.1 


130 
40.7 


139 
42.4 


149 
44.0 


159 
45.6 


169 
47.3 


178 
48.9 


23.50 


23 65 


63 

27.7 


73 
29.3 


83 
30.9 


92 
32.6 


102 
34.2 


112 
35.8 


121 
37.5 


131 
39.1 


140 
40.7 


150 
42.4 


160 
44.0 


170 
45.6 


180 
47.3 


23,65 


23.80 


65 
26.1 


75 
27.7 


85 
29.3 


94 
30 9 


104 
32.6 


114 
34.2 


123 

35.8 


132 
37.5 


142 
39.1 


152 
40.7 


162 
42.4 


172 
44.0 


182 
45.6 


23.80 


23 93 


66 
24.4 


76 
26.1 


86 
27.7 


95 
29.3 


105 
30.9 


115 
32.6 


124 
34.2 


133 
35.8 


143 
37.5 


153 
39.1 


163 
40.7 


173 
42.4 


183 
44.0 


23 9: 

24 10 


24 10 


67 

22.8 


77 
24.4 


87 
26.1 


96 
27.7 


106 
29.3 


116 
30.9 


125 
32.6 


134 
34.2 


144 
35.8 


153 
37.5 


164 
39.1 


174 
40.7 


184 
42.4 


24 25 


69 
21.2 


79 
22.8 


89 
24.4 


98 
26,1 


108 

27.7 


118 
29.3 


127 
30.9 


136 
32.6 


146 
34.2 


155 
35.8 


166 
37.5 


176 
39.1 


186 
40.7 


24. 2J 


24 40 


70 
19.5 


80 
21.2 


90 

22.8 


99 
24.4 


109 
26.1 


119 

27.7 


128 
29.3 


137 
30.9 


147 
32.6 


156 
34.2 


167 
35.8 


177 
37.5 


187 
39.1 


24 40 


24 55 


72 
17.9 


82 
19.5 


92 
21.2 


101 

22.8 


111 
24.4 


121 
26.1 


130 

27.7 


139 
29.3 


149 
30.9 


158 
32.6 


169 
34.2 


179 
35.8 


189 
37.5 


24 55 


24 70 


73 
16.3 


83 
17.9 


93 
19.5 


103 
21.2 


112 
22.8 


121 
24.4 


131 
26.1 


140 

27.7 


150 
29.3 


159 
30.9 


170 
32.6 


180 
34.2 


190 
35.8 


24 70 


24 85 


74 
14 7 


85 
16.3 


94 
17.9 


104 
19.5 


113 
21.2 


122 

22.8 


133 
24.4 


141 
26.1 


151 

27.7 


160 
29.3 


171 
30.9 


181 
32.6 


192 
34.2 


24 83 




8.8 


8.9 


9 


9.1 


9.2| 9.3 


9.4! 9.5 


9 6 


9 7 


9.8 


9.9 


10,0 





372 



Ice Cream Mixes 



TABLE 67 (Continued). 



standardizing 
table for ice 
cream mix 
No. I testing: 



8.00% Fat 
11.50% M. S. N. P. 
13.00%) Sugar 
L .50% Gelatin 



33.00% T. S. 



Basis 1000 pounds of 

mix. 
Top and bottom lines: 

Fat tests. 
Side columns : 

S. N. F. tests. 



In each square : 
Top figure: Pounds butter. 
Center figure: Founds water. 
Bottom figure: Pounds skim -milk 
powder. 

(Blanks indicate none of kind required.) 







8.8 


8.9 


9.0 


9.1 


9.2 


9.3 


9.4 


9.5 


9.6 


9.7 


9.8 


9.9 


10.0 






25.00 


76 
13.0 


86 
14.7 


95 
16.3 


105 
17.9 


114 
19.5 


122 
21.2 


134 
22.8 


143 
24.4 


152 
26.1 


161 

27.7 


173 
29.3 


183 
30.9 


193 
32.6 


25.00 




25.15 


77 
11.4 


88 
13.0 


97 
14.7 


106 
16.3 


116 
17.9 


123 
19.5 


136 
21.2 


144 

22.8 


153 
24.4 


162 
26.1 


175 

27.7 


185 
29.3 


194 
30.9 


25.15 




25 30 


79 
9.8 


89 
11.4 


98 
13.0 


108 
14.7 


117 
16.3 


125 
17.9 


137 
19.5 


145 
21.2 


154 
22.8 


163 
24.4 


176 
26.1 


186 
27.7 


196 
29.3 


25 30 




25.45 


80 
8.2 


90 
9.8 


100 
11.4 


109 
13.0 


119 
14.7 


127 
16.3 


138 
17.9 


147 
19.5 


155 
21.2 


165 

22.8 


178 
24.4 


188 
26.1 


197 

27.7 


25.45 




25.60 


82 
6.5 


92 

8.2 


101 

9.& 


111 
11.4 


120 
13.0 


128 
14.7 


140 
16.3 


149 
17.9 


157 
19.5 


167 
21.2 


180 

22.8 


189 
24.4 


198 
26.1 


25.60 




25.75 


83 
4.9 


94 
6.5 


103 

8.2 


113 

9.8 


122 
11.4 


130 
13.0 


142 
14.7 


150 
16.3 


159 
17.9 


168 
19.5 


181 
21.2 


189 
22.8 


199 
24.4 


25.75 




25.90 


85 
3.2 


95 
4.9 


104 
6.5 


114 

8.2 


123 
9.8 


131 
11.4 


143 
13.0 


151 
14.7 


160 
16.3 


169 
17.9 


182 
19.5 


189 
21.2 


200 

22.8 


25 90 




26.05 


86 
1.6 


96 
3.2 


105 
4.9 


115 
6.5 


125 

8.2 


133 
9.8 


144 
11.4 


153 
13.0 


162 
14.7 


170 
16.3 


184 
17.9 


190 
19.5 


201 
21.2 


26 OS 




26 20 


87 


97 
1.6 


107 
3.2 


116 
4.9 


126 
6.5 


135 

8.2 


145 

9.8 


154 
11.4 


164 
13.0 


172 
14.7 


186 
16.3 


192 
17.9 


203 
19.5 


26 20 




26.35 


1.2 
97 


98 


108 
1.6 


118 
3.2 


128 
4.9 


136 
6.5 


146 

8.2 


156 
9.8 


166 
11.4 


173 
13.0 


187 
14.7 


193 
16.3 


204 
17.9 


26 35 




26.50 


2.4 
107 


1.2 
108 


109 


119 
1.6 


129 
3.2 


138 
4.9 


148 
6.5 


157 

8.2 


167 

9.8 


175 
11.4 


188 
13.0 


195 
14.7 


205 
16.3 


26.50 




26 65 


3.6 
117 


2.4 
118 


1.2 
119 


120 


130 
1.6 


139 
3.2 


149 
4.9 


159 
6.5 


168 
8.2 


176 
9.8 


189 
11.4 


196 
13.0 


207 
14.7 


26.65 




26.80 


4.8 
127 


3.6 
128 


2.4 
129 


1.2 
130 


131 


141 
1.6 


151 
3.2 


160 
4.9 


170 
6.5 


179 

8.2 


190 

9.8 


198 
11.4 


208 
13.0 


26.80 




26.95 


6.1 
137 


4.8 
138 


3.6 
139 


2.4 
140 


1.2 
141 


142 


152 
1.6 


161 
3.2 


171 
4.9 


180 
6.5 


191 

8.2 


199 
9.8 


209 
11.4 


26.95 




27.10 


7.3 
147 


6.1 
148 


4.8 
149 


3.6 
150 


2.4 
151 


1.2 
152 


153 


162 
1.6 


173 
3.2 


181 
4.9 


192 
6.5 


201 

8.2 


211 

9.8 


27 10 




27.25 


8.5 
157 


7.3 
158 


6.1 
159 


4.8 
160 


3.6 
161 


2.4 
162 


1.2 
163 


164 


174 
1.6 


183 
3.2 


193 
4.9 


202 
6.5 


212 

8.2 


27.25 




27 40 


9.7 
167 


8.5 
168 


7.3 
169 


6.1 
170 


4.8 
171 


3.6 
172 


2.4 
173 


1.2 
174 


175 


184 
1.6 


194 
3.2 


204 
4.9 


213 
6.5 


27.40 




27.55 


10.9 
176 


9.7 
177 


8.5 
178 


7.3 
179 


6.1 
180 


4.8 
181 


3.6 
182 


2.4 
183 


1.2 
184 


185 


195 
1.6 


205 
3.2 


214 
4.9 


27.55 




27 70 


12.2 
186 


10.9 

187 


9.7 

188 


8.5 
189 


7.3 
190 


6.1 
191 


4.8 
192 


3.6 
193 


2.4 
194 


1.2 
195 


196 


206 
1.6 


216 
3.2 


27.70 




27.85 


13.4 
196 


12.2 
197 


10.9 
198 


9.7 
199 


8.5 
200 


7.3 
201 


6.1 
202 


4.8 
203 


3.6 
204 


2.4 
205 


1.2 
206 


207 


217 
1.6 


27.85 




28 00 


14.6 
20.5 


13.4 
206 


12.2 
207 


10.9 
208 


9.7 
209 


8.5 
210 


7.3 
212 


6.1 
213 


4.8 
214 


3.6 
215 


2.4 
216 


1.2 
217 


G 

218 


28 00 






8 8 


8.9 


9 


9 1 


9.2 


9 3 


9.4 


9.5 


9 6 


9.7 


9.8 


9 9 10.0 





Compositions of M 



ixEs 



373 



Standardi2ing 
table for ice 
cream mix 
No. 2 testing: 



8.00% Fat 
12.50% M. S. N. F 
13.00% Sugar 
50% Gelatin 

34.00% T. S. 



TABLE 68. 

Basis 1000 pounds of 
mix. 

Top and bottom lines- 

.Fat tests. 
Side columns : i 

S. N. F. tests. 



In each square: 

Top figure: Pounds butter. 

Center figure: Pounds water. 
I)owd\i °"''''' ^"""''s skim-mllk 
(Blanks indicate none of kind required. ) 




374 



Ice Cream Mixes 



TABLE 68 (Continued). 



standardizing 
table for i,( 
cream mix 
No. 2 testin 



r S.OOVr Fat 
J 12.50% M. S. N. 
I 13.00% Sut'ar 
I .50% Gelatin 

34.00% T. S. 



Basis 1000 pounds u 

mix. 
Top and bottom liiie.s 

Pat tests. 
Side columns: 

S. N. F. tests. 



In each square: 

Tojj figure; Pounds butter. 

Center figure: Pounds water. 

Bottom figure: Pounds skim-milk 
powder. 
(Blanks indicate none of kind required.) 





6 


6 1 


6 2 


6.3 


6 4 


6.5 


6.6 


6.7 

17.8 
.9 


6 8 


6 9 


7.0 


7 1 


7.2 


7 3 




26.16 


27.4 
2.5 


26.0 
2.3 


24.7 
2.1 


23.3 
1.8 


21.9 
1.6 


20.5 
1.4 


19.1 
1.2 


1G.4 
.7 


15.0 
.5 


13.6 
.3 


12.2 
.1 


10.8 
1 


9.7 
2 


26.16 


26.32 


27.2 

.4 


25.8 
.2 


24.4 
1 


23.1 
2 


21.9 
3 


20.7 
4 


19.5 
5 


18.3 
6 


17.1 

7 


15.8 
8 


14.6 
9 


13.4 
10 


12.2 
12 

13.4 
20 


11.0 
13 


26.32 


26.49 


28.0 

7 


26.8 

8 


25.6 
9 


24.4 
10 


23.1 
11 


21.9 
12 


20.7 
13 


19.5 
14 


18.3 
15 


17.1 
16 


15.8 
18 


14.6 
19 


12.2 
21 


26 49 


26.66 


29.2 
17 


28.0 

18 


26.8 
19 


25.6 
20 


24.4 
21 


23.1 
22 


21.9 
23 


20.7 

24 


19.5 
25 


18.3 

28 


17.1 
29 


15.8 
30 


14 6 
31 


13.4 
32 


26.66 


26 82 


30.5 
27 


29.2 

28 


28.0 
29 


26.8 
30 


25.6 
31 


24.4 
32 


23.1 
33 


21.9 
34 


20.7 
35 


19.5 
36 


18.3 
37 


17.1 
39 


15.8 
40 


14.6 
41 


26 82 


26.98 


31.7 
37 


30.5 
38 


29.2 
39 


28.0 
40 


26.8 
41 


25.6 

42 


24.4 
44 


23.1 
45 


21.9 
46 


20.7 

47 


19.5 

48 


18.3 
49 


17.1 
50 


15.8 
51 


26 98 


27.14 


32.8 
46 


31.7 
47 


30.5 

48 


29 2 

49 


28 
50 


26.8 
51 


25.6 
52 


24.4 
53 


23.1 
54 


21.9 
55 


20.7 
56 


19.5 

58 


18.3 
60 


17. 1 
61 


27.14 


27.30 


34.1 
56 


32.8 
57 


31.7 

58 


30.5 
59 


29.2 
61 


28.0 
62 


26.8 
63 


25.6 
64 


24.4 
65 


23.1 
66 


21.9 
67 


20.7 

68 


19.5 
69 


18.3 
71 


27.30 


27.47 


35.3 
66 


34.1 
67 


32.8 
68 


31.7 
69 


30 5 
70 


29.2 
71 


28.0 
72 


26.8 
73 


25.6 
75 


24.4 
76 


23.1 

77 


21.9 

78 


20.7 
79 


19.5 
80 


27.47 


27.62 


36.5 
76 


35.3 

77 


34.1 

78 


32.8 
79 


31.7 
80 


30.5 
81 


29.2 
83 


28.0 

84 


26.8 
85 


25.6 
86 


24.4 

87 


23.1 

88 


21.9 
89 


20.7 
90 


27.62 


27.78 


37.8 
85 


36.5 
86 


35.3 

87 


34.1 

88 


32.8 
89 


31.7 
90 


30.5 
91 


29.2 
92 


28.0 
93 


26.8 
95 


25.6 
97 


24.4 
98 


23.1 
99 


21.9 
100 


27.78 


27.94 


39.0 
95 


37.8 
96 


36.5 
97 


35.3 
98 


34.1 
99 


32.8 
100 


31.7 
101 


30.5 
102 


29 2 
103 


28.0 
105 


26.8 
106 


25.6 
107 


24.4 
108 


23.1 
110 


27.94 


28.10 


40.2 
105 


39.0 
106 


37.8 
107 


36.5 
108 


35.3 
109 


34.1 
111 


32.8 
112 


31.7 
114 


30.5 
115 


29.2 
116 


28 
117 


26.8 
118 


25.6 
119 


24.4 
120 


28 10 


28.27 


41.4 
115 


40.2 
116 


39.0 
117 


37.8 
118 


36.5 
119 


35.3 
120 


34.1 
121 


32.8 
122 


31.7 
123 


30.5 
124 


29.2 
126 


28 
127 


26.8 
128 


25.6 
129 


28.27 


28.43 


42.6 
125 


41.4 
126 


40.2 
127 


39.0 
128 


37.8 
129 


36.5 
130 


35.3 
131 


34.1 
132 


32.8 
133 


31.7 
134 


30.5 
136 


29.2 
137 


28.0 
138 


26 8 
139 


28.43 


28.60 


43.8 
135 


42.6 
136 


41.4 
137 


40.2 
138 


39 
139 


37.8 
140 


36.5 
141 


35.3 
142 


34.1 
143 


32.8 
144 


31.7 
145 


30.5 
146 


29.2 
147 


28.0 
148 


28.60 


28.76 


45.1 
145 


43.8 
146 


42.6 
147 


41.4 
148 


40 2 
149 


39.0 
150 


37.8 
151 


36.5 
152 


35.3 

154 


34.1 
155 


32.8 
156 


31.7 
157 


30.5 
158 


29.2 
159 


28.76 


28.93 


46.3 
154 


45.1 
155 


43.8 
156 


42.6 
157 


41.4 
158 


40.2 
159 


39.0 
160 


37.8 
161 


36.5 
162 


35.3 
163 


34.1 
164 


32.8 
165 


31.7 
166 


30 5 
167 


28.93 


29.09 


47.5 
164 


46.3 
165 


45.1 
166 


43.8 
167 


42.6 
168 


41.4 
169 


40.2 
170 


39.0 
172 


37.8 
173 


36.5 
174 


35.3 
175 


34.1 
176 


32.8 
177 


31.7 
178 


29.09 


29 25 


48.7 
174 


47.5 
175 


46.3 
170 


45, 1 
177 


43.8 

178 


42.6 
179 


41.4 
180 


40.2 

181 


39.0 

182 


37.8 
183 


36.5 
185 


35.3 
186 


34.1 

187 


32.8 

188 


29 25 




6 


6 1 


6 2 


6.3 


6.4 


6 5 


6 6 


6 7 


6 8 


6 9 


7 


7 1 


7 2 


7 3 





Compositions of Mixes 



375 



TABLE 68 (Continued). 



standardizing 
table for ice 
cream mix 
No. 2 testing: 



S.OOr^ Fat 
12.50% M. S. N. 
13.00% Sugar 
L ..iO% Gelatin 



34.00% T. 8. 



Basis 1000 poumls of 

mi.K. 
Top and bottom lines: 

Fat tests. 
Side columns: 

S. N. F. tests. 



In each s(iuare: 

Top figure: Pounds butter. 

Center figure: Pounds water. 

Bottom figure: Pounds skim-milk 
powder. 
(Blanks indicate none of kind renuired. 





7.4 


7.5 


7.6 


7.7 


7.8 


7.9 


8.0 


8.1 


8.2 


8.3 


8.4 


8.5 


8.6 


8.7 




22.76 


12.3 
42.5 


10.9 
42.3 


9.5 
42.1 


8.1 
41.9 


6.7 
41.6 


5.4 
41.4 


4.0 
41.2 


2.6 
41.0 


1.2 
39.8 


1 
40.7 


10 
42.5 


20 
44.3 


29 
46.0 


39 
47.8 


22.76 


22.92 


12.1 
40.5 


10.7 
40.2 


9.3 
40.0 


7.9 
39.8 


6.5 
39.5 


5.2 
39.3 


3.8 
39.1 


2.4 
38.9 


1.0 
38.7 


2 
38.9 


11 
40.7 


21 
42.5 


30 
44.3 


40 
46.0 


22.92 


23.08 


11.9 

38.4 


10.5 

38.2 


9.1 
37.9 


7.7 
37.7 


6.3 
37.5 


5.0 
37.3 


3.6 
37.1 


2.2 
36.9 


.8 
36.7 


4 
37.2 


13 

38.9 


23 
40.7 


32 
42.5 


42 
44.3 


23.08 


23.24 


11.7 
36.4 


10.3 
36.2 


8.9 
36.0 


7.5 
35.7 


6.1 
35.4 


4.8 
35.2 


3.4 
35.0 


2.0 
34.8 


.6 
34.5 


5 
35.4 


14 

37.2 


24 
38.9 


33 
40.7 


43 
42.5 


23.24 


23.41 


11.5 
34.4 


10.1 
34.2 


8.7 
33.9 


7.3 
33.7 


5.9 
33.5 


4.6 
33.2 


3.2 
33.0 


1.8 
32.8 


.4 
32.6 


7 
33.6 


16 
35.4 


26 
37.2 


35 
38.9 


45 
40.7 


23.41 


23.57 


11.3 
32.1 


9.9 
31.9 


8.5 
31.7 


7.1 
31.5 


5.7 
31.3 


4.4 
31.1 


3.0 
30.9 


1.6 
30.7 


.2 
30.5 


8 
31.9 


17 
33.6 


27 
35.4 


36 
37.2 


46 
38.9 


23.57 
23.73 


23.73 


11.1 
30.3 


9.7 
30.0 


8.3 
29.7 


6.9 
29.5 


5.5 
29.3 


4.2 
29.1 


2.8 
28.9 


1.4 

28.7 


.0 

28.5 


9 
30.1 


18 
31.9 


28 
33.6 


37 
35.4 

39 
33.6 


47 
37.2 


23.89 


10.9 
28.1 


9.5 
27.9 


8.1 
27.7 


6.7 
27.5 


5.3 
27.2 


4.0 
27.0 


2.6 
26.8 


1.2 
26.6 


1 
26.4 


11 
28.3 


20 
30.1 


30 
31.9 


49 
35.4 


23.89 


24.06 


10.7 
26.0 


9.3 
25.8 


7.9 
25.6 


6.5 
25.3 


5.1 
25.1 


3.8 
24.9 


2.4 
24.7 


1.0 
24.5 


2 

24.8 


12 
26.6 


21 
28.3 


31 
30.1 


40 
31.9 


50 
33.6 


24.06 


24.22 


10.5 
24.0 


9.1 
23.7 


7.7 
23.5 


6.3 
23.3 


4.9 
23.1 


3.6 
22.9 


2.2 
22.7 


.8 
22.5 


4 
23.0 


14 

24.8 


23 
26.6 


33 

28.3 


42 
30.1 


52 
31.9 


24.22 


24.38 


10.3 
21.9 


8.9 
21.7 


7.5 
21.5 


6.1 
21.3 


4.7 
21.1 


3.4 
20.8 


2.0 
20.6 


.6 
20.4 


5 
21.2 


15 
23.0 


24 
24.8 


34 
26.6 


43 
28.3 


53 
30.1 


24.38 


24.54 


10.1 
19.8 


8.7 
19.6 


7.3 
19.4 


5.9 
19.2 


4.5 
18.9 


3.2 

18.7 


1.8 
18.5 


.4 
18.3 


6 
19.5 


16 
21.2 


25 
23.0 


35 

24.8 


44 
26.6 


54 
28.3 


24.54 


24.70 


9.9 
17.9 


8.5 
17.7 


7.1 
17.4 


5.7 
17.2 


4.3 
17.0 


3.0 
16.7 


1.6 
16.5 


.2 
16.3 


8 
17.7 


18 
19.5 


27 
21.2 


37 
23.0 


46 
24.8 


56 
26.6 

57 

24.8 


24.70 


24.86 


9.7 
15.7 


8.3 
15.5 


6.9 
15.3 


5.5 
15.1 


4.1 
14.8 


2.8 
14.6 


1.4 
14.4 


.0 
14.2 


9 
15.9 


19 
17.7 


28 
19.5 


38 
21.2 


47 
23.0 


24.86 


25.03 


9.5 
13.8 


8.1 
13.5 


6.7 
13.3 


5.3 
13.1 


3.9 
12.8 


2.6 
12.6 


1.2 
12.4 


1 
12.4 


11 
14.2 


21 

15.9 


30 
17.7 


40 
19.5 


49 
21.2 


59 
23.0 


25.03 


25.19 


9.3 
11.6 


7.9 
11.3 


6.5 
11.1 


5.1 
10.9 


3.7 
10.6 


2.4 
10.4 


1.0 
10.2 


2 
10.6 


12 
12.4 


22 
14.2 


31 
15.9 


41 
17.7 


50 
19.5 


60 
21.2 


25.19 


25.35 


9.1 
9.6 


7.7 
9.3 


6.3 
9.1 


4.9 
8.9 


3.5 

8.6 


2.2 
8.4 


.8 
8.2 


3 

8.9 


13 
10.6 


23 
12.4 


32 
14.2 


42 
15.9 


51 
17.7 


61 
19.5 


25.35 


25.51 


8.9 
7.5 


7.5 
7.2 


6.1 
7.0 


4.7 
6.8 


3.3 

6.5 


2.0 
6.3 


.6 
6.1 


6 
7.1 


15 
8.9 


25 
10.6 


34 
12.4 


44 
14.2 


53 
15.9 


63 
17.7 


25.51 


25.68 


8.7 
5.5 


7.3 
5.2 


5.9 
5.0 


4.5 

4.8 


3.1 
4.5 


1.6 
4.3 


.4 
4.0 


7 
5.3 


16 
7.1 


26 
8.9 


35 
10.6 


45 
12.4 


54 
14.2 


64 
15.9 


25.68 


25.84 


8.5 
3.4 


7.1 
3.1 


5.7 
2.9 


4.3 
2.6 


2.9 

2.4 


1.6 
2.2 


.2 
2.0 


9 
3.5 


18 
5.3 


28 
7.1 


37 
8.9 


47 
10.6 


56 
12.4 


66 
14.2 


25.84 


26 00 


8.3 
1.4 


6.9 
1.1 


5.5 

.9 


4.1 

.6 


2.7 
.4 


1.3 

.2 


Stop 


10 
1.8 


19 
3.5 


29 
5.3 


38 
7.1 


48 
8.9 


57 
10.6 


67 
12.4 


26.00 




7.4 


7.5 


7.6 


7.7 


7.8 


7.9 


8.0 


8.1 


8.2 


8.3 


8.4 


8.5 


8.6 


8.7 





376 



Ice Cream Mixes 



TABLE 68 (Continued), 



r S.007f Fat 
Standardizing I 12.50% M. S. N. 
table for ice | 13.00% Sugar 
cream mix | ..50% Gelatin 

No. 2 testing: 

34.00% T. S. 



Basis 1000 pounds of 

mix. 
Top and bottom lines : 

Fat tests. 
Side columns: 

S. N. F. tests. 



In each square: 

Top figure: Pounds butter. 

Center figure: Pounds water. 

Bottom figure: Pounds skim-milk 
powder. 
(Blanks indicate none of kind required.) 





7.4 


7.5 


7.6 


7.7 


7.8 


7 9 


8.0 


8.1 


8.2 


8.3 


8.4 


8.5 


8.6 


8.7 




26.16 


8.5 
3 


7.3 
5 


6.1 

6 


4.9 
7 


3.7 

S 


2.4 
9 


1.2 
10 


11 


20 
1.8 


30 
3.5 


39 
5.3 


49 
7.1 


58 
8.9 


68 
10.6 


26.16 


26 32 


9.7 
14 


8.5 
15 


7.3 
16 


6.1 
17 


4.9 
18 


3.7 
19 


2.4 
20 


1.2 
21 


22 


32 
1.8 


41 
3.5 


51 
5.3 


60 
7.1 


70 

8.9 


26.32 


26.49 


11.0 
22 


9.7 
25 


8.5 
26 


7.3 
27 


6.1 

28 


4.9 
29 


3.7 
30 


2.4 
31 


1.2 
32 


33 


42 
1.8 


52 
3.5 


61 
5.3 


71 
7.1 


26.49 


26 66 


12.2 
33 


no 

34 


9.7 
35 


8.5 
37 


7.3 
38 


6.1 
39 


4.9 
40 


3.7 
41 


2.4 
42 


1.2 
43 


44 


54 
1.8 


63 
3.5 


73 
5.3 


26 66 


26.82 


13.4 
42 


12.2 
44 


11.0 
45 


9.7 
46 


8.5 
48 


7.3 
49 


fi.l 
50 


4.9 
51 


3.7 
52 


2.4 
53 


1.2 
54 


55 


64 
1.8 


74 
3.5 


26.82 


26.98 


14.6 
S2 


13.4 
54 


12.2 
55 


11.0 
56 


9.7 
57 


8.5 
58 


7.3 
59 


6.1 
60 


4.9 
61 


3.7 
62 


2.4 
63 


1.2 
64 


65 


75 
1.8 


26 98 


27.14 


15.8 
62 


14.6 
63 


13.4 
64 


12.2 
66 


11.0 
67 


9.7 
68 


8.5 
69 


7.3 
70 


6.1 
71 


4.9 
72 


3.7 
73 


2.4 
74 


1.2 
75 


76 


27 14 


27.30 


17.1 
72 


15.8 
73 


14.6 

74 


13.4 
75 


12.2 

77 


11.0 

78 


9.7 
79 


8.5 
80 


7.3 

81 


6.1 

82 


4.9 
83 


3.7 
84 


2.4 
85 


1.2 
86 


27.30 


27.47 


18.3 

82 


17.1 
83 


15.8 
84 


14.6 
85 


13.4 
86 


12.2 

87 


11.0 

88 


9.7 
89 


8.5 
90 


7.3 
91 


6.1 
93 


4.9 
94 


3.7 
95 


2.4 
96 


27.47 


27.62 


19.5 
92 


18.3 
9.3 


17.1 

94 


15.8 
95 


14.6 
96 


13.4 

97 


12.2 
98 


11.0 

99 


9.7 
101 


8.5 
102 


7.3 
103 


6.1 
104 


4.9 
105 


3.7 
106 


27.62 


27.78 


20.7 
101 


19.5 
102 


IS. 3 
103 


17.1 
104 


15.8 
105 


14.6 
106 


13.4 
108 


12.2 
109 


110 
110 


9.7 
111 


8.5 
112 


7.3 
113 


6.1 
114 


4.9 
115 


27.78 


27.94 


21.9 
112 


20.7 
113 


19.5 
114 


18.3 
115 


17.1 
116 


15.8 
117 


14.6 
118 


13.4 
119 


12.2 
120 


11.0 
122 


9.7 
123 


8.5 
124 


7.3 
125 


6.1 
126 


27 94 


28 10 


23.1 
121 


21.9 
122 


20.7 
124 


19.5 
125 


18.3 
126 


17.1 
127 


15.8 
128 


14.6 
129 


13.4 
131 


12.2 
132 


11.0 
133 


9.7 
134 


8.5 
135 


7.3 
136 


28 10 


28.27 


24.4 
130 


23.1 
131 


21.9 
132 


20.7 
134 


19.5 
135 


18.3 
136 


17.1 
137 


15.8 
138 


14.6 
140 


13.4 
141 


12.2 
142 


11.0 
14:^ 


9.7 
145 


8.5 
146 


28 27 


28.43 
28.60 


25.6 
140 


24.4 
141 


23.1 
142 


21.9 
143 


20.7 
144 


19.5 
146 


18.3 
147 


17.1 

148 


15.8 
149 


14.6 
150 


13.4 
151 


12.2 
152 


11.0 
153 


9.7 
154 


28.43 


26.8 
150 


25.6 
151 


24.4 
153 


23.1 
154 


21.9 
155 


20.7 
150 


19.5 
157 


18.3 
158 


17.1 
159 


15.8 
160 


14.6 
162 


13.4 
163 


12.2 
164 


11.0 
165 


28.60 


28.76 


28.0 
160 


26.8 
161 


25.6 
162 


24.4 
164 


23.1 
165 


21 .9 
166 


20.7 
167 


19.5 
168 


18.3 
169 


17.1 
170 


15.8 
171 


14.6 
172 


13.4 
174 


12.2 
175 


28.76 
28.93 


28.93 


29.2 
168 


28.6 
169 


26.8 
170 


25.6 
171 


24.4 
173 


23.1 
174 


21.9 
175 


20.7 
176 


19.5 
177 


18.3 
179 


17.1 
180 


15.8 
181 


14.6 
182 


13.4 
183 


29.09 


30.5 
179 


29.2 
180 


28.0 
181 


26.8 
183 


25.6 
184 


24.4 
185 


23.1 
186 


21.9 
187 


20.7 

188 


19.5 
189 


18.3 
190 


17.1 
191 


15.8 
192 


14.6 
194 


29 09 


29.25 


31.7 
189 


30.5 
190 


29.2 
191 


28.0 
192 


26.8 
193 


25.6 
194 


24.4 
195 


23.1 

197 


21.9 

198 


20.7 
199 


19.5 
200 


18.3 
201 


17 1 
202 


15.8 
203 


29.25 




7.4 


7.5 


7.6 


7.7 


7.8 


7.9 


8.0 


8 1 


8.2 


8.3 


8.4 


8.5 


8.6 


8.7 





Compositions of Mixes 



377 



TABLE 68 (Continued). 



standardizing 
table for ice 
cream mix 
No. 2 testing: 



r 8.00% Fat 
■ 12.50% M. S. N. F. 
13.00% Sugar 
.50% GelaUn 



34.00% T. S. 



Basis 1000 pounds of 

mix. 
Top and bottom lines : 

Fat tests. 
Side coiumns: 

S. N. F. tests. 



In eadi square: 

Top figure: Pounds butter. 

Center figure: Pounds water. 

Bottom figure: Pounds slcim-milis 
powder. 
(Bianl;s indicate none of l<ind required. 





8.8 


8.9 


9.0 


9.1 


9.2 


9.3 


9.4 


9.5 


9 6 


9.7 


9.8 


9 9 


10 




22.76 


48 
49.6 


58 
51.3 


67 
53.1 


77 
54.9 


86 
56.7 


96 
58.4 


105 
60.2 


115 
62.0 


124 
63.7 


134 
65.5 


143 
67.3 


153 
69.0 


162 
70.8 


22.76 


22 92 


49 

47.8 


59 
49.6 


68 
51.3 


78 
53.1 


87 
54.9 


97 
56.7 


106 
58.4 


116 
60.2 


125 
62.0 


135 

63.7 


144 
65.5 


154 
67.3 


163 
69.0 


22.92 


23.08 


51 
46.0 


61 

47.8 


70 
49.6 


80 
51.3 


89 
53.1 


99 
54.9 


108 
56.7 


118 
58.4 


127 
60.2 


137 
62.0 


146 
63.7 


156 
65.5 


165 
67.3 


23 08 


23 24 


52 
44.3 


62 
46.0 


71 
47.6 


81 
49.6 


90 
51.3 


100 
53.1 


109 
54.9 


119 
56.7 


128 

58.4 


138 
60.2 


147 
62.0 


157 
63.7 


166 
65.5 


23 24 


23 41 


54 
42.5 


64 
44.3 


73 
46.0 


83 

47.8 


92 
49.6 


102 
51.3 


111 
53.1 


121 
54.9 


130 

56.7 


140 

58.4 


149 
60.2 


159 
62.0 


168 
63.7 


23.41 


23.57 


55 
40.7 


65 
42.5 


74 
44.3 


84 
46.0 


93 

47.8 


103 
49.6 


112 
51.3 


122 
53.1 


131 
54.9 


141 
56.7 


150 

58.4 


160 
60.2 


169 
62.0 


23 57 


23.73 


56 
38.9 


66 
40.7 


75 
42.5 


85 
44.3 


94 
46.0 


104 

47.8 


113 
49.6 


123 
51.3 


132 
53.1 


142 
54.9 


151 
56.7 


161 

58.4 


170 
60.2 


23.73 


23 89 


58 
37.2 


68 
38.9 


77 
40.7 


87 
42.5 


96 
44.3 


106 
46.0 


115 

47.8 


125 
49.6 


134 
51.3 


144 
53.1 


153 
54.9 


163 
56.7 


172 
58.4 


23 89 


24.06 


59 
35.4 


69 
37.2 


78 
38.9 


88 
40.7 


97 
42.5 


107 
44.3 


116 
46.0 


126 
47.6 


135 
49.6 


145 
51.3 


154 
53.1 


164 
54.9 


173 
56.7 


24 06 


24.22 


61 
33.6 


71 
35.4 


80 
37.2 


90 
38.9 


99 
40.7 


109 
42.5 


lis 

44,3 


128 
46.0 


137 

47.8 


147 
49.6 


156 
51.3 


166 
53.1 


175 
54.9 


24 22 


24.38 


62 
31.9 


72 
33.6 


81 
35.4 


91 
37.2 


100 

38.9 


110 
40.7 


119 
42.5 


129 
44.3 


138 
46.0 


148 
47.8 


157 

49.6 


167 
51.3 


176 
53.1 


24.38 


24.54 


63 
30.1 


73 
31.9 


82 
33.6 


92 
35.4 


101 
37.2 


111 
38.9 


120 
40.7 


130 

42.5 


139 
44.3 


149 
46.0 


158 
47.8 


168 
49.6 


177 
51.3 


24.54 


24 70 


65 
28.3 


75 
30.1 


84 
31.9 


94 
33.6 


103 
35.4 


113 
37.2 


122 
38.9 


132 
40.7 


141 
42.5 


151 
44.3 


160 
46.0 


170 

47.8 


179 
49.6 


24 70 


24.86 


66 
26.6 


76 
28.8 


S5 
30.1 


95 
31.9 


104 
33.6 


114 
35.4 


123 
37.2 


133 
38.9 


142 
40.7 


152 
42.5 


161 
44.3 


171 
46.0 


180 

47.8 


24.86 


25.03 


68 
24.8 


78 
26.6 


87 
28.3 


97 
30.1 


106 
31.9 


116 
33.6 


125 
35.4 


135 
37.2 


144 
38.9 


154 
40.7 


163 
42.5 


173 
44.3 


1S2 
46.0 


25 03 


25 19 


69 
23.0 


79 
24.8 


88 
26.6 


98 
28.3 


107 
30.1 


117 
31.9 


126 
33.6 


136 
35.4 


145 
37.2 


155 

38.9 


164 
40.7 


174 
42.5 


183 
44.3 


25 19 


25.35 


70 
21.2 


80 
23.0 


89 
24.8 


99 
26.6 


108 
28.3 


118 
30.1 


127 
31.9 


137 
33.6 


146 
35.4 


156 
37.2 


165 
38.9 


175 
40.7 


184 
42.5 


25.35 


25.51 


72 
19.5 


82 
21.2 


91 
23.0 


101 

24.8 


110 
26.6 


120 

28.3 


129 
30.1 


139 
31.9 


148 
33.6 


158 
35.4 


167 
37.2 


177 
38.9 


186 
40.7 


25.51 


25.68 


73 
17.7 


83 
19.5 


92 
21.2 


102 
23.0 


111 

24.8 


121 
26.6 


130 

28.3 


140 
30.1 


149 
31.9 


159 
33.6 


168 
35.4 


178 
37.2 


187 
38.9 


25.68 


25.84 


75 
15.9 


85 
17.7 


94 
19.5 


104 
21.2 


113 
23.0 


123 

24.8 


132 
26.6 


142 
28.3 


151 
30.1 


161 
31.9 


170 
33.6 


180 
35.4 


189 
37.2 


25.84 


26 00 


76 
14.2 


86 
15.9 


95 
17.7 


105 
19.5 


114 

21.2 


124 
23 


133 

24.8 


143 
26.6 


152 

28.3 


162 
30.1 


171 
31.9 


181 
33.6 


190 

35.4 


26 00 




8.8 


8.9 


9.0 


9.1 


9.2 


9.3 


9.4 


9.5 


9.6 


9.7 


9.8 


9.9 


10.0 





378 



Ice Cream Mixes 



TABLE 68 (Continued). 



standardising 
table for ice 
cream mix. 
No. 2 testing 



r 8.007o Fat 

J l:i.r>0'/, iM. S. N. F. 

1 13.00% Sugar 

i ..'50% Gelatin 

34.00% T. S. 



-Basis 1000 pounds of 

mix. 
Top and Ijoltom lines: 

Fat tests. 
Side columns: 

S. N. F. tests. 



Tn each sfiuare: 

Top figure; Pounds butter. 

Center tlgure : Pounds water. 

Bottom figure: Poumls skim-milk 
powder. 
(Blanks indicate none of kind required. 





8 8 


8 9 


9 


9 1 


9 2 


9 3 


9 4 


9 5 


9 6 


9 7 


9.8 


9 9 


10 




26.16 


77 
12.4 


87 
14.2 


96 
15.9 


106 
17.7 


115 
19.5 


125 
21.2 


134 
23.0 


144 

24.8 


153 
26.6 


163 
28.3 


172 
30.1 


182 
31.9 


191 
33.6 


26.16 


26.32 


79 
10.6 


89 
12.4 


98 
14.2 


108 
15.9 


117 
17.7 


127 
19.5 


136 
21.2 


146 
23.0 


155 
24.8 


105 
26.6 


174 
28.3 


184 
30.1 


193 
31.9 


26.32 


26.49 


80 
8.9 


90 
10.6 


99 
12.4 


109 
14.2 


118 
15.9 


128 
17.7 


137 
19.5 


147 
21.2 


156 
23.0 


166 
24.8 


175 
26.6 


185 
28.3 


194 
30.1 


26.49 


26 66 


82 
7.1 


92 

8.9 


101 
10.6 


111 
12.4 


120 
14.2 


130 
15.9 


139 
17.7 


149 
19.5 


158 
21.2 


168 
23.0 


177 
24.8 


187 
26.6 


196 

28.3 


26.66 
26.82 


26.82 


83 
S.3 


93 

7.1 


102 

8.9 


112 
10.6 


121 
12.4 


131 
14.2 


140 
15.9 


150 
17.7 


159 
19.5 


169 
21.2 


178 
23.0 


188 
24.8 


197 
26.6 


26 98 


84 
3.5 


94 
5.3 


103 
7.1 


113 

8.9 


122 
10.6 


132 
12.4 


141 
14.2 


151 
15.9 


160 

17.7 


170 
19.5 


179 
21.2 


189 
23.0 


198 

24.8 


26.98 


27.14 


86 
1.8 


96 
3.5 


105 
5.3 


115 
7.1 


124 
8.9 


134 
10.6 


143 
12.4 


153 
14.2 


162 
15.9 


172 
17.7 


181 
19.5 


191 
21.2 


200 
23.0 


27.14 


27.30 


87 


97 
1.8 


106 
3.5 


116 
5.3 


125 
7.1 


135 

8.9 


144 
10.6 


154 
12.4 


163 
14.2 


173 
15.9 


182 
17.7 


192 
19.5 


201 
21.2 


27.30 


27.47 


1.2 

97 


98 


108 

1.8 


118 
3.5 


127 
5.3 


137 
7.1 


146 

8.9 


156 
10.6 


165 

12.4 


175 
14.2 


184 
15.9 


194 
17.7 


203 
19.5 


27.47 


27.62 


2.4 
107 


1.2 
108 


109 


119 
1.8 


128 
3.5 


138 
5.3 


147 
7.1 


157 
8.9 


166 
10.6 


176 
12.4 


185 
14.2 


195 

15.9 


204 
17.7 


27.62 


27.78 


3.7 
116 


2.4 
118 


1.2 
119 


120 


130 

1.8 


139 
3.5 


148 
5.3 


158 
7.1 


167 

8.9 


177 
10.6 


186 
12.4 


196 
14.2 


205 
15.9 


27.78 
27.94 


27 94 


4.9 

127 


3.7 
128 


2.4 
129 


1.2 
130 


131 


141 
1.8 


150 
3.5 


160 
5.3 


169 
7.1 


179 

8.9 


188 
10.6 


198 
12.4 


207 
14.2 


28.10 


6.1 
137 


4.9 
138 


3.7 
139 


2.4 
140 


1.2 
141 


142 


152 

1.8 


161 
3.5 


170 
5.3 


180 
7.1 


189 
8.9 


199 
10.6 


208 
12.4 


28.10 
28.27 


28.27 


7.3 

147 


6.1 

148 


4.9 
149 


3,7 
150 


2.4 
151 


1.2 
152 


153 


163 
1.8 


172 
3.5 


182 
5.3 


191 
7.1 


201 

8.9 


210 
10.6 


28.43 


8.5 
156 


7.3 
157 


6.1 
158 


4.9 
160 


3.7 
161 


2.4 
162 


1.2 
163 


164 


173 

1.8 


183 
3.5 


192 
5.3 


202 
7.1 


211 

8.9 


28.43 


28 60 
28.76 


9.7 
166 


8.5 
167 


7.3 
168 


6.1 
169 


4.9 
170 


3.7 
171 


2.4 
172 


1.2 
173 


174 


184 
1.8 


193 
3.5 


203 
5.3 


212 

7.1 


28.60 
28.76 


11.0 
176 


9.7 
177 


8.5 
178 


7.3 
179 


6.1 
180 


4.9 
181 


3.7 
182 


2.4 
183 


1.2 
184 


185 


195 

1.8 


205 
3.5 


214 
5.3 


28 93 

29 09 
29.25 


12.2 
184 


11.0 
186 


9.7 

188 


8.5 
189 


7.3 
190 


6.1 
191 


4.9 
192 


3.7 
193 


2.4 
194 


1.2 
195 


196 


206 

1.8 


215 
3.5 


28.93 


13.4 
195 


12.2 
196 


11.0 
197 


9.7 
198 


8.5 
200 


7.3 
201 


6.1 
202 


4.9 
203 


3.7 
204 


2.4 
20S 


1.2 
206 


207 


217 
1.8 


29 09 


14. e 

204 


13 4 

2oe 


12 1 
207 


11. C 

20>^ 


9.7 
20t 


8.f 
21C 


7.C 
211 


6.1 

21i 


4.E 
2U 


3.7 
21£ 


2.4 
21£ 


1.1 
21" 


218 


29 25 




St 


8.S 


9 C 


9 1 


9 5 


9.; 


S.< 


9.£ 


9.< 


; 9 ■ 


9 J 


9 J 


10 





Compositions of Mixes 



379 



r 9.00% Fat 
Standardizing ) 11.50%, M. S. N. F. 

table for ice 1 13.00% Sugar 
cream mix [ .50% Gelatin 

No. 4 testing: 

.•(4.00% T. S. 



TABLE 69. 

Basis 1000 pounds of 

mix. 
Top and bottom Unes: 

Pat tests. 
Side coiurans: 

S. N. F. tests. 



Ill eaoli sciuare: 
Top figure: Pounds butter. 
Center figure: Pounds water. 
Bottom figure: Pounds sl(im-nii]l< 
powder. * 

(Blanlis indicate none of l<ind required.) 





7.0 


7.1 


7.2 


7.3 


7.4 


7.5 


7.6 


7.7 


7.8 


7.9 


8.0 


8.1 


8.2 


8.3 




22.56 


31.6 
.33.6 


30.2 
33 . 4 


38. 8 
33.2 


.27.4 
33.0 


26.0 
32.8 


24.6 
32.6 


23.2 
32.4 


21.8 
32.3 


20.4 
32.1 


19.0 
31.9 


17.6 
31 .7 


16.1 
31.5 


14.7 
31.4 


13.3 
31.2 


22 56 


22.68 


31.4 
32.1 


30.0 
31 .9 


28.6 
31.7 


27.1 
31.5 


25.9 
31.3 


24.4 
30.9 


23.0 
30.8 


21.7 
30.6 


20.3 
30.4 


18.7 
30 . 2 


17.3 
30.0 


15.9 
29.9 


14.5 
29.9 


13.1 

29.7 


22.68 


22.81 


31.2 
30.6 


29.8 
30.4 


28.4 
30.2 


27.0 
30.0 


25.7 
29.8 


24.2 
29.5 


22.9 
29.4 


21.5 
29.2 


20.1 
29.0 


18.5 
28.9 


17.1 

28.7 


15.7 
28.5 


14.3 
28.3 


12.9 

28.1 


22.81 


22.93 


31.1 
30.1 


29.6 
29.0 


28.2 
28.8 


26.8 
28.6 


25.5 

28.4 


24.0 
28.2 


22.7 
28.0 


21.3 

27.8 


19.9 

27.7 


18.3 
27.5 


16.9 
27.3 


15.5 
27.1 


14.1 
27.0 


12.7 
26.8 


22 93 


23.05 


30.9 
27.6 


29.5 
27.4 


28.1 
27.2 


26.7 
27.0 


25.3 
26.9 


23.8 
26.7 


22.6 
26.5 


21.1 
26.3 


19.8 
26,2 


18.1 
26.0 


16.8 
25.8 


15.3 
25.6 


13.9 
25.4 


12.6 
25.3 


23 05 


23 17 


30.7 
26.1 


29.4 
26.0 


27.9 
25.8 


26.5 
25.6 


25.1 
25.4 


23.7 
25.2 


22.4 
25.1 


21.0 
24.9 


19.6 
24.7 


18.0 
24.5 


16.5 
24.3 


15.1 
24.1 


13.8 
23.9 


12.5 
23.8 


23. 17 


23.29 


30.6 
24.7 


29.2 
24.5 


27.7 
24.3 


26.3 
24.1 


24.9 
23.9 


23.6 
23.7 


22.2 
23.5 


20.8 
23.4 


19.4 
23.2 


17.8 
23.0 


16.3 

22.8 


14.9 
22.6 


13.6 
22.4 


12.3 
22.2 


23.29 
23.42 


23.42 


30.4 
23.2 


29.0 
23.0 


27.6 
22.8 


26.2 
22.6 


24.8 
22.4 


23.3 
22.2 


22.0 
22.1 


20.6 
21.9 


19.2 
21 .7 


17.6 
21.6 


16.1 
21.4 


14.8 
21.2 


13.5 
21.0 


12.1 
20.9 


23.54 


30.2 
21.7 


28.8 
21.5 


27.4 
21.3 


26.0 
21.1 


24.7 
20.9 


23.1 
20.8 


21.8 
20.6 


20.5 
20.4 


19.0 
20.2 


17.5 
20.0 


16.0 
19.9 


14.7 
19.7 


13.3 
19.5 


11.9 
19.3 


23.54 


23.66 


30.0 
20.2 


29.7 
20.0 


27.2 
19.8 


25.8 
19.6 


24.5 
19.4 


22.9 
19.3 


21.6 
19.1 


20.3 
18,9 


18.8 
18.8 


17.3 
18.6 


15.9 
18.4 


14.5 
18.2 


13.1 
18.0 


11.7 
17.8 


23.66 


23.78 


29.8 
18.7 


28.5 
18.5 


27.1 

18.4 


25.7 
18.3 


24.3 
18.1 


22.8 
17.9 


21.5 
17.7 


20.1 
17.5 


18.7 
17.3 


17.2 
17.1 


15.7 
16.9 


14.4 
16.7 


12.9 
16.5 


11.6 
16.3 


23.78 


23.91 


29.7 
17.3 


28.3 
17.1 


26.9 
16.9 


25.5 
16.7 


24.1 
16.5 


22.7 
16.3 


21.3 
16.1 


19.9 
16.0 


18.5 
15.8 


17.0 
15.6 


15.6 
15.4 


14.2 
15.2 


12.7 
15.0 


11.4 

14.8 


23.91 
24.03 
24 15 


24 03 


29.5 
15.8 


28.1 
15.6 


26.7 
15.4 


25.3 

15.2 


23.9 
15.0 


22.5 
14.8 


21.1 
14.6 


19.7 
14.4 


18.3 
14.3 


16.8 
14.1 


15.4 
13.9 


14.0 
13.7 


12.6 
13.5 


11.2 
13.3 


24 15 


29.3 
14.3 


28.0 
14.1 


26.5 
13.9 


25.1 
13.7 


23.7 
13.5 


22.4 
13.2 


20.9 
13.1 


19.6 
12.9 


18.2 
12.8 


16.6 
12.6 


15.2 
12.4 


13.9 
12.2 


12.5 
12.0 


11.1 
11.8 


24 27 


29.1 
12.8 


27.9 
12.6 


26.4 
12.4 


24.0 
12.2 


23.6 
12.0 


22.2 
11.8 


20.7 
11.6 


19.4 
11.4 


18.0 
11.2 


16.5 
11.1 


15.0 
10.9 


13.7 
10.7 


12.3 
10.5 


10.9 
10.3 


24 27 


24.39 


29.0 
11.3 


27.6 
11.1 


26.2 
10.9 


24.8 
10.7 


23.4 
10.5 


22.0 
10.3 


20.6 
10.2 


19.2 
10.0 


17.8 
9.8 


16.3 
9.6 


14.8 
9.4 


13.5 
9.2 


12.1 
9.0 


10.7 

8.8 


24.39 


24.52 


28.8 
9.8 


27.4 
9.6 


26.0 
9.4 


24.6 
9.2 


23.2 
9.0 


21.8 
8.8 


20.4 
8.6 


19.0 

8.4 


17.6 
8.2 


16.1 
8.0 


14.7 
7.9 


13.3 

7.7 


11.9 
7.5 


10.6 
7.3 


24.52 


24.64 


28.6 
8.3 


27.3 
8.1 


25.9 
7.9 


24.5 

7.7 


23.1 

7.5 


21.7 
7.3 


20.2 
7.1 


18.9 
6.9 


17.5 

6.8 


15.9 
6.6 


14.5 
6.4 


13.1 
6.2 


11.8 
6 


10.4 

5.8 


24 64 


24.76 


28.4 
6.8 


27.1 
6.6 


25.7 
6.4 


24.3 
6.2 


22.9 
6.0 


21.5 

5.8 


20.1 
5.6 


18.7 
5.4 


17.3 
5.3 


15.8 
5.1 


14.3 
4.9 


12.9 
4.7 


11.6 
4.5 


10.2 
4.3 


24.76 


24.88 


28.3 
5.3 


26.9 
5.1 


25.3 
4.9 


24.1 
4.7 


22.7 
4.5 


21.3 
4.3 


19.9 
4.1 


18.5 
3.9 


17.1 
3.8 


15.6 
3.6 


14.2 
3.4 


12.8 
3.2 


11.4 
3.0 


10,0 
2.8 


24.88 


25 DO 


28.1 
3.P 


26.7 
3.6 


25.3 

3.4 


23.9 
3.2 
7.3 


22.6 
3 
7.4 


21.1 
7.5 


19.7 

2 6 


18.3 

2.4 


16.9 

2? 


15.4 

2 1 


14.0 

1 .9 


12.6 
1 ,7 


11.2 
1 ." 


9.8 
1 3 


25 00 




7.0 


7.l| 7.2 


7.6 


7.7 


7.8 


7 9 


8.0 


8 1 


8.2 


8 3 





380 



Ice: Cream Mixes 



TABLE 69 (Continued). 



Stan'lardizing 
table for ice 
cream mix 
No. 4 testing : 



r 9.0091- Fat 
11.50% M. S. N. F. 
13.00% Sugar 
.50% Gelatin 



34.00% T. S. 



Basis 1000 pounds of 

mix. 
Top and bottom Unes: 

Fat tests. 
Side columns: 

S. N. F. tests. 



In eacii square: 

Top figure: Pounds butter. 

Center figure : Pounds water. 

Bottom figure: Pounds skim-milk 
powder. 
(Blanks indicate none of kind reqtiired. 





7 


7.1 


7.2 


7.3 


7.4 


7.5 


7.6 


7.7 


7.8 


7.9 


8.0 


8.1 


8.2 


8.3 




25.12 


27.9 
2.3 


26.5 
2.1 


25.1 
1.9 


23.7 
1.7 


22.3 
1.5 


20.9 
1.3 


19.5 
1.1 


18.1 
.9 


16.7 
.8 


15.2 
.6 


13.8 
.4 


12.4 
.2 


11.0 
1 


9.8 
2 


25.12 


25.24 


27.7 
.8 


26.3 
.6 


24.9 
.4 


23.5 
.2 


22.1 


20.8 
1 


19.6 
2 


18.4 
3 


17.2 
4 


15.9 
5 


14.7 
6 


13.5 

7 


12.3 

8 


11.0 
9 


25.24 


25.37 


28.2 
4 


27.0 
5 


25.8 
6 


24.5 
7 


23.3 

8 


22.1 
9 


20.8 
10 


19.6 
11 


18.4 
12 


17.2 
13 


15.9 
14 


14.7 
15 


13 5 
16 


12.3 
17 


25.37 


25.49 


29.4 
12 


28.3 
13 


27.0 
14 


25.8 
15 


24.5 
16 


23.3 
17 


22.1 
18 


20.8 
19 


19.6 
20 


18.4 
22 


17.2 
23 


15.9 
24 


14.7 
25 


13.5 
26 


25.49 


25.61 


30.7 
21 


29.4 
22 


28.2 
23 


27.0 
24 


25.8 
25 


24.5 
26 


23.3 

27 


22.1 

28 


20.8 
30 


19.6 
31 


18.4 
32 


17.2 
33 


15.9 
34 


14.7 
35 


25.61 


25.73 


31.9 
29 


30.7 
30 


29.4 
31 


28.2 
32 


27.0 
33 


25.8 
34 


24.5 
35 


23.3 
36 


22.1 
37 


20.8 
38 


19.6 
40 


18.4 
41 


17.2 
42 


15.9 
43 


25.73 


25.86 


33.1 

38 


31.9 
39 


30.7 
40 


29.4 
41 


28.2 
42 


27.0 
43 


25.8 
44 


24.5 
45 


23.3 
46 


22.1 

48 


20.8 
49 


19.6 
50 


18.4 
51 


17.2 
52 


25.86 


25.98 


34.3 
47 


33.1 

48 


31.9 
49 


30.7 
50 


29.4 
51 


28.2 
52 


27.0 
53 


25.8 
54 


24.5 
55 


23.3 
57 


22.1 

58 


20.8 
59 


19.6 
60 


18.4 
61 


25.98 


26.10 


35.5 
55 


34.3 
56 


33.1 
57 


31.9 
58 


30.7 
59 


29.4 
60 


28.2 
61 


27.0 
62 


25.8 
63 


24.5 
65 


23.3 
66 


22.1 
67 


20.8 
68 


19.6 
69 


26 10 


26 22 


36.8 
64 


35.5 
65 


34.3 
66 


33.1 

67 


31.9 

68 


30.7 
69 


29.4 
70 


28.2 
71 


27.0 
72 


25.8 
74 


24.5 
75 


23.3 

76 


22.1 
77 


20.8 

78 


26.22 


26.35 


38.0 
73 


36.8 
74 


35.5 

75 


34.3 

76 


33.1 

77 


31.9 

78 


30.7 
79 


29.4 
80 


28.2 
82 


27.0 
83 


25.8 
84 


24.5 
85 


23.3 
86 


22.1 

87 


26.35 


26.47 


39.2 
81 


38.0 

82 


36.8 
83 


35.5 

84 


34.3 

85 


33.1 

86 


31.9 

87 


30.7 

88 


29.4 
90 


28.2 
91 


27.0 
92 


25.8 
93 


24.5 
94 


23 3 
95 


26.47 


26 59 


40.5 
90 


39.2 
91 


38.0 
92 


36.8 
93 


35.5 
94 


34.3 
95 


33.1 
96 


31.9 
97 


30.7 
98 


29.4 
99 


28.2 
101 


27.0 
102 


25.8 
103 


24.5 
104 


26.59 


26.71 


41.7 
98 


40.5 
99 


39.2 
100 


38.0 
101 


36.8 
102 


35.5 
103 


34.3 
104 


33.1 
105 


31.9 
106 


30.7 
107 


29.4 
109 


28.2 
110 


27.0 
HI 


25.8 
112 


26.71 


26.84 


42.9 
107 


41.7 
108 


40.5 
109 


39.2 
110 


38.0 
111 


36.8 
112 


35.5 
113 


34.3 
114 


33.1 
115 


31.9 
116 


30.7 
118 


29.4 
119 


28.2 
120 


27.0 
121 


26.84 


26.96 


44.2 
115 


42.9 
116 


41.7 
117 


40.5 
118 


39.2 
119 


38.0 
120 


36.8 
122 


35.5 
123 


34.3 
124 


33.1 
125 


31.9 
126 


30.7 
127 


29.4 
128 


28.2 
129 


26.96 


27.08 


45.4 
124 


44.2 
125 


42.9 
126 


41.7 
127 


40.5 
128 


39.2 
129 


38.0 
130 


36.8 
131 


35.5 
132 


34.3 
133 


33.1 
134 


31.9 
135 


30.7 
136 


29.4 
137 


27.08 


27.21 


46.6 
133 


45.4 
134 


44.2 
135 


42.9 
136 


41.7 
137 


40.5 
138 


39.2 
139 


38.0 
140 


36.8 
141 


35.5 
143 


34.3 
144 


33.1 

145 


31.9 
146 


30.7 
147 


27.21 


27.32 


47.8 
141 


46.6 
142 


45.4 
143 


44.0 
144 


42.9 
145 


41.7 
146 


40.5 

148 


39.2 
149 


38.0 
150 


36.8 
151 


35.5 
152 


34.3 
153 


33.1 
154 


31.9 
155 


27.32 


27.45 


49,0 
150 


47.8 
151 


46.6 
152 


45.4 
153 


44.0 
154 


42.9 
155 


41.7 
156 


40.5 
157 


39.2 
158 


33.0 
159 


36.8 
160 


35.5 
161 


34.3 
162 


33.1 
163 


27.45 




7.0 


7.1 


7 2 


7.3 


7.4 


7.5 


7 6 


7 7 


7.8 


7.9 


8.0 


8.1 


8.2 


8.3 





Compositions of Mixes 



381 



TABLE 69 (Continued). 



standardizing 
table for ice 
cream mix 
No. 4 testing : 



9.00% Fat 
11.50% M. S. N. F. 
13.00% Sugar 
.•50% Gelatin 



34.00% T. S. 



Basis 1000 pounds of 

mix. 
Top and Ijottom lines : 

Fat tests. 
Side columns: 

S. N. F. tests. i 



In each square: 

Top figure: Pounds butter. 

Center figure: Pounds water. 

Bottom figure: Pounds skim-railk 
powder. 
(Blanks indicate none of kind required.) 





8. 


1 8. 


> 8. 


5 8. 


7 8.1 


i 8 


} 9. 


) 9. 


9. 


2 9.3 9. 


t 9. 


5 9. 


6 9.7 




22.56 


11. 
31. ( 


) 10.. 
) 30.J 


5 9. 
i 30.f 


7. 
) 30.^ 


7 6..' 
i 30.i 


J 4.< 
30. ( 


) 3.. 
) 29.' 


) 2. 
) 29.' 


.7 .4 

13 21 30 38 
r 29.5 30.5 31.8 33.1 34.4 35.8 


22.56 


22.68 


11. f 
29. f 


i 10. C 

29.4 


8.f 
29. i 


> 7.C 
29. C 


) 6.] 

28. f 


4." 

28. e 


r 3.1 

28.4 


l.E 
28.5 


28. ( 


29.1 


) 14 22 3 
30.5 31.8 33. 


39 
34.4 


22.68 


22.81 


11. e 

28. C 


10.2 

27. S 


8.- 
27. e 


7.4 
27.4 


5.C 

27.2 


4.e 

27. C 


3.1 
26. £ 


1.7 
26.7 


26.5 


27. S 


i; 
29.] 


2a 

30.5 


35 
31. f 


40 
33.1 


22.81 


22.93 


11.5 
26.6 


9.9 
26.4 


8.5 
26.2 


7.2 
26.0 


5.7 

25.8 


4.4 
25.6 


2.S 
25.4 


1.5 
25.2 


.1 

25.0 


7 
26.5 


16 

27.8 


24 
29.1 


33 
30.5 


41 
31.8 


22.93 


23 05 


11.3 
25.1 


8.7 
24.9 


8.4 
24.7 


7.0 
24.5 


5.5 
24.3 


4.2 
24.1 


2.7 
23.9 


1.3 
23.7 


23.8 


S 
25.2 


17 
26.5 


25 

27.8 


34 
29.1 


42 
30.5 


23.05 


23.17 


11.1 
23.6 


9.6 
23.4 


8.2 
23.2 


6.8 
23.0 


5.4 
22.8 


4.1 
22.6 


2.6 
22.4 


1.2 
22.2 


1 

22.5 


9 
23.8 


18 
25.2 


26 
26.5 


35 

27.8 


43 
29.1 


23 17 


23 29 


10.9 
22.0 


9.4 
21.9 


8.0 
21.7 


6.6 
21.5 


5.2 
21.3 


3.9 
21.1 


2.4 
20.9 


1.0 
20.7 


2 
21.2 


10 
22.5 


19 

23.8 


27 
25.2 


36 
26.5 


44 

27.8 


23.29 


23.42 


10.7 
20.7 


9.2 
20.5 


7.8 
20.3 


6.4 
20.1 


5.0 
19.9 


3.7 
19.7 


2.2 
19.5 


.8 
19.3 


3 
19.0 


11 

21.2 


20 
22.5 


28 
23.8 


37 
25.2 


45 
26.5 


23.42 


23.54 


10.6 
19.2 


9.1 
19.0 


7.7 
18.8 


6.2 
18.6 


4.9 
18.4 


3.5 
18.2 


2.0 
18.0 


.6 
17.8 


4 
18.5 


12 
19.9 


21 
21.2 


29 
22.5 


38 
23.8 


46 
25.2 


23.54 


23.66 


10.4 
17.7 


8.9 
17.5 


7.5 
17.3 


6.1 
17.1 


4.7 
16.9 


3.3 
16.7 


1.9 
16.5 


.5 
16.3 


5 
17.2 


13 
18.5 


22 
19.9 


30 
21.2 


39 
22.5 


47 
23.8 


23.66 


23.78 


10.2 
16.2 


8.7 
16.0 


7.3 

15.8 


6.0 
15.6 


4.5 
15.4 


3.1 
15.2 


1.7 
15.0 


.3 
14.8 


6 
15.9 


14 
17.2 


23 

18.5 


31 
19.9 


40 
21.2 


49 
22.5 


23.78 


23 91 


10.0 
14.7 


8.6 
14.5 


7.1 
14.3 


5.8 
14.1 


4.4 
13.9 


3.8 
13.7 


1.5 
13.5 


13.3 


7 
14.6 


15 
15.9 


24 
17.2 


32 

18.5 


41 

19.9 


50 
21.2 


23.91 


24 03 


9.8 
13.2 


8.4 
13.0 


7.0 
12.8 


5.8 
12.6 


4.2 
12.4 


2.8 
12.2 


1.4 
12.0 


11.8 


8 
13.3 


17 

14.6 


26 
15.9 


33 
17.2 


42 
18.5 


51 
19.9 


24 03 


24.15 


9.6 
11.7 


8.2 
11.5 


6.9 
11.3 


5.4 
11.1 


4.0 
10.9 


2.6 
10.7 


1.2 
10.5 


1 
10.6 


9 
11.8 


18 
13.3 


27 
14.6 


34 
15.9 


43 
17.2 


52 
18.5 


24.15 


24.27 


9.5 
10.2 


8.1 
10.0 


6.7 

9.8 


5.2 
9.6 


3.9 
9.4 


2.5 
9.3 


1.0 
9.0 


2 
9.3 


11 
10.6 


19 
11.8 


28 
13.3 


36 
14.6 


44 
15.9 


53 
17.2 


24.27 


24.39 


9.3 

8.7 


7.9 
8.5 


6.5 
8.3 


5.1 
8.1 


3.7 
7.9 


2.3 

7.7 


.9 
7.5 


3 
7.9 


12 
9.3 


20 
10.6 


29 
11.8 


37 
13.3 


45 
14.6 


54 
15.9 


24.39 


24.52 


9.1 
7.2 


7.8 
7.0 


6.3 
6.8 


4.9 
6.6 


3.5 
6.4 


2.1 
6.2 


.7 
6.0 


4 
6.6 


13 
7.9 


21 
9.3 


30 
10.6 


38 
U.8 


46 
13.3 


55 
14.6 


24.52 


24.64 


8.9 
5.7 


7.6 
5.5 


6.2 
5.3 


4.7 
5.1 


3.3 
4.9 


2.0 
4.7 


.5 
4.5 


5 
5.3 


14 
6.6 


22 
7.9 


31 
8.3 


40 
10.6 


47 
11.8 


56 
13.3 


24.64 


24.76 


8.8 
4.2 


7.4 
4.0 


6.0 

3.8 


4.6 
3.6 


3.2 
3.4 


1.8 
3.2 


.4 
3.0 


6 
4.0 


15 
5.3 


23 
6.6 


32 

7.9 


41 
8.3 


48 
10.6 


57 
11.8 


24.76 


24.88 


8.6 
2.7 


7.2 
2.5 


5.8 
2.3 


4.4 
2.1 


3.0 
1.9 


1.6 
1.7 


1.4 
1.5 


7 
2.7 


16 
4.0 


24 
5.3 


33 
6.6 


42 
7.9 


49 
8.3 


59 
10.6 


24.88 


25.00 


8,4 
1.2 


7.0 
1.0 


5.6 

.8 


4.2 
.6 


2.8 
.4 


1.4 
.2 




8 
1.3 


17 

2.7 


25 
4.0 


34 
5.3 


43 
6.6 


5i 
7.9 


60 

8.3 


25.00 




8.4 


8.5 


8.6 


8.7 


8.8 


8.9 


9.0 


9.1 


9.2 


9.3 


9.4 


9.5 9.6 


9.7 





382 



Ice Cream Mixes 



standardizing 
tabic for ic 
cream mix 
No. 4 testii 



TABLE 69 (Continued). 



9.009^ Fat 
11.50^ M. S. N. 
13.00% Sugar 
.50% Gelatin 



34.00?^ T. S. 



Basis 1000 pounds of 

mix. 
Top and bottom lines: 

Fat tests. 
Side columns: 

S. N. F. tests. 



In each square: 

Top figure: rounds butter. 

Center figure: Pounds water. 

Bottom figure: Pounds skim-milk 
powiler. 
(Blanks indicate none of kind required.) 





8.4 


8.5 


8.6 


8.7 


8 8 


8.9 


9 


9.1 


9.2 


9.3 


9.4 


9.5 


9.6 


9.7 




25.12 


8.6 
3 


7.4 
4 


6. 1 


4.9 
6 


3.7 

7 


2.4 

8 


1.2 
9 


10 


18 
1.3 


26 
2.7 


35 
4.0 


44 
5.3 


52 
6.6 


61 
7.9 


25.12 


25.24 


9.8 
11 


8.6 
12 


7.4 
13 


6.1 
14 


4.9 
15 


3.7 
16 


2.4 
17 


1.2 
18 


19 


27 
1.3 


36 

2.7 


45 
4.0 


53 
5.3 


62 
6.6 


25.24 


25.37 


11.0 
19 


9.8 
20 


8.6 
21 


7.4 
22 


6.1 
23 


4.9 
24 


3.7 
25 


2.4 
26 


1.2 
27 


28 


37 
1.3 


46 
2,7 


54 
4.0 


63 
5.3 


25.37 


25.49 


12.3 

28 


11.0 
29 


9.8 
30 


8.6 
31 


7.4 
32 


6.1 
33 


4.9 
34 


3.7 
35 


2.4 
36 


1.2 

37 


38 


47 
1.3 


55 
2.7 


64 
4.0 


25 49 


25.61 


13.5 
37 


12.3 
38 


11.0 
39 


9.8 
40 


8.6 
41 


7.4 
42 


6.1 
43 


4.9 

44 


3.7 
45 


2.4 
46 


1.2 
47 


48 


56 
1.3 


65 
2.7 


25.61 


25.73 


14.7 
45 


13.5 
46 


12.3 
47 


11.0 

48 


9.8 
49 


8.6 
50 


7.4 
51 


6.1 
52 


4.9 
53 


3.7 

54 


2.4 
55 


1.2 
56 


57 


66 
1.3 


25.73 


25.86 


15.9 
54 


14.7 
55 


13.5 
56 


12.3 
57 


U.O 

58 


9.8 
59 


8.6 
60 


7.4 
61 


6.1 
62 


4.9 
63 


3.7 
64 


2.4 
65 


1.2 
66 


67 


25.86 


25.98 


17.2 
62 


15.9 
63 


14.7 
64 


13.5 
65 


12.3 
66 


11.0 
67 


9.8 
68 


8.7 
69 


7.4 
70 


6.1 
71 


4.9 

72 


3.7 
73 


2.4 

74 


1.2 
75 


25.98 


26.10 


18.4 
70 


17.2 
71 


15.9 
72 


14.7 
73 


13.5 

74 


12.3 
75 


11.0 
76 


9.8 
77 


8.7 
78 


7.4 
79 


6.1 
80 


4.9 
81 


3.7 
82 


2.4 
83 


26.10 


26.22 


19.6 

79 


18.4 
80 


17.2 
81 


15.9 
82 


14.7 
83 


13.5 

84 


12.3 

85 


U.O 

86 


9.8 

87 


8.7 
88 


7.4 
89 


6.1 
90 


4.9 
91 


3.7 
92 


26.22 


26.35 


20.8 

88 


19.6 
89 


18.4 
90 


17.2 
91 


15.9 
92 


14.7 
93 


13.5 
94 


12.3 
95 


U.O 
96 


9.8 
97 


8.6 
98 


7.4 
99 


6.1 
100 


4.9 
101 


26.35 


26.47 


22.1 
96 


20.8 
97 


19.6 

98 


18.4 
99 


17.2 
100 


15.9 
101 


14.7 
102 


13.5 
103 


12.3 
104 


U.O 
105 


9.8 
106 


8.6 
107 


7.4 
108 


6.1 
109 


26 47 


26.59 


•23.3 
105 


22.1 
106 


20.8 
107 


19.6 
108 


18.4 
109 


17.2 
110 


15.9 
111 


14,7 
112 


13.5 
113 


12.3 
114 


U.O 
115 


9.8 
116 


8.6 
117 


7.4 
118 


26 59 


26.71 


24.5 
113 


23.3 
114 


22.1 
115 


20.8 
116 


19.6 
117 


18.4 
118 


17.2 
119 


15.9 
120 


14.7 
121 


13.5 
122 


12.3 
123 


U.O 
124 


9.8 
125 


8.6 
126 


26 71 


26.84 


25.8 
122 


24.5 
123 


23.3 
124 


22.1 
125 


20.8 
126 


19.6 
127 


18.4 
128 


17.2 
129 


15.9 
130 


14.7 
131 


13.5 
132 


12.3 
133 


U.O 
134 


9.8 
135 


26.84 


26.96 


27.0 
130 


25.8 
131 


24.5 
132 


23 . 3 
133 


22.1 
134 


20.8 
135 


19.6 
136 


18.4 
137 


17.2 
138 


15.9 
139 


14.7 
140 


13.5 
141 


12.3 
142 


U.O 
143 


26.96 


27.08 
27.21 


28.2 
138 


27.0 
139 


25.8 
140 


24.5 
141 


23.3 
142 


22.1 
143 


20.8 
144 


19.6 
145 


18.4 
146 


17.2 
147 


15.9 

148 


14.7 
149 


13.5 
150 


12.3 
151 


27.08 


29.4 
147 


28.2 
148 


2:?.o 

149 


25.8 
150 


24.5 
151 


23.3 
152 


22.1 
153 


20.8 
154 


19.6 
155 


18.4 
156 


17.2 
157 


15.9 
158 


14.7 
159 


13.5 
160 


27.21 


27.33 


30.7 
156 


29.4 
157 


28.2 
158 


27.0 
159 


25.8 
160 


24.5 
161 


23.3 
162 


22.1 
163 


20.8 
164 


19.6 
165 


18.4 
166 


17.2 
167 


15.9 
168 


14.7 
169 


27.33 


27.45 


31.0 
168 


30 7 

169 


29.4 
170 


28.2 
171 


27.0 
172 


25.8 
173 


24.5 

174 


23 . 3 
175 


22.1 
176 


20.8 
177 


19.6 

178 


18.4 
179 


17.2 
180 


15.9 
181 


27.45 




8.4 


8.5 


8.6 


'8.7 


8.8 


8.9 


9.0 


9.1 


9.2 


9.3 


9.4 


9.5 


9.6 


9.7 



Compositions op Mixks 



383 



TABLE 69 (Continued). 



standardizing 
table for ice 
cream mix 
No. 4 testing 



r 9.00% Pat 

J 11.50% M. S. N. F. 

I 13,00%. Sugar 

L .50% Gelatin 



a4.00% T. S. 



Basi.< 1000 iiouiids of 

mi.v. 
Top and bottom lines : 

Fat tests. 
Siile eolumns: 

S. N. F. tests. 



In each square: 

ToiJ titiure: Pounds butter. 

Center figure: Pounds water. 

Bottom figure: Pounds skim-milk 
powder. 
(Blanks indicate none of kind reguired.) 





9 8 


9 9 


10.0 


10 1 


10.2 


10.3 


10.4 


10.5 


10.6 


107. 


10.8 


10 9 


110 




22.56 


47 
37.1 


55 
38.4 


63 
39.7 


72 
41.1 


80 
42.4 


89 
43.7 


97 
45.0 


106 
46.4 


114 

47.7 


122 
49.0 


131 
50.4 


139 
51.6 


148 
52.9 


22.56 
22.68 


22.68 


48 
35.8 


56 

37.1 


64 

38.4 


72 
39.7 


81 
41.1 


90 
42.4 


98 
43.7 


107 
45.0 


115 

46.4 


123 
47.7 


132 
49.0 


140 

50.4 


149 
51.6 


22.81 


49 
3-t.4 


57 
35.8 


65 
37.1 


72 
38.4 


82 
39.7 


91 
41.1 


99 
42.4 


108 

43.7 


116 
45.0 


124 
46.4 


133 
47.7 


141 
49.0 


150 
50.4 


22.81 


22.93 


50 
33.1 


58 
34.4 


66 
35.8 


74 
37.1 


83 
38.4 


92 
39.7 


100 
41.1 


109 
42.4 


117 
43.7 


125 
45.0 


134 
46.4 


142 

47.7 


151 
49.0 


22.93 


23.05 


51 
31.8 


59 
33.1 


67 
34.4 


75 
35.8 


84 
37.1 


93 
38.4 


102 
39.7 


110 
41.1 


118 
42.4 


125 
43.7 


135 
45.0 


143 
46.4 


152 

47.7 


23.05 


23.17 


52 
30.5 


60 
31.8 


68 
33.1 


76 
34.4 


85 
35.8 


94 
37.1 


102 
38.4 


111 
39.7 


119 
41.1 


127 

42.4 


136 
43.7 


144 
45.0 


153 
46.4 


23.17 
23.29 


23.29 


53 
29.1 


61 
30.5 


69 
31.8 


78 
33.1 


86 
34.4 


95 
35.8 


103 
37.1 


112 
38.4 


120 
39.7 


128 
41.1 


137 
42.4 


145 
43.7 


154 
45.0 


23 42 


54 

27.8 


62 
29.1 


70 
30.5 


79 
31.8 


87 
33.1 


96 
34.4 


104 

35.8 


113 
37.1 


121 
38.4 


129 
39.7 


138 
41.1 


146 
42.4 


155 
43.7 


23.42 


23.54 


55 
26.5 


63 

27.8 


71 
29.1 


80 
30.5 


88 
31.8 


97 
33.1 


105 
34.4 


115 
35.8 


122 
37.1 


130 
38.4 


139 
39.7 


147 
41.1 


156 
42.4 


23.54 


23.66 


57 
25.2 


64 
26.5 


72 
27.8 


81 
29.1 


89 
30.5 


99 
31.8 


107 
33 . 1 


116 
34 . 4 


124 
35.8 


131 
37.1 


140 

38.4 


144 
39.7 


157 
41.1 


23.66 


23.78 


58 
23.8 


65 
25.2 


73 
26.5 


82 
27.8 


90 
29.1 


100 
30 . 5 


108 
31.8 


117 
33.1 


125 
34.4 


132 

35.8 


141 
37.1 


145 
38.4 


158 
39.7 


23.78 


23.91 


59 
22.5 


66 
23.8 


74 
25.2 


84 
26.5 


92 
27.8 


101 
29.1 


109 
30.5 


118 
31.8 


128 
33.1 


134 
34.4 


143 

35.8 


151 
37.1 


160 
38.4 


23.91 


24.03 


60 
21.2 


68 
22.5 


76 
23.8 


85 
25.2 


93 
26.5 


102 

27.8 


110 
29.1 


119 
30.5 


127 
31.8 


135 
33.1 


144 
34.4 


152 
35.8 


161 
37.1 


24.03 


24.15 


61 
19.9 


69 
21.2 


77 
22.5 


86 
23.8 


94 
25.2 


103 
26.5 


111 

27.8 


120 
29.1 


128 
30.5 


136 
31.8 


145 
33.1 


153 
34.4 


162 
35.8 


24.15 


24.27 


62 
18.5 


70 
19.9 


78 
21.2 


87 
22.5 


95 
23.8 


104 
25.2 


112 
26.5 


121 

27.8 


129 
29.1 


137 
30.5 


146 
31.8 


154 
33.1 


163 
34.4 


24.27 


24.39 


63 
17.2 


71 
18.5 


79 
19.9 


88 
21.2 


96 
22.5 


105 
23.8 


113 
25.2 


122 
26.5 


130 

27.8 


138 
29.1 


147 
30.5 


155 
31.8 


164 
33.1 


24.39 


24.52 


64 
15.9 


72 
17.2 


80 
18.5 


89 
19.9 


97 
21.2 


106 
22.5 


114 
23.8 


123 
25.2 


131 
26.5 


139 

27.8 


148 
29.1 


156 
30.5 


165 
31.8 


24.52 


24.64 


65 
14.6 


73 
15.9 


81 
17.2 


90 
18.5 


98 
19.9 


107 
21.2 


115 

22.5 


124 
23.8 


132 
25.2 


140 
26.5 


149 
27.8 


157 
29.1 


166 
30.5 


24.64 


24.76 


66 
13.3 


74 
14.6 


82 
15.9 


91 
17.2 


99 
18.5 


108 
19.9 


116 
21.2 


125 

22.5 


133 
23.8 


141 
25.2 


150 

26.6 


159 
27.8 


168 
29.1 


24.76 


24.88 


67 
11.9 


75 
13.3 


84 
14.6 


93 
15.9 


101 
17.2 


109 
18.5 


117 
19.9 


126 
21.2 


135 
22.5 


143 
23.8 


152 
25.2 


159 
26.5 


168 

27.8 


24.88 


25.00 


68 
10.6 


76 
11.9 


85 
13.3 


94 
14.6 


102 
15.9 


110 
17.2 


lis 

18.5 


127 
19.9 


136 
21.2 


144 
22.5 


153 
23.8 


161 
25.2 


169 
26.5 


25.00 




9.8 


9.9 


10.0 


10.1 


10.2 


10.3 


10.4 


10.5 


10.6 


10.7 


10.8 


10.9 


11.0 





384 



Ice Cream Mixes 



TABLE 69 (Continued). 



standardizing 
table for ice 
cream mix 
No. 4 testing : 



r 9.00% Pat 
■ 11.50% M. S. N. F. 
13.00% Sugar 
.50% Gelatin 



34.00% T. S. 



Dasis 1000 ijouiuis of 

mix. 
Top and bottom lines : 

Fat tests. 
Side oolurans: 

S. N. F. tL-sts. 



In each square: 

Top figure: Pounds butter. 

Center figure: Pounds water. 

Bottom figure: Pounds skim-milk 
powder. 
(Blanks Indicate none of kind reauired.) 





9 8 


9.9 


10.0 


10.1 


10 2 


10.3 


10.4 


10.5 


10.6 


10.7 


10.8 


10.9 


11.0 




25.12 


69 
9.3 


78 
10.6 


86 
11.9 


95 
13.3 


103 
14.6 


111 
15.9 


119 
17.2 


128 
18.5 


138 
19.9 


145 
21.2 


154 
22.5 


162 

23.8 


171 
25.2 


25.12 


25.24 


70 
7.9 


79 
9.3 


87 
10.6 


96 
11.9 


104 
13.3 


113 
14.6 


120 
15.9 


129 

17.2 


138 
18.5 


146 
19.9 


155 
21.2 


163 
22.5 


172 
23.8 


25.24 


25.37 


71 
6.6 


80 
7.9 


88 
9.3 


97 
10.6 


105 
11.9 


114 
13.3 


122 
14.6 


130 
15.9 


139 
17.2 


147 
18.5 


156 
19.9 


164 
21.2 


173 
22.5 


25.37 


25 49 


72 
5.3 


81 
6.6 


89 
7.9 


98 
9.3 


106 
10.6 


115 
11.9 


123 
13.3 


131 
14.6 


140 

15.9 


148 
17.2 


157 
18.5 


165 
19.9 


174 
21.2 


25.49 


25.61 


73 
4.0 


82 
5.3 


90 
6.6 


99 
7.9 


107 
9.3 


116 
10.6 


124 
11.9 


132 
13.3 


141 
14.6 


149 
15.9 


158 
17.2 


166 

18.5 


175 
19.9 


25.61 


25.73 


74 
2.7 


83 
4.0 


91 
5.3 


100 
6.6 


108 
7.9 


117 
9.3 


125 
10.6 


133 
11.9 


142 
13.3 


150 

14.6 


159 
15.9 


167 
17.2 


176 
18.5 


25.73 


25.86 


75 
1.3 


84 
2.7 


92 
4.0 


101 
5.3 


109 
6.6 


lis 

7.9 


126 
9.3 


134 
10.6 


143 
11.9 


151 
13.3 


160 
14.6 


168 
15.9 


177 
17.2 


25.86 


25 98 


76 


85 
J1.3 


93 

2.7 


102 
4.0 


110 

5.3 


119 
6.6 


127 
7.9 


135 
9.3 


144 
10.6 


152 
11.9 


161 
13.3 


169 
14.6 


179 
15.9 


25.98 


26 10 


1.2 

85 


86 


94 
1.3 


103 
2.7 


111 
4.0 


120 
5.3 


128 
6.6 


136 

7.9 


145 
9.3 


154 
10.6 


162 
11.9 


171 
13.3 


180 
14.6 


26 10 


26.22 


2.4 
93 


1.2 
94 


95 


104 
1.3 


112 
2.7 


121 
4.0 


129 
5.3 


137 
6.6 


146 
7.9 


155 
9.3 


163 
10.6 


172 
11.9 


181 
13.3 


26.22 


26.35 


3.7 
102 


2.4 
103 


1.2 
104 


105 


113 
1.3 


122 

2.7 


130 
4.0 


138 
5.3 


146 
6.6 


156 

7.9 


164 
9.3 


173 
10.6 


182 
11.9 


26.35 


26.47 


4.9 

no 


3.7 
111 


2.4 
112 


1.2 
113 


114 


123 
1.3 


131 
2.7 


140 
4.0 


149 
5.3 


157 
6.6 


166 

7.9 


174 
9.3 


183 
10.6 


26.47 


26.59 


6.1 
119 


4.9 
120 


3.7 
121 


2.4 
122 


1.2 
123 


124 


132 
1.3 


141 
2.7 


150 
4.0 


158 
5.3 


167 
6.6 


175 
7.9 


184 
9.3 


26.59 


26.71 


7.4 
127 


6.1 

128 


4.9 
129 


3.7 
130 


2.4 
131 


1.2 
132 


133 


144 
1.3 


151 
2.7 


159 
4.0 


168 
5.3 


176 
6.6 


185 
7.9 


26 71 


26.84 


8.6 
136 


7.4 
137 


6.1 
138 


4.9 
139 


3.7 
140 


2.4 
141 


1.2 
142 


143 


152 
1.3 


160 
2.7 


169 
4.0 


177 
5.3 


186 
6.6 


26.84 


26 96 


9.S 
145 


8.6 
146 


7.4 
147 


6.1 
148 


4.9 
149 


3.7 
ISO 


2.4 
151 


1.2 
152 


153 


161 
1.3 


170 
2.7 


178 
4.0 


187 
5.3 


26.96 


27.08 


11.0 
153 


9.8 
154 


8.6 
155 


7.4 
156 


6.1 
157 


4.9 
158 


3.7 
159 


2.4 
160 


1.2 
161 


162 


171 
1.3 


179 
2.7 


188 
4.0 


27.08 


27.21 


12.3 
162 


11.0 
163 


9.8 
164 


8.6 
165 


7.4 
166 


6.1 
167 


4.9 
168 


3.7 
169 


2.4 
170 


1.2 
171 


172 


180 
1.3 


189 
2.7 


27.21 


27.33 


13.5 
170 


12.3 
171 


11.0 
172 


9.8 
173 


8.6 
174 


7.4 
175 


6.1 
176 


4.9 
177 


3.7 

178 


2.4 
179 


1.2 
180 


181 


190 
1.3 


27.33 


27.45 


14.7 
179 


13.5 
180 


12.3 
181 


U .0 

182 


9.8 
183 


8.6 
184 


7.4 

185 


6.1 

186 


4.9 

187 


3.7 

188 


2.4 
189 


1.2 
190 


191 


27.45 




9 8 


9.9 


10 


10 1 


10.2 


10.3 


10 4 


10 5 


10 6 


10.7 


10.8 


10.9 


11.0 





Compositions of Mixes 



385 



standardizing 
table for ice 
cream mix 
No. 5 testing: 



10.00% Fat 
10.50% M. S. N. F. 
14.00% Sugar 
.50% Gelatin 



34.00% T. S. 



TABLE 70. 

Basis 1000 pounds of 

mix. 
Top and bottom Unes : 

Fat tests. 
Side colimins: 

S. N. F. tests. 



In each square: 

Top figure : Pounds butter. 

Center figure: Pounds water. 

Bottom figure: Pounds skim -milk 
powder. 
(Blanks indicate none of kind required.) 





8.0 


8.1 


8,2 


8.3 


8,4 


8,5 


8,6 


8,7 


8,8 


8,9 


9 


9 1 


9,2 


9,3 






22.80 


32.2 
31.1 


30. S 
30.8 


29,3 
30,7 


27.9 
30,5 


26, S 
30,3 


25,1 
30,1 


23,6 

29, S 


22.2 
29,7 


20, i 

29,6 


19,3 
29.4 


17, E 
29, i 


16,5 
29,0 


15.0 

28,8 


13,6 
28.6 


22,80 




22.91 


32.2 
29.7 


30.6 
29.5 


29,1 
29.3 


27,7 
29,1 


26,3 
28,9 


24,9 
28,7 


23,4 

28,5 


22,0 
28,3 


20,6 
28,1 


19,1 
28,0 


17.7 

27,8 


16,3 
27,6 


14,8 
27,4 


13,4 
27,2 


22.91 




23.02 


32.0 
28.4 


30.4 

28.2 


28,9 
28,0 


27,5 
27.8 


26,2 
27,6 


24,7 
27,4 


23,2 
27,2 


21,8 
27,0 


20,5 
26,8 


IS, 9 
26.6 


17,5 
26,5 


16,1 
26,3 


14.6 
26,1 


13,2 
25,9 


23,02 




23.13 


31.8 
27.0 


30.2 
26.8 


28,7 
26,6 


27.3 
26,4 


26,0 
26,2 


24,5 
26,0 


23,0 
25,8 


21,6 
25.6 


20,3 
25,4 


18,7 
25,2 


17,3 
25,1 


16,0 

24,9 


14,4 
24,7 


13,0 
24,5 


23,13 




23.24 


31.6 
25.7 


30.0 
25.5 


28,5 
25,3 


27,1 
25,1 


25,8 
24,9 


24,3 
24,7 


22,8 
24,5 


21,4 
24,3 


20,2 
24,1 


18,5 
24,0 


17,1 
23,8 


15,8 
23,6 


14,2 
23.4 


12,8 
23,2 


23,24 




23.35 


31.5 
24.3 


29.9 
24.1 


28,4 
23,9 


27,0 
23,7 


25,6 
23,5 


24,1 
23,3 


22,7 
23,1 


21,2 
22,9 


20,0 
22,7 


18,3 
22,5 


17,0 
22,4 


15.6 
22,2 


14,1 
22,0 


12,7 
21.8 


23.35 




23.46 


31.3 
22.9 


29.8 
22.7 


28,2 
22,5 


26,8 
22,3 


25,4 
22,1 


24,0 
21,9 


22,5 
21,7 


21,1 
21,5 


19,8 
21,3 


18,1 
21,1 


16,8 
20,9 


15,4 
20.8 


13,9 
20,6 


12,5 
20,4 


23 46 




23.57 


31.1 
21.6 


29.6 
21.4 


28,0 
21,2 


26.6 
21,0 


25.2 
20,8 


23,8 
20.0 


22,3 
20,4 


20,9 
20,2 


19,6 
20,0 


ISO 
19,8 


16,6 
19,6 


15,2 
19,5 


13,7 
19,3 


12.3 
19,1 


23,57 




23.68 


30.9 
20.2 


29.4 
20.0 


27,9 
19,8 


26,4 
19,6 


25.0 
19,4 


23,6 
19,2 


22,2 
19,0 


20,7 

18,8 


19,4 
18,6 


17,8 
18,4 


16,4 
18,3 


15.0 
18,1 


13,5 
17,9 


12,1 
17,7 


23 68 




23.79 


30.8 
18.9 


29.2 
18.7 


27.7 
18,5 


26,3 
18,3 


24,9 
18.1 


23,4 
17,9 


22,0 
17.7 


20,5 
17,5 


19,2 
17,3 


17,6 
17,1 


16,2 
17,0 


14,8 
16,8 


13,3 
16,6 


11.9 
16,4 


23 79 




23 90 


30.6 
17.5 


29.0 
17.3 


27,5 
17,1 


26,1 
16,9 


24,8 
16,7 


23,2 
16,5 


21.8 
16,3 


20,3 
16,1 


19,1 
16,0 


17,4 
15,8 


16,0 
15,6 


14,6 
15,4 


13,1 
15,2 


11,8 
15,0 


23,90 




24.01 


30.4 
16.1 


28.9 
15.9 


27,3 
15,7 


26,0 
15,5 


24,6 
15.3 


23,0 
15,1 


21,7 
14,9 


20,1 
14,7 


18,9 
14,5 


17,2 
14,3 


15.9 
14,2 


14,4 
14,0 


12,9 
13,8 


11,6 
13,6 


24 01 




24.12 


30.2 
14.8 


28.7 
14.6 


27.2 
14.4 


25,8 
14,2 


24,4 
14,0 


22,8 
13,8 


21,5 
13,6 


20,0 
13,4 


18,7 
13,2 


17,0 
13,0 


15,7 
12,9 


14,2 
12,7 


12,8 
12,5 


11,4 
12.3 


24,12 




24.23 


30.0 
13.4 


28.5 
13.2 


27,0 
13,0 


25,6 
12,8 


24,2 
12,6 


22,6 
12,4 


21,3 
12,2 


19,8 
12,0 


18,5 
11.8 


16,8 
11,7 


15.5 
11,5 


14,0 
11,3 


12,6 
11,1 


11,2 
10,9 


24 23 




24.34 


29,7 
12.1 


28.3 
11.9 


26,9 
11,7 


25,4 
11,5 


24,0 
11,3 


22,5 
11,1 


21,1 
10,9 


19,6 
10,7 


18,3 
10,5 


16,6 
10,4 


15,4 
10,2 


13,9 
10-0 


12.4 
9,8 


11,0 
9,6 


24,34 




24.45 


29.5 
10.7 


28.1 
10.5 


26,7 
10,3 


25,2 
10,1 


23,9 
9,9 


22,3 
9,7 


21,0 
9,5 


19,4 
9,3 


18,1 
9,2 


16,4 
9,0 


15,2 

8,8 


13,7 
8,6 


12.2 
8,4 


10,9 

8,2 


24 45 




24.56 


29.3 
9.3 


27.9 
9.1 


26.5 
8,9 


25,0 

8,7 


23,7 
8,5 


22,1 
8,3 


20,8 
8,1 


19,3 
8,0 


18,0 

7,8 


16,3 
7.6 


15,0 
7,4 


13,5 
7.2 


12,0 
7,0 


10,7 
6,8 


24 56 




24.67 


29.1 
8.0 


27.8 
7.8 


26,3 
7,6 


24,8 
7,4 


23.5 
7.2 


21,9 
7,0 


20,6 
6,8 


19,1 
6,6 


17,8 
6,4 


16,1 
6.2 


14,9 
6.1 


13,3 
5,9 


11,9 
5,7 


10,5 
5,5 


24,67 




24.78 


28.9 
6.6 


27,6 
6,4 


26.1 
6,2 


24,6 
6,0 


23.3 

5.8 


21,7 
5,6 


20.4 
5,4 


19,0 
5,2 


17,6 
5,0 


15,9 
4,9 


14.7 
4,7 


13,1 
4,5 


11,8 
4,3 


10,4 
4.1 


24.78 




24.89 


28.8 
5.3 


27,4 
5,1 


25.9 
4,9 


24,5 

4,7 


23,1 
4,5 


21,5 
4,3 


20,2 
4,1 


18,8 
3.9 


17,4 
3,7 


15,7 
3,6 


14,5 
3,4 


13,0 
3,2 


11,6 
3,0 


10,2 

2,8 


24 89 




25.00 


28.6 
3.9 


27,2 
3,7 


25,7 
3,5 


24,3 
3,3 


22,9 
3,1 


21,5 

2.9 


20,0 

2,7 


18.6 
2.5 


17,2 

2,3 


15,7 
2,1 


14,3 
2,0 


12,9 
1.8 


11,4 
1.6 


10,0 

1,4 


25.00 






8.0 


8,1 


8,2 


8,3 


8,4 


8 5 


8,6 


8,7 


8 8 


8,9 


9 


9,1 


9.2 


9,3 







386 



Ice Cream Mixes 



TABLE 70 (Continued). 



standardizing 
table for ice 
cream mix 
No. 5 testing: 



10.00% Fat 
10.50% M. S. N. 
14.007o Sugar 
.50% Gelatin 



34.00% T. S. 



Basis 1000 pounds of 

mix. 
Top and bottom lines : 

Fat tests. 
Side columns : 

S. N. F. tests. 



In each sauare: 

Top figure: Pounds butter. 

Center figure: Pounds water. 

Bottom figure: Pounds sliim-mllk 
powder. 
(Blanlis indicate none of kind reauired.) 





8.0 


8.1 


8.2 


8.3 


8.4 


8.5 


8.6 


8.7 


8.8 


8.9 


9.0 


9.1 


9.2 


9.3 




25.11 


28.4 
2.5 


27.0 
2.3 


25.5 
2.1 


24.1 
1.9 


22.7 
1.7 


21.3 
1.5 


19.8 
1.3 


18.4 
1.1 


17.0 
.9 


15.5 

.7 


14.1 
.6 


12.7 

.4 


11.2 
.2 


9.8 
.0 


25.11 


25.22 


28.2 
1.2 


26.8 
1.0 


25.3 

.8 


23.9 

.7 


22.5 
.5 


21.1 
.3 


19.6 
.1 


18.4 
1 


17.2 
2 


15.9 
3 


14.7 
4 


13.5 
6 


12.3 

7 


11.0 

8 


25.22 


25.33 


28.2 
1 


27.0 
2 


25.7 
3 


24.5 
4 


23.3 
5 


22.1 
6 


20.8 

7 


19.6 

8 


18.4 
10 


17.2 
11 


15.9 
12 


14.7 
13 


13.5 

14 


12.3 
16 


25.33 


25.44 


29.4 
9 


28.2 
10 


27.0 
11 


25.7 
12 


24.5 
13 


23.3 
14 


22.1 
15 


20.8 
16 


19.6 
17 


18.4 
19 


17.. 2 
20 


15.9 
21 


14.7 
22 


13.5 
23 


25.44 


25.55 


30.6 
16 


29.4 
17 


28.2 
18 


27.0 
19 


25.7 
20 


24.5 
21 


23.3 
22 


22.1 
23 


20.8 
24 


19.6 
25 


18.4 
26 


17.2 

27 


15.9 

28 


14.7 
30 


25.55 


25. 6G 


31.9 
24 


30.6 
25 


29.4 
26 


28.2 
27 


27.0 

28 


25.7 
29 


24.5 
31 


23.3 
32 


22.1 
33 


20.8 
34 


19.6 
35 


18.4 
36 


17.2 
37 


15.9 
38 


25.66 


25.77 


33.1 
31 


31.9 
32 


30.6 
33 


29.4 
34 


28.2 
35 


27.0 
36 


25.7 
37 


24.5 
39 


23.3 
40 


22.1 
41 


20.8 
42 


19.6 
43 


18.4 
44 


17.2 
45 


25.77 


25.88 


34.3 
39 


33.1 
40 


31.9 
41 


30.6 
42 


29.4 
43 


28.2 
44 


27.0 
45 


25.7 
46 


24.5 
47 


23.3 

48 


22.1 
49 


20.8 
51 


19.6 
52 


18.4 
53 


25.88 


25.99 


35.5 
46 


34.3 
47 


33.1 

48 


31.9 
49 


30.6 
50 


29.4 
52 


28.2 
53 


27.0 
54 


25.7 
55 


24.5 
56 


23.3 
57 


22.1 

58 


20.8 
59 


19.6 
60 


25.99 


26.10 


36.8 
54 


35.5 
55 


34.3 
56 


33.1 
57 


31.9 

58 


30.6 
59 


29.4 
60 


28.2 
62 


27.0 
63 


25.7 
64 


24.5 
65 


23.3 
66 


22.1 
67 


20.8 
68 


26.10 


26 21 


38.0 
61 


36.8 
62 


35.5 
63 


34.3 
65 


33.1 
66 


31.9 
67 


30.6 

68 


29.4 
69 


28.2 
71 


27. 
72 


25.7 
73 


24.5 

74 


23.3 
75 


22.1 
76 


26 21 


26 32 


39.2 
69 


38.0 
70 


36.8 
71 


35.5 

72 


34.3 
73 


33.1 

74 


31.9 
75 


30.6 

76 


29.4 

77 


28.2 
78 


27.0 
80 


25.7 
81 


24.5 
82 


23.3 

83 


26.32 


26 43 


40.4 
76 


39.2 

77 


38.0 

78 


36.8 
79 


35.5 
80 


34.3 
81 


33.1 

82 


31.9 
83 


30.6 

84 


29.4 
85 


28.2 
86 


27.0 

88 


25.7 
89 


24.5 
91 


26.43 


26.54 


41.7 
84 


40.4 
85 


39.2 
86 


38.0 

87 


36.8 
88 


35.5 
89 


34.3 
90 


33.1 
91 


31.9 
92 


30.6 
93 


29.4 
94 


28.2 
95 


27.0 
97 


25.7 
98 


26.54 


26.65 


42.9 
91 


41.7 
92 


40.4 
93 


39.2 
94 


38.0 
95 


36.8 
96 


35.5 
97 


34.3 
98 


33.1 
99 


31.9 
100 


30.6 
101 


29.4 
102 


28.2 
103 


27.0 
104 


26 65 


26.76 


44.1 
99 


42.9 
100 


41.7 
101 


40.4 
102 


39.2 
103 


38.0 
104 


36.8 
105 


35.5 
106 


34.3 
107 


33.1 
108 


31.9 
109 


30.6 
110 


29.4 
112 


28.2 
113 


26 76 


26.87 


45.3 
106 


44 1 
107 


42.9 
108 


41.7 
109 


40.4 
110 


39.2 
111 


38.0 
113 


36.8 
114 


35.5 
115 


34.3 
116 


33.1 
117 


31.9 

lis 


30.6 
119 


29.4 
120 


26.87 


26.98 


46.6 
114 


45.3 
115 


44.1 
116 


42.9 
117 


41.7 
118 


40.4 
119 


39.2 
120 


38.0 
122 


36.8 
124 


35.5 
125 


34.3 
126 


33.1 
127 


31.9 
128 


30.6 
129 


26.98 


27.09 


47.8 
121 


46.6 
122 


45.3 
123 


44.1 
124 


42.9 
125 


41.7 
126 


40.4 
127 


39.2 

128 


38.0 
129 


36. S 
130 


35.5 
131 


34.3 
132 


33.1 
134 


31.9 
135 


27 09 


27.20 


49. 
129 


47.8 
130 


46.6 
131 


45.3 
132 


44.1 
133 


42.9 
134 


41.7 
135 


40.4 
136 


39.2 
138 


38.0 
139 


36. S 
140 


35.5 
141 


34.3 
142 


33.1 
143 


27.20 




8 


8 1 


8.2 


8.3 


8.4 


8.5 


8.6 


8.7 


8.8 


8.9 


9.0 


9 1 


9 2 


9.3 





Compositions of Mixes 



38; 



TABLE 70 (Continued). 



standardizing 
table for ice 
cream mix 
No. 5 testing: 



Fat 



icoc; 

10.507o M. S. N. 
14.00% Sugar 
L .50% Gelatin 



34.00% T. S. 



Basis 1000 pounds of 

mix. 
Top and bottom Unes: 

Fat tests. 
Side columns: 

S. N. F. tests. 



In each square: 

Top tigure: Pounds butter. 

Center figure : Pounds water. 

Bottom figure: Pounds sklm-mllk 
powder. 
(Blanks indicate none of kind reaulred. ) 





9 4 


9.5 


9.6 


9 7 


9.8 


9 9 


10.0 


10 1 


10.2 


10.3 


10.4 


10.5 


10.6 


10.7 




22.80 


12.2 
28.4 


10.7 

28.2 


9.3 
28.0 


7.9 
27.8 


6.5 
27.6 


5.0 
27.4 


3.6 
27.2 


2.2 
27.0 


.7 
26.8 


3 

27.2 


11 

28.4 


18 
29.6 


26 
30.7 


34 
31.9 


22.80 


22.91 


12.0 
27.0 


10.6 
26.8 


9.1 
26.6 


7.7 
26.4 


6.3 
26.2 


4.8 
26.0 


3.4 

25.8 


2.0 
25.6 


.5 
25.4 


4 
26.0 


12 
27.2 


19 

28.4 


27 
29.6 


35 
30.7 


22.91 


23.02 


11.8 
25.7 


10.4 
25.5 


8.9 
25.3 


7.S 
25.1 


6.1 
24.9 


4.6 
24.7 


3.2 
24.5 


1.8 
24.3 


.3 
24.1 


5 

24.8 


13 
26.0 


20 
27.2 


28 
28.4 


36 
29.6 


23.02 


23.13 


11.7 
24.3 


10.3 
24.1 


8.8 
23.9 


7.3 
23.7 


5.9 
23.5 


4.5 
23.3 


3.1 
23.1 


1.7 
22.9 


.2 
22.7 


6 
23.7 


14 

24.8 


21 
26.0 


29 
27.2 


37 

28.4 


23 13 


23.24 


11.5 
23.0 


10.1 

22.8 


8.6 
22.6 


7.2 
22.4 


5.7 
22.2 


4.3 
22.0 


2.9 
21.8 


1.5 
21.6 


.0 
21.3 


22.5 


15 
23.7 


22 

24.8 


30 
26.0 


38 
27.2 


23.24 


23.35 


11.4 
21.6 


10.0 
21.4 


8.5 
21.2 


7.0 
21.0 


5.5 
20.8 


4.1 
20.6 


2.7 
20.4 


1.3 
20.2 


1 
20.1 


8 
21.3 


15 
22 . 5 


23 
23.7 


31 

24.8 


39 
26.0 


23.35 


23 46 


11.2 
20.2 


9.8 
20.0 


8.3 
19.8 


6.8 
19.6 


5.3 
19.4 


3.9 
19.2 


2.5 
19.0 


1.1 

18.8 


2 

18.9 


9 
20.1 


16 
21.3 


24 
22.5 


32 
23.7 


40 

24.8 


23.46 


23.57 


11.0 
18.9 


9.6 
18.7 


8.1 
18.5 


6.6 
18.3 


5.1 
18.1 


3.7 
17.9 


2.3 
17.7 


.9 
17.5 


3 
17.7 


10 

18.9 


17 
20.1 


25 
21.3 


33 
22.5 


41 
23.7 


23.57 


23.68 


10.9 
17.5 


9.4 
17.3 


7.9 
17.1 


6.4 
16.9 


5.0 
16.7 


3.6 
16.5 


2.2 
16.3 


.8 
16.1 


4 
16.6 


11 
17.7 


18 
18.9 


26 
20.1 


34 
21.3 


42 
22.5 


23.68 


23.79 


10.7 
16.2 


9.2 
16.0 


7.7 
15.8 


6.2 
15.6 


4.8 
15.4 


3.4 
15.2 


2.0 
15.0 


.6 
14.8 


5 
15.4 


12 
16.6 


19 
17.7 


27 
18.9 


35 
20.1 


43 
21.3 


23.79 


23 90 


10.5 
14.8 


9.0 
14.6 


7.5 
14.4 


6.1 
14.2 


4.6 
14.0 


3.2 
13.8 


1.8 
13.6 


.4 
13.4 


6 
14.2 


13 
15.4 


20 
16.6 


28 
17.7 


36 
18.9 


44 
20.1 


23 90 


24 01 


10.4 
13.4 


8.9 
13.2 


7.3 
13.0 


5.9 
12.8 


4.4 
12.6 


3.0 
12.4 


1.6 
12.2 


.2 
12.0 


7 
13.0 


14 
14.2 


21 
15.4 


29 
16.6 


37 
17.7 


45 
18.9 


24 01 


24 12 


10.2 
12.1 


8.7 
11.9 


7.1 
11.7 


5.7 
11.5 


4.2 
11.3 


2.8 
11.1 


1.4 
10.9 


.0 
10.7 


8 
11.8 


15 
13.0 


22 
14.2 


30 
15.4 


38 
16.6 


46 

17.7 


24.12 


24.23 


10.0 
10.7 


8.5 
10.5 


6.9 
10.3 


5.5 
10.1 


4.1 
9.9 


2.7 
9.7 


1.3 
9.5 


1 
9.5 


9 
10.6 


16 
11.8 


23 
13.0 


31 
14.2 


39 

15.4 


47 
16.6 


24.23 


24.34 


9.8 
9.4 


8.3 
9.2 


6.7 
9.0 


5.3 

8.8 


3.9 
8.6 


2.5 
8.4 


1.1 

8.2 


2 
8.3 


10 
9.5 


17 
10.6 


24 
11.8 


32 
13.0 


40 
14.2 


48 
15.4 


24.34 


24.45 


9.6 
8.0 


8.1 

7.8 


6.6 
7.6 


5.2 
7.4 


3.7 
7.2 


2.3 
7.0 


.9 
6.8 


3 

7.1 


11 

8.3 


18 
9.5 


25 
10.6 


33 
11.8 


41 
13.0 


49 
14.2 


24.45 


24.56 


9.4 
6.6 


8.0 
6.4 


6.4 
6.2 


5.0 
6.0 


3.6 

5.8 


2.1 
5.6 


.7 
5.4 


4 
5.9 


12 
7.1 


19 
8.3 


26 
9.5 


34 
10.6 


42 
11.8 


50 
13.0 


24.56 


24.67 


9.2 
5.3 


7.8 
5.1 


6.2 
4.9 


4.9 
4.7 


3.4 

4.5 


1.9 
4.3 


.5 
4.1 


5 
4.7 


12 
5.9 


20 

7.1 


27 
8.3 


35 
9.5 


43 
10.6 


50 
11.8 


24.67 


24.78 


9.0 
3.9 


7.6 
3.7 


6.1 
3.5 


4.7 
3.3 


3.3 
3.1 


1.8 
2.9 


.4 
2.7 


6 
3.5 


13 
4.7 


21 

5.9 


28 
7.1 


36 

8.3 


44 
9.5 


51 
10.6 


24.78 


24.89 


8.8 
2.6 


7.4 
2.4 


5.9 
2.2 


4.5 
2.0 


3.1 

1.8 


1.6 
1.6 


.2 
1.4 


7 
2.4 


14 
3.5 


22 

4.7 


29 
5.9 


37 

7.1 


45 
8.3 


52 
9.5 


24.89 


25.00 


8.6 
1.2 


7.2 
1.0 


5.7 

.8 


4.3 

.6 


2.9 

.4 


1.4 

.2 




8 
1.2 


15 

2.4 


23 
3 5 


30 

4.7 


38 
5.9 


46 
7.1 


53 

8.3 


25 00 




9 4 


9.5 


9.6 


9 7 


9.8 


9 9 


10 


10.1 


10.2 


10 3 


10 4 


10.5 


10 6 


10 7 





388 



Ice Cream Mixes 



TABLE 70 (Continued). 



standardizing 
table for ice 
cream mix 
No. 5 testing: 



in.00'7^ Fat 

10.50% M. S. N. F. 

14.00% Sugar 

1 .50% Gelatin , 



34.00% T. S. 



Basis 1000 pounds of 

mix. 
Top and bottom lines: 

Fat tests. 
Side columns: 

S. N. F. tests. 



In each square: 

Top figure: Pounds butter. 

Center figure: Pounds water. 

Bottom figure: Pounds skim-mllk 
powder. 
(Blanks indicate none of kind required.) 





9 4 


9.5 


9.6 


9.7 


9.8 


9.9 


10.0 


10.1 


10.2 


10.3 


10.4 


10.5 


10.6 


10.7 




25.11 


8.6 

1 


7.4 
2 


6.1 
3 


4.9 
5 


3.7 
6 


2.4 

7 


1.2 

8 


9 


16 
1.2 


24 
2.4 


31 
3.5 


39 
4.7 


47 
5.9 


54 
7.1 


25.11 


25.22 


9.8 
9 


8.6 
10 


7.4 
11 


6.1 
12 


4.9 
13 


3.7 
14 


2.4 
15 


1.2 
16 


17 


25 
1.2 


32 
2.4 


40 
3.5 


48 
4.7 


55 
5.9 


25.22 


25.33 


11.0 

17 


9.8 
18 


8.6 
19 


7.4 
20 


6.1 
21 


4.9 
22 


3.7 
23 


2.4 
24 


1.2 
25 


26 


33 
1.2 


41 
2.4 


49 
3.5 


56 
4.7 


25.33 


25.44 


12.3 
24 


10.0 
25 


9.8 
26 


8.6 
27 


7.4 

28 


6.1 
29 


4.9 
30 


3.7 
31 


2.4 
32 


1.2 
33 


34 


42 
1.2 


50 
2.4 


57 
3.5 


25.44 


25.55 


13.5 
31 


12.3 
32 


11.0 
33 


9.8 
34 


8.6 
35 


7.4 
37 


6.1 

38 


4.9 
39 


3.7 
40 


2.4 
41 


1.2 
42 


43 


51 
1.2 


58 
2.4 


25.55 


25 66 


14.7 
39 


13.6 
40 


12.3 
41 


11.0 
42 


9.8 

44 


8.6 
45 


7.4 
46 


6.1 
47 


4.9 

48 


3.7 
49 


3.4 
50 


1.2 
51 


52 


59 
1.2 


25.66 


25.77 


15.9 
46 


14.7 

47 


13.5 
49 


12.3 
50 


11.0 
51 


9.8 
52 


8.6 
53 


7.4 
54 


6.1 

55 


4.9 
56 


3.7 
57 


3.4 

58 


1.2 
59 


60 


25.77 


25.88 


17.2 
54 


15.9 
55 


14.7 
56 


13.5 
57 


12.3 

58 


11.0 
60 


9.8 
61 


8.6 
62 


7.4 
63 


6.1 
64 


4.9 
65 


3.7 
66 


3.4 
67 


1.2 
68 


25.88 


25.99 


18.4 
61 


17.2 
62 


15.9 
63 


14.7 
64 


13.5 
65 


12.3 
66 


11.0 
67 


9.8 
68 


8.6 
70 


7.4 
71 


6.1 
72 


4.9 
73 


3.7 

74 


3.4 
75 


25.99 


26 10 


19.6 
69 


18.4 
70 


17.2 
71 


15.9 
72 


14.7 
73 


13.5 
74 


12.3 
75 


11 

76 


9.8 
78 


8.6 
79 


7.4 
80 


6.1 

81 


4.9 
82 


3.7 
83 


26.10 


26.21 


20.8 

77 


19.6 

78 


18.4 
80 


17.2 
81 


15.9 

82 


14.7 
83 


13.5 

84 


12.3 

85 


11.0 

86 


9.8 

87 


8.6 

88 


7.4 
89 


6.1 
90 


4.9 
91 


26.21 


26.32 


22.1 
84 


20.8 
85 


19.6 
86 


18.4 
87 


17.2 

88 


15.9 
89 


14.7 
90 


13.5 
91 


12.3 
93 


11.0 
94 


9.8 
95 


8.6 
96 


7.4 
97 


6.1 
98 


26.32 


26.43 


23.3 
92 


22.1 
93 


20.8 
94 


19.6 
95 


18.4 
96 


17.2 
97 


15.9 
98 


14.7 
100 


13.5 
101 


12.3 
102 


11.0 
103 


9.8 
104 


8.6 
105 


7.4 
106 


26.43 


26.54 


24.5 
99 


23.3 
100 


22.1 
101 


20.8 
102 


19.6 
103 


18.4 
104 


17.2 
106 


15.9 
107 


14.7 
108 


13.5 
109 


12.3 
110 


11.0 
111 


9.8 
112 


8.6 
113 


26.54 


26 65 


25.7 
106 


24.5 
107 


23.3 
108 


22.1 
109 


20.8 
110 


19.6 
112 


18.4 
113 


17.2 
114 


15.9 
116 


14.7 
117 


13.5 
118 


12.3 
119 


11.0 
120 


9.8 
121 


26.65 


26.76 


27.0 
114 


25.7 
115 


24.5 
116 


23.3 
117 


22.1 
118 


20.8 
119 


19.6 
120 


18.4 
121 


17.2 
122 


15.9 
123 


14.7 
124 


13.5 
126 


12.3 
127 


11.0 

128 


26.76 


26 87 


28.2 
121 


27.0 
122 


25.7 
123 


24.5 
125 


23.3 
126 


22.1 
127 


20,8 
128 


19.6 
129 


18.4 
130 


17.2 
131 


15.9 
132 


14.7 
133 


13.5 
134 


12.3 
135 


26 87 


26 98 


29.4 
130 


28.2 
131 


27.0 
132 


25.7 
133 


24.5 
134 


23.3 
136 


22.1 
137 


20.8 
138 


19.6 
139 


18.4 
140 


17.2 
141 


15.9 
142 


14.7 
143 


13.5 
144 


26.98 


27.09 


30.6 
136 


29.4 
137 


28.2 
138 


27.0 
140 


25.7 
141 


24.6 
142 


23.3 
143 


22.1 
145 


20.8 
146 


19.6 
147 


18.4 
148 


17.2 
149 


15.9 
150 


14.7 
151 


27 09 


27.20 


31.9 
144 


30.6 
145 


29.4 
146 


28.2 
147 


27.0 
148 


25.7 
150 


24 . 5 
151 


23.3 

152 


22.1 
153 


20.8 
154 


19.6 
155 


18.4 
156 


17.2 
157 


15.9 

158 


27 20 




9.4 


9.5 


9 6 


9.7 


9.8 


9 9 


10 


10 I 


10.2 


10 3 


10 4 


10.5 


10.6 


10.7 





Compositions of Mixes 



389 



TABLE 70 (Continued). 





1 10.009-« Fat 


Basis 1000 pounds of 


Stanaarai2ing 


j 10.50% M. S. N. F. 


mix. 


table for ice 


1 14.00% Sugar 


Top and bottom lines ; 


cream mix 


I .50% Gelatin 


Fat tests. 


No. 5 testing : 




Side oolumns: 






34.00% T. S. 


S. N. F. tests. 



In each square: 

Top figure: Pounds butter. 

Center figure: Pounds water. 

Bottom figure: Pounds skim-nnlk 
powder. 
(Blanks indicate none of kind required.) 





10.8 


10.9 


11 .0 


11.1 


11.2 


11.3 


U.4 


11.5 


11.6 


U.7 


11.8 


11 .9 


12.0 






22.80 


41 
33.1 


49 
34.3 


57 
35.5 


64 
36.7 


72 
37.8 


79 
39.0 


87 
40.2 


95 
41.4 


102 
42.6 


110 
43.8 


118 
44.9 


125 
46. 1 


133 
47.3 


22 80 




22 91 


42 
31.9 


50 
33.1 


58 
34.3 


65 
35.5 


73 
36.7 


80 

37.8 


88 
39.0 


96 
40.2 


103 
41.4 


111 
42.6 


119 
43.8 


126 
44.9 


134 
46.1 


22.91 




23 02 


43 
30.7 


51 
31.9 


59 
33.1 


66 
34.3 


74 
35.5 


81 
36.7 


89 
37.8 


97 
39.0 


104 
40.2 


112 
41.4 


120 
42.6 


127 

43.8 


135 
44.9 


23.02 




23 13 


44 
29.6 


52 
30.7 


60 
31.9 


67 
33.1 


75 
34.3 


82 
35.5 


90 
36.7 


98 
37.8 


105 
39.0 


113 
40.2 


121 
41.4 


128 
42.6 


136 

43.8 


23.13 




23.24 


45 

28.4 


53 
29.6 


61 
30.7 


68 
31.9 


76 
33.1 


83 
34.3 


91 
35.5 


99 
36.7 


106 

37.8 


114 
39.0 


122 
40.2 


129 
41.4 


137 
42.6 


23.24 




23.35 


46 
27.2 


54 

28.4 


62 
29.6 


69 
30.7 


77 
31.9 


84 
33.1 


92 
34.3 


100 
35.5 


107 
36.7 


115 

37.8 


123 
39.0 


130 
40.2 


138 
41.4 


23.35 




23.46 


47 
26.0 


55 
27.2 


63 

28.4 


70 

29.6 


78 
30.7 


85 
31.9 


93 
33.1 


101 
34.3 


108 
35.5 


116 
36.7 


124 

37.8 


131 
39.0 


139 
40.2 


23.46 




23.57 


48 
24.8 


56 
26.0 


64 
27.2 


71 
28.4 


79 
29.6 


86 
30.7 


94 
31.9 


102 
33.1 


109 
34.3 


117 
35.5 


125 
36.7 


132 

37.8 


140 
39.0 


23.57 




23.68 


49 
23.7 


57 
24.8 


65 
26.0 


72 
27.2 


80 

28.4 


87 
29.6 


95 
30.7 


103 
31.9 


110 
33.1 


118 
34.3 


126 
35 . 5 


133 
36.7 


141 

37.8 


23.68 




23.79 


50 
22.5 


58 
23.7 


66 

24.8 


73 
26.0 


81 
27.2 


88 
28.4 


96 
29.6 


104 
30.7 


111 
31.9 


119 
33.1 


127 
34.3 


134 
35.5 


142 
36.7 


23.79 




23 90 


51 
21.3 


59 
22.5 


67 
23.7 


74 
24.8 


82 
26.0 


89 
27.2 


97 

28.4 


105 
29.6 


112 
30.7 


120 
31.9 


128 
33.1 


135 
34.3 


143 
35.5 


23.90 




24 01 


52 
20.1 


60 
21.3 


68 
22.5 


75 
23.7 


83 

24.8 


90 
26.0 


98 
27.2 


106 

28.4 


113 
29.6 


121 
30.7 


129 
31.9 


136 
33.1 


144 
34.3 


24.01 




24.12 


53 
18.9 


61 
20.1 


69 
21.3 


76 
22.5 


84 
23.7 


91 

24.8 


99 
26.0 


107 
27.2 


114 

28.4 


122 
29.6 


130 
30.7 


137 
31.9 


145 
33,1 


24.12 




24.23 


54 
17.7 


62 
18.9 


70 
20.1 


77 
21.3 


85 
22.5 


92 
23.7 


100 

24.8 


108 
26.0 


115 
27.2 


123 

28.4 


131 
29.6 


138 
30.7 


146 
31.9 


24.23 




24.34 


55 
16.6 


63 
17.7 


71 
18.9 


78 
20.1 


86 
21.3 


93 
22.5 


100 
23.7 


109 

24.8 


116 
26.0 


124 

27.2 


132 

28.4 


139 
29.6 


147 
30.7 


24.34 




24.45 


56 
15.4 


64 
16.6 


72 
17.7 


79 
18.9 


86 
20.1 


94 
21.3 


101 
22.5 


110 
23.7 


117 

24.8 


125 
26.0 


133 

27.2 


140 

28.4 


148 
29.6 


24.45 




24 56 


57 
14.2 


65 
15.4 


72 
16.6 


80 
17.7 


87 
18.9 


95 
20.1 


102 
21.3 


111 

22.5 


118 
23.7 


126 

24.8 


134 
26.0 


141 
27.2 


149 

28.4 


24.56 




24 67 


58 
13.0 


65 
14.2 


73 
15.4 


81 
16.6 


88 
17.7 


96 
18.9 


103 
20.1 


111 
21.3 


119 
22.5 


127 
23.7 


135 

24.8 


142 
26.0 


150 
27.2 


24.67 




24.78 


59 
11.8 


66 
13.0 


74 
14.2 


82 
15.4 


89 
16.6 


97 
17.7 


104 
18.9 


112 
20.1 


120 
21.3 


128 
22.5 


136 
23.7 


143 

24.8 


151 
26.0 


24.78 




24.89 


60 
10.6 


67 
11.8 


75 
13.0 


83 
14.2 


90 
15.4 


98 
16.6 


105 
17.7 


113 
18.9 


121 
20.1 


129 
21.3 


137 
22.5 


144 
23.7 


152 

24.8 


24.89 




25.00 


61 

9.5 


68 
10.6 


76 
11.8 


84 
13.0 


91 

14.2 


99 
15.4 


106 
16.6 


114 
17.7 


122 
18.9 


130 
20.1 


137 

21.3 


145 
22.5 


153 
23.7 


25.00 






10.8 


10.9 


11.0 


11.1 


11.2 


11.3 


11.4 


11.5 


11.6 


11.7 


11.8 


11.9 12.0 







390 



Ice Cream Mixes 



TABLE 70 (Continued). 



standardizing 
table for ice 
cream mix 
No. 5 testing 



r 10.00% Fat 

J 10.50% M. S. N. F. 

1 14.00% Sugar 

L .50% Gelatin 



34.00% T. S. 



Basis 1000 pounds of 

mix. 
Top and bottom lines: 

Fat tests. 
Side columns: 

S. N. F. tests. 



In each square: 

Top figure : Pounds butter. 

Center figure: Pounds water. 

Bottom figure: Pounds sklra -mi 11; 
powder. 
(Blanks inilicate none of kind required.) 







10.8 


10 9 


11 .0 


111 


11 2 


11.3 


11 .4 


11 .5 


11.6 


11.7 


11.8 


11 .9 


12.00 






25.11 


62 
8.3 


69 
9.5 


77 
10. 6 


85 
11.8 


92 
13.0 


100 
14.2 


107 
15.4 


115 
16.6 


123 
17.7 


131 

18.9 


138 
20.1 


146 
21.3 


154 
22.5 


25.11 




25.22 


63 
7.1 


70 

8.3 


78 
9.5 


86 
10.6 


93 
11.8 


101 
13.0 


108 
14.2 


116 
15.4 


124 
16.6 


132 
17.7 


139 
18.9 


147 
20.1 


155 
21.3 


25.22 




25.33 


64 
5.9 


71 
7.1 


79 
8.3 


87 
9.5 


94 
10.6 


102 
11.8 


109 
13.0 


117 
14.2 


125 
15.4 


133 
16.6 


140 
17.7 


148 
18.9 


156 
20.1 


25.33 




25.44 


65 
4.7 


72 
5.9 


80 
7.1 


88 
8.3 


95 
9.5 


103 
10.6 


110 

U.8 


118 
13.0 


126 
14.2 


133 

15.4 


141 
16.6 


148 
17.7 


157 
18.9 


25.44 




25.55 


66 
3.5 


73 
4.7 


81 
5.9 


89 
7.1 


96 
8.3 


104 
9.5 


111 
10.6 


119 
11.8 


127 
13.0 


134 
14.2 


142 
15.4 


149 
16.6 


158 
17.7 


25.55 




25 66 


67 
2.4 


74 
3.5 


82 
4.7 


90 
5.9 


97 
7.1 


105 
8.3 


112 
9.5 


120 
10.6 


128 
11.8 


135 
13.0 


143 
14.2 


150 
15.4 


158 
16.6 


25 66 




25.77 


68 
1.2 


75 
2.4 


83 
3.5 


91 

4.7 


98 
5.9 


106 
7.1 


113 
8.3 


121 
9.5 


129 
10.6 


136 
11.8 


144 
13.0 


151 
14.2 


159 
15.4 


25.77 




25.88 


69 


76 
1.2 


84 
2.4 


92 
3.5 


99 
4.7 


107 
5.9 


114 
7.1 


122 
8.3 


130 
9.5 


137 
10.6 


145 
11.8 


152 
13.0 


160 

14.2 


25.88 




25 99 


1.2 
76 


77 


85 
1.2 


93 
2.4 


100 
3.5 


108 

4.7 


115 
5.9 


123 
7.1 


131 
8.3 


138 
9.5 


146 
10.6 


153 

11.8 


161 
13.0 


25 99 




26 10 


3.4 

84 


1.2 

85 


86 


94 
1.2 


101 
2.4 


109 
3.5 


116 

4.7 


124 
5.9 


132 
7.1 


139 
8.3 


147 
9.5 


154 
10.6 


162 
11.8 


26.10 




26.21 


3.7 
92 


3.4 
93 


1.2 
94 


95 


102 
1.2 


110 
2.4 


117 
3.5 


125 

4.7 


133 
5.9 


140 
7.1 


148 
8.3 


155 
9.5 


163 
10.6 


26.21 




26.32 


4.9 
99 


3.7 
100 


3.4 
101 


1.2 
102 


103 


111 
1.2 


118 

2.4 


126 
3.5 


134 

4.7 


141 
5.9 


149 
7.1 


156 
8.3 


164 
9.5 


26.32 
26 43 




26 43 


6.1 
107 


4.9 
108 


3.7 
109 


3.4 
110 


1.2 
111 


112 


119 
1.2 


127 

2.4 


135 
3.5 


142 

4.7 


150 
5.9 


157 
7.1 


165 
8.3 




26.54 


7.4 
114 


6.1 
115 


4.9 
116 


3.7 
117 


3.4 
118 


1.2 
119 


120 


128 
1.2 


136 
2.4 


143 
3.5 


151 

4.7 


158 
5.9 


166 

7.1 


26.54 




26.65 


8.6 
122 


7.4 
123 


6.1 
124 


4.9 
125 


3.7 
126 


3.4 
127 


1.2 
128 


129 


137 
1.2 


144 
2.4 


152 
3.5 


159 

4.7 


167 
5.9 


26.65 




26.76 


9.8 
130 


8.6 
131 


7.4 
132 


6.1 
133 


4.9 
134 


3.7 
135 


3.4 
136 


1.2 
137 


138 


145 
1.2 


153 
2.4 


160 
3.5 


168 
4.7 


26.76 




26.87 


11.0 
136 


9.8 
137 


8.6 
138 


7.4 
140 


6.1 
141 


4.9 
142 


3.7 
143 


3.4 
144 


1.2 
145 


146 


154 
1.2 


161 
2.4 


169 
3.5 


26.87 




26.98 


12.3 
145 


11.0 
146 


9.8 
147 


8.6 
148 


7.4 
149 


6.1 
150 


4.9 
151 


3.7 
152 


3.4 
153 


1.2 
154 


155 


162 
1.2 


170 
2.4 


26.98 




27 09 


13.5 
152 


12.3 
153 


11.0 
154 


9.8 
155 


8.6 
156 


7.4 
157 


6.1 
158 


4.9 
159 


3.7 
160 


3.4 
161 


1.2 
162 


163 


171 
1.2 


27 09 




27 20 


14.7 
160 


13.5 
161 


12.3 
162 


11.0 
163 


9.8 
164 


8.6 
165 


7.4 
166 


6.1 

167 


4.9 
16S 


3.7 

169 


2.4 
170 


1.2 
171 


172 


27.20 






10.8 


10.9 


11.0 


11.1 


11.2 


11.3 


114 


115 


11.6 


11.7 


11.8 11.9 


12.00 





Compositions op Mixes 



391 



standardizing 
table for ice 
cream mix 
No. 6 testing : 



12.00% Pat 

S.50% M. S. N. F. 

14.00% Sugar 

L .50% Gelatin 

35.00% T. S. 



TABLE 71. 

Basis 1000 pounds of 

mix. 
Top and bottom lines : 

Fat tests. 
Side columns : 

S. N. F. tests. 



In each square: 

Top figure: Pounds butter. 

Center figure: Pounds water. 

Bottom figure: Pounds skim -milk 
powder. 
(Blanks indicate none of kind required.) 





10.0 


10.1 


10.2 

29.7 
19.9 


10.3 


10.4 


10.5 


10.6 


10.7 


10.8 


10 9 


11.0 


11.1 


11 .2 




(A) 
21.50 


32.6 

(F) 

21.2 


31.1 
21.0 


28.2 
19.8 


26.7 
20.6 


25.2 
20.4 


23.8 
20.3 


22.3 
20.1 


20.8 
19.9 


19.3 
19.8 


17.9 
19.7 


16.4 
19.5 


14.9 
19.3 


21.50 


21.57 


32.4 
20.7 


30.9 
20.5 


29.5 
20.3 


28.0 
20.2 


26.5 
20.1 


25.0 
20.0 


23.6 
19.8 


22.1 
19.6 


20.6 
19.4 


19.1 
19.2 


17.7 
19.1 


16.2 
18.9 


14.7 
18.7 


21.57 


21 65 


32.3 
19.8 


30.8 
19.6 


29.3 
19.5 


27.9 
19.4 


26.4 
19.3 


24.9 
19.1 


23.4 
19.0 


22.0 

18.8 


20.5 

18.6 


19.0 
18.5 


17.5 
18.3 


16.1 
18.1 


14.6 
17.9 


21.65 


21.72 


32.2 

18.8 


30.6 
18.6 


29.1 

18.5 


27.7 
18.3 


26.2 
18.1 


24.7 
18.0 


23.3 
17.9 


21.8 
17.8 


20.4 

17.6 


18.9 
17.5 


17.3 
17.3 


15.9 
17.1 


14.4 
17.0 


21 .72 


21 80 


32.0 
17.9 


30.5 
17.7 


29.0 
17.6 


27.6 
17.4 


26.1 
17.3 


24.6 
17.1 


23.2 
17.0 


21.7 
16.8 


20.3 
16.7 


18.7 
16.5 


17.2 
16.3 


15.8 
16.2 


14.3 
16.0 


21.80 


21.87 


31.8 
17.0 


30.3 
16.8 


28.9 
16.7 


27.5 
16.5 


25.9 
16.4 


24.5 
16.3 


23.0 
16.1 


21.5 
15.9 


20.1 
15.8 


18.6 
15.6 


17.0 
15.5 


15.6 
15.3 


14.1 
15.1 


21.87 


21 95 


31.6 
16.1 


30.2 
16.0 


28.8 
15.8 


27.3 
15.6 


25.8 
15.4 


24.3 
15.3 


22.9 
15.1 


21.4 
15.0 


20.0 
14.8 


18.5 
14.7 


16.9 
14.5 


15.5 
14.4 


13.9 
14.2 


21 95 


22 02 


31.5 
15.1 
31.3 
14.2 


30.0 
15.0 


28.6 
14.8 


27.2 
14.7 


25.6 
14.5 


24.2 
14.4 


22.7 
14.3 


21.2 
14.1 


19.8 
14.0 


18.3 
13.8 


16.7 
13.7 


15.3 
13.5 


13.7 
13.3 


22.02 


22 10 


29.9 
14.0 


28.5 
13.9 


27.0 
13.7 


25.5 
13.6 


24.1 
13.4 


22.6 
13.3 


21.1 
13.1 


19.7 
13.0 


18.2 
12.8 


16.5 
12.7 


15.2 
12.5 


13.6 
12.4 


22 10 


22 17 


31.1 
13.3 


29.8 
13.2 


28.3 
13.0 


26.9 

12.8 


25.3 
12.6 


24.0 
12.5 


22.5 
12.3 


20.9 
12.1 


19.6 
11.9 


18.0 
11.8 


16.4 
11.6 


15.0 
11.5 


13.5 
11.3 


22.17 


22 25 


31.0 
12.4 


29.6 
12.2 


28.2 
12.1 


26.8 
11.9 


25.2 
11.8 


23.8 
11.6 


22.3 
11.4 


20.8 
U.3 


19.4 
11.1 


17.8 
11.0 


16.4 
10.8 


14.9 
10.6 


13.3 
10.5 


22.25 


22 32 


30.9 
11.4 


29.5 
11.3 


28.0 
11.2 


26.6 
11,0 


25.0 
10.9 


23.7 
10.7 


22.2 
10.5 


20.6 
10.3 


19.3 
10.1 


17.7 
10.0 


16.2 
9.9 


14.8 
9.7 


13.2 
9.5 


22 32 


22 40 


30.7 
10.5 


29.3 
10.3 


27.9 
10.2 


26.5 
10.0 


24.8 
9.8 


23.5 
9.6 


22.0 
9.5 


20.5 
9.3 


19.1 
9.1 


17.5 
9.0 


16.0 

8.9 


14.6 

8.7 


13.0 

8.6 


22.40 


22.47 
22.55 


30.6 
9.6 


29.1 
9.4 


27.7 
9.3 


26.3 
9.1 


24.6 
9.0 


23.3 
8.9 


21.7 

8.7 


20.3 
8.6 


19.0 

8.4 


17.3 

8.2 


15.9 
8.1 


14.5 
7.9 


12.9 

7.8 


22.47 


30.4 

8.7 


29.0 

8.5 


27.6 

8.4 


26.2 

8.2 


24.5 
8.0 


23.1 

7.9 


21.5 

7.7 


20.2 

7.6 


18.8 
7.4 


17.2 

7.2 


15.8 
7.1 


14.3 
6.9 


12.7 

6.8 


22.55 


22 62 


30.3 

7.7 


28.9 
7.5 


27.4 
7.3 


26.0 
7.1 


24.3 
7.0 


23.0 
6.9 


21.4 
6.7 


20.0 
6.5 


18.6 
6.4 


17.0 
6.2 


15.6 
6.0 


14.2 
5.9 


12.5 

5.8 


22 62 


22 70 
22.77 
22 85 


30.1 

6.8 


28.7 
6.6 


27.3 
6.5 


25.8 
6.4 


24.2 
6.2 


22.8 
6.0 


21.2 
5.9 


19.8 
5.7 


18.4 
5.5 


16.9 
5.4 


15.4 
5.3 


14.0 
5.1 


12.4 
5.0 


22.70 


30.0 
5.9 


28.5 
5.7 


27.1 

5.5 


25.7 
5.4 


24.0 
5.2 


22.6 
5.1 


21.0 
4.9 


19.7 
4.7 


18.2 
4.6 


16.7 
4.5 


15.3 
4.3 


13.8 
4.2 


12.3 
4.0 


22.77 


29.8 
5.0 


28.3 
4.8 


26.9 
4.7 


25.5 
4.5 


23.9 
4.3 


22.5 
4.1 


20.9 
4.0 


19.5 
3.9 


18.0 
3.7 


16.6 
3.5 


15.2 
3.4 


13.7 
3.2 


12.2 
3.1 


22.85 


22 92 


29.7 
4.0 


28.2 
3.8 


26.8 
3.6 


25.3 
3.5 


23.7 
3.4 


22.3 
3.2 


20.7 
3.1 


19.4 
2.9 


17.9 

2.8 


16.4 
2.6 


15.0 
2.5 


13.5 
2.3 


12.0 
2.1 


22 92 


23 00 


29.5 
(E) 
3.1 


28.0 
2.9 


26.6 

2.8 


25.1 
2.6 


23.6 
2.5 


22.1 
2.3 


20.6 
2.2 


19.2 
2.0 


17.7 
1.9 


16.2 
1.7 


14.8 
1.6 


13.3 
1.4 


11.8 
1.2 


23 00 




10 


10.1 


10.2 


10.3 


10.4 


10.5 


10.6 


10.7 


10 8 


10 9 


11.0 


11.1 


11.2 





392 



Ice; Cream Mixes 



standardizing 
table for ice 
cream mix 
No. 6 testing: 



TABLE 71 (Continued). 



12.00% Fat 

8.50% M. S. N. F. 

14.00% Sugar 

.50% Gelatin 



35.00% T. S. 



Basis 1000 ijounds of 

mix. 
Top and bottom lines: 

Tat tests. 
Side columns: 

S. N. F. tests. 



In each square : 
Top figure. Pounds butter. 
Center figure: Pounds water. 
Bottom figure: Pounds skim -milk 
powder. 

(Blanks inilicate none of kind required.) 





10.0 


10 1 


10.2 


10.3 


10.4 


10.5 


10 6 


10.7 


10.8 


10.9 


11.0 


11.1 


11 .2 




23.07 


29.3 
2.2 


27.9 
2.0 


26.4 
1.9 


25.0 
1.7 


23.5 
1.6 


22.0 
1.4 


20.4 
1.3 


19.0 
1.1 


17.5 
1.0 


16.0 
.8 


16.6 

.7 


13.1 
.5 


1.9 
.3 


23.07 


23.15 


29.2 
1.2 


27.7 
1.0 


26.3 
.9 


24.8 
.7 


23.3 
.6 


21.8 
.4 


20.3 
.3 


18.8 
.1 


17.3 
.0 


16.1 

1 


14.8 
2 


13.6 
3 


12.4 
4 


23.15 


23.22 


29.0 
.3 


27.6 
.2 


26.1 
.0 


24.7 
1 


23.5 
2 


22.2 
3 


21.0 
4 


19.8 
5 


18.. 5 
6 


17.3 

7 


16.1 

8 


14.8 
9 


13 6 
10 


23.22 


23.30 


29.6 
3 
(K) 


28.4 
4 


27.2 
5 


25.9 
6 


24.7 
7 


23.5 
8 


22.2 
9 


21.0 
10 


19.8 
11 


18.5 
12 


17.3 
13 


16.1 
14 


14.8 
15 


23.30 


23.37 


30.9 
9 


29.6 
10 


28.4 
11 


27.2 
12 


25.9 
13 


24.7 
14 


23.5 
15 


22.2 
17 


21.0 
18 


19.8 
19 


18.5 
20 


17.3 
21 


16,1 
22 


23.37 


23.45 


32.1 
15 


30.9 
16 


29.6 
17 


28.4 
18 


27.2 
19 


25.9 
20 


24.7 
21 


23.5 
22 


22.2 
24 


21 
25 


19.8 
26 


18.5 
27 


17.3 
28 


23.45 


23.52 


33.3 
21 


32.1 
22 


30.9 
23 


29.6 
24 


28.4 
25 


27.2 
26 


25.9 
27 


24.7 
28 


23.5 
29 


22.2 
30 


21.0 
32 


19.8 
33 


18.5 
34 


23 52 


23 60 


34.6 

28 


33.3 
29 


32.1 
30 


30.9 
31 


29.6 
32 


28.4 
32 


27.2 
33 


25.9 
34 


24.7 
35 


23.5 
36 


22.2 
37 


21.0 
38 


19.8 
40 


23.60 


23.67 


35.8 
34 


34.6 
35 


33.3 
36 


32.1 
37 


30. 9 

38 


29.6 
39 


28.4 
40 


27.2 
41 


25.9 
42 


24.7 
43 


23.5 
44 


22,2 
45 


21.0 
46 


23.67 


23.75 


37.1 
40 


35.8 
41 


34.6 

42 


33.3 
43 


32.1 
44 


30.9 
45 


29.6 
46 


28.4 
47 


27.2 
48 


25.9 
49 


24.7 
50 


23.5 
51 


22.2 
52 


23.75 


23.82 


38.3 
46 


37.1 

47 


35.8 
48 


34.6 
49 


33.3 
50 


32.1 

51 


30.9 
52 


29.6 
53 


28.4 
54 


27.2 
55 


25.9 
57 


24.7 
58 


23.5 
59 


23.82 


23 90 


39.5 
52 


38.3 
53 


37.1 
54 


35.8 
55 


34.6 
56 


33.3 
57 


32.1 
58 


30.9 
59 


29 6 
60 


28.4 
61 


27.2 
62 


25.9 
64 


24.7 
65 


23 90 


23.97 


40.8 
58 


39.5 
59 


38.3 
60 


37.1 
61 


35.8 
62 


34.6 
63 


33.3 
64 


32.1 
65 


30.9 
66 


29.6 
67 


28.4 
68 


27.2 
70 


25.9 
71 


23.97 


24 05 


42.0 
64 


40.8 
65 


39.5 
66 


38.3 
67 


37.1 
68 


35.8 
69 


34.6 
70 


33.3 
71 


32.1 
72 


30.9 
73 


29.6 
74 


28.4 
75 


27,2 
76 


24 05 


24.12 


43.2 
70 


42 

71 


40.8 

72 


39.5 
73 


38.3 
74 


37.1 
75 


35.8 
76 


34.6 

77 


33.3 

78 


32.1 

79 


30.9 
80 


29.6 

81 


28,4 
83 


24 12 


24.20 


44.5 

77 


43.2 

78 


42.0 
79 


40 8 
80 


39.5 
81 


38.3 
82 


37.1 
83 


35.8 
84 


34.6 

85 


33.3 
86 


32.1 

87 


30.9 

88 


29 6 

89 


24 20 


24.27 


45.7 
83 


44.5 
84 


43.2 

85 


42.0 

86 


40.8 

87 


39.5 
88 


38.3 

89 


37.1 
90 


35,8 
91 


34,6 
92 


33.3 
93 


32.1 
94 


30,9 
95 


24 27 


24.35 


46.9 
89 


45.7 
90 


44.5 
91 


43.2 
92 


42.0 
93 


40 8 
94 


39.5 
95 


38.3 
96 


37.1 
97 


35,8 
98 


34,6 

99 


33 3 
100 


32 1 
101 


24.35 


24 42 


48.2 
95 


46.9 
96 


45.7 
97 


44.5 
98 


43.2 
99 


42 
100 


40 8 
101 


39.5 
102 


38.3 
103 


37,1 
104 


35,8 
106 


34 6 
107 


33 3 
108 


24 42 


24 50 


49,4 
101 


48.2 
102 


46.9 
103 


45,7 
104 


44.5 
105 


43.2 
106 


42.0 
107 


40,8 
108 


39.5 
109 


38,3 
110 


37,1 
111 


35.8 
112 


34.6 
113 


24,50 




10 


10 1 


10.2 


10 3 


10 4 


10.5 


10.6 


10 7 


10 8 


10 9 


11 


11 1 


11.2 





Compositions of Mixes 



393 



TABLE 71 (Continued). 



standardizing 
table -for ice 
rream mix 
No. 6 testing: 



12.007(r Fat 

8.50%- M. S. N. F. 

14.00% Sugar 

.50'7r Gelatin 



Sr^OO-rr T. S. 



Basis lonn iiouiids of 

mix. 
Top and bottom lines: 

Fat tests. 
Side columns: 

S. N. F. tests. 



In each square: 

Top figure: Pounds butter. 

Center figure: Pounds water. 

Bottom figure: Pounds skim-mllk 
powder. 
(Bluiiks indicate none of kind required. 





113 


114 


115 


11 6 


11 7 


11 8 


11 9 


12 


12 1 


12 2 


12 3 


12 4 


12.5 


12 6 




21.50 


1,3.4 
19 1 


11.9 
19.0 


10.4 
18.8 


9.0 
18.7 


7.5 
18.5 


6. 1 
18.4 


4.6 
18.3 


3 1 
(D) 
18.1 


1.7 
17.9 


.2 
17.8 


(I) 
6 
18.4 


12 
19.3 


19 
20 


25 
20.9 


21.50 


21.57 


13.2 
18.6 


11.7 
18.4 


10.2 
18.3 


8.9 
18.2 


7.3 
18.0 


5.9 
17.9 


4.4 
17.8 


2.9 
17.6 


1.5 
17.4 


.0 
17.2 


7 
17.7 


13 
18.5 


20 
19.3 


26 
20.0 


21.57 


21 .65 


13.1 
17.8 


11.5 
17.6 


10.1 

17.5 


8.7 
17.3 


7.2 
17.2 


5.8 
17.0 


4.3 

16.8 


2.8 
16.7 


1.4 
16.5 


1 
16.1 


8 
16.9 


13 
17.7 


20 

18.5 


26 
19.3 


21 .65 


21.72 


13.0 
16.8 


11.3 
16.7 


10.0 
16.5 


8.6 

16.4 


7.0 
16.2 


5.7 
16.0 


4.1 
15.9 


2.6 
15.7 


1.2 
15.5 


2 
15.2 


8 
16.1 


14 
16.9 


21 
17.7 


26 
18.5 


21 .72 


21.80 


12.8 
15.9 


11.1 
15.7 


9.8 
15.6 


8.4 
15.5 


6.8 
15.3 


5.5 
15.2 


4.0 
15.0 


2.5 
14.8 


1.1 

14.6 


2 
14.4 


9 
15.2 


15 
16.1 


22 
16.9 


27 
17.7 


21 80 


21 .87 
21 95 


12.6 
15.0 


11.0 

14.8 


9.6 
14.7 


8.3 
14.5 


6.7 
14.4 


5.4 
14.2 


3.8 
14.1 


2.3 
13.9 


9. 
13.7 


3 
13.6 


10 
14.4 


15 
15.2 


22 
16.1 


28 
16.9 


21 87 


12.5 
14.0 


10.9 
13.9 


9.5 
13.7 


8.1 
13.6 


6.6 
13.5 


5.3 
13.3 


3.6 
13.2 


2.2 
13.0 


.8 
12.8 


4 
12.8 


10 
13.6 


16 
14.4 


23 
15.2 


29 
16.1 


21.95 


22 02 


12.3 
13.1 


10.7 
12.9 


9.4 
12.8 


7.9 
12.6 


6.4 
12.5 


5.1 
12.3 


3.4 
12.2 


2.0 
12.0 


.6 
11.8 


4 
12.0 


10 
12.8 


17 
13.6 


24 
14.4 


30 
15.2 


22.02 


22 10 


12.1 
12.2 


10.5 
12.1 


9.2 
11.9 


7.8 
11.8 


6.3 
11 .6 


4.9 
11.5 


3.3 
11.3 


1.9 
11.1 


.5 
10.9 


5 
11.2 


11 
12.0 


17 
12.8 


24 
13.6 


30 
14.4 


22 10 


22.17 


12.0 
11.2 


10.4 
110 


9.1 
10.9 


7.6 
10.8 


6.1 
10.6 


4.8 
10.5 


3.2 
10.3 


1.7 
10.2 


.3 
10.0 


6 
10.4 


11 

11.2 


18 
12.0 


25 
12.8 


31 
13.6 


22.17 


22.25 


11.9 
10.3 


10.2 
10. 1 


8.9 
10.0 


7.5 
9.9 


6.0 
9.8 


4.6 
9.6 


3.0 
9.5 


1.6 
9.3 


.1 
9.1 


6 
9.6 


12 
10.4 


19 
11.2 


26 
12.0 


32 
12.8 


22.25 


22 32 


11.8 
9.4 


10.1 
9.3 


8.8 
9.1 


7.3 
8.9 


5.8 
8.8 


4.5 
8.6 


2.9 

8.5 


1.4 

8.3 


.0 

8.2 


6 

8.8 


13 
9.6 


19 
10.4 


26 
11.2 


32 
12.0 


22.32 


22.40 


11.7 
8.4 


10.0 
8.3 


8.6 
8.1 


7.2 
7.9 


5.6 

7.8 


4.3 

7.7 


2.7 

7.6 


1.2 

7.4 


1 
7.2 


7 
8.0 


14 

8.8 


20 
9.6 


27 
10.4 


33 
11.2 


22.40 


22.47 


11.5 
7.6 


9.9 

7.5 


8.4 
7.3 


7.0 
7.1 


5.5 
7.0 


4.2 
6.8 


2.6 
6.7 


1.1 
6.5 


1 

6.4 


8 
7.2 


14 
8.0 


21 

8.8 


28 
9.6 


34 
10.4 


22.47 


22.55 


11.3 
6.6 


9.7 
6.5 


8.3 
6.3 


6.9 
6.2 


5.3 
6.0 


4.0 
5.9 


2.4 
5.8 


.9 
5.6 


2 
5.6 


8 
6.4 


15 
7.2 


21 
8.0 


28 
8.8 


34 
9.6 


22.55 


22.62 


11.1 
5.6 


9.5 
5.5 


8.2 
5.3 


6.7 
5.2 


5.2 
5.0 


3.7 
4.9 


2.2 

4.8 


.8 
4.6 


3 

4.8 


9 
5.6 


16 
6.4 


22 
7.2 


29 
8.0 


35 

8.8 


22.62 


22.70 


11.0 

4.8 


9.4 
4.7 


8.1 
4.5 


6.6 
4.3 


5.0 
4.2 


3.5 
4.0 


2.0 
3.9 


.6 
3.7 


3 
4.0 


10 

4.8 


16 
5.6 


23 
6.4 


30 

7.2 


36 
8.0 


22.70 


22.77 


10.8 
3.8 


9.2 
3.7 


7.9 
3.5 


6.5 
3.4 


4.9 
3.3 


3.3 
3.1 


1.9 
2.9 


.5 

2.8 


4 
3.2 


10 
4.0 


17 
4.8 


23 
5.6 


30 
6.4 


36 

7.2 


22.77 


22 85 


10.7 
3.0 


9.1 

2.8 


7.7 
2.6 


6.3 
2.5 


4.7 
2.3 


3.2 
2.1 


1.8 
2.0 


.3 
1.8 


5 
2.4 


11 
3.2 


18 
4.0 


24 
4.8 


31 

5.6 


37 
6.4 


22.85 


22 92 


10.5 
2.0 


8.9 

1.8 


7.6 
1.7 


6.1 
1.5 


4.6 
1.4 


3.1 
1.2 


1.6 
1.1 


.2 
.9 


5 
1.6 


12 
2.4 


18 
3.2 


25 
4.0 


32 

4.8 


38 
5.6 


22.92 


23.00 


10.3 
1 .1 


8.8 
.9 


7.4 

.8 


5.9 
.6 


4.4 
.5 


2.9 
.3 


1.4 

.2 


(C) 


6 

.8 


12 
1.6 


19 
2.4 


25 
3.2 


32 
4.0 


38 
4.8 


23 00 




11.3 


11.4 


11.5 


11.6 


11.7 


11.8 


11.9 


12.0 


12.1 


12.2 


12.3 


12.4 


12.5 


12.6 





394 



Ice Cream Mixes 



TABLE 71 (Continued). 



standardizing 
table for ice 
rream mix 
No. 6 testing: 



' 12.00% Fat 

S.50% M. S. N. 

14.007o Susar 

.50% Gelatin 



35.00 



T. S. 



Basis 1000 pounds of 

mix. 
Top and bottom lines: 

Fat tests. 
Side columns; 

S. N. F. tests. 



In eacii square: 

Top figure ; Pounds butter. 

Center figure: Pounds water. 

Bottom figure: Pounds sliim-milk 
powder. 
(Blanlis indicate none of liind required.) 





11 .3 


11.4 


11.5 


11.6 


11.7 


11 8 


11.9 


12.0 


12.1 


12.2 


12.3 


12.4 


12.5 


12.6 




23.07 


9.S 
.2 


8.6 
.0 


7.4 

1 


6.2 
2 


4.9 
3 


3.7 
4 


2.5 
5 


1.2 
6 


7 


13 

.8 


20 
1.6 


26 
2.4 


33 
3.2 


39 
4.0 


23.07 


23 15 


11.1 
5 


9.9 
6 


8.6 

7 


7.4 
8 


6.2 
9 


4.9 
10 


3.7 
11 


2.5 
12 


1.2 
13 


14 


20 

.8 


27 
1.6 


34 

2.4 


40 
3.2 


23.15 


23.22 


12.4 
11 


11.1 
12 


9.9 
13 


8.6 
14 


7.4 
15 


6.2 
16 


4.9 
17 


3.7 
18 


2.5 
19 


1.2 
20 


21 


28 

.8 


34 
1,6 


41 

2.4 


23.22 


23.30 


13.6 
17 


12.4 
19 


11.1 
20 


9.9 
21 


8.6 
22 


7.4 
23 


6.2 
24 


4.9 
25 


3.7 
26 


2.5 

27 


1.2 

28 


29 


35 

1.8 


42 
1.6 


23.30 


23 37 


14.8 
23 


13.6 

24 


12.4 
25 


11.1 

27 


9.9 

28 


8.6 
29 


7.4 
30 


6.2 
31 


4.9 
32 


3.7 
33 


2.5 
34 


1.2 
35 


36 


42 

.8 


23.37 


23.45 


16.1 
29 


14.8 
30 


13.6 
31 


12.4 
32 


11.1 
33 


9.8 
35 


8.6 
36 


7.4 
37 


6.2 
38 


4.9 
39 


3.7 
40 


2.5 
41 


1.2 
42 


43 


23.45 


23.52 


17.3 
35 


16.1 
36 


14.8 
37 


13.6 
38 


12.4 
39 


11.1 
40 


9.9 

42 


8.6 
43 


7.4 
44 


6.2 

45 


4.9 
46 


3.7 
47 


2.5 

48 


1.2 

49 


23.52 


23 60 


18.5 
41 


17.3 
42 


16.1 
43 


14.8 
44 


13.6 

45 


12.4 
46 


11,1 

47 


9.9 

48 


8.6 
50 


7.4 
51 


6.2 
52 


4.9 
53 


3.7 
54 


2.5 
55 


23.60 


23.67 


19.8 
47 


18.5 

48 


17.3 
49 


16.1 
51 


14.8 
52 


13.6 
53 


12.4 
54 


11.1 
55 


9.9 
56 


8.6 
57 


7.4 

58 


6.2 
59 


4.9 
60 


3.7 
61 


23.67 


23.75 


21.0 
'54 


19.8 
55 


18.5 
56 


17.3 
57 


16.1 

58 


14.8 
60 


13.6 
61 


12.4 
62 


11.1 
63 


9.9 
64 


8.6 
65 


7.4 
66 


6.2 
67 


4.9 

68 


23.75 


23.82 


22.2 
60 


21.0 
61 


19.8 
62 


18.5 
63 


17.3 
64 


16.1 
65 


14.8 
67 


13.6 
68 


12.4 
69 


11.1 
70 


9.9 
71 


8.6 
72 


7.4 
73 


6.2 
74 


23.82 


23.90 


23.5 
66 


22.2 
67 


21.0 
68 


19.8 
69 


18.5 
70 


17.3 
71 


16.1 
72 


14.8 
73 


13.6 
75 


12.4 
76 


11.1 

77 


9.9 

78 


8.6 
79 


7.4 
80 


23 90 


23.97 


24.7 
72 


23.5 
73 


22.2 

74 


21.0 
75 


19.8 
76 


18.5 
77 


17.3 
79 


16.1 
80 


14.8 
81 


13.6 

82 


12.4 
83 


11.1 

84 


9.9 

85 


8.6 
86 


23.97 


24.05 


25.9 
77 


24.7 
78 


23.5 
80 


22.2 
81 


21.0 

82 


19.8 
83 


18.5 
84 


17.3 
85 


16.1 

86 


14.8 
87 


13.6 

88 


12.4 
90 


11.1 
91 


9.9 
92 


24.05 


24.12 


27.2 
84 


25.9 
85 


24.7 
86 


23.5 

87 


22.2 

88 


21.0 

89 


19.8 
91 


18.5 
92 


17.3 
93 


16.1 
94 


14.8 
95 


13.6 
96 


12.4 
97 


11.1 
98 


24.12 


24.20 


28.4 
90 


27.2 
91 


25.9 
92 


24.7 
93 


23.5 
94 


22.2 
95 


21.0 
96 


19.8 
97 


18.5 
98 


17.3 
99 


16.1 
101 


14.8 
102 


13.6 
103 


12.4 
104 


24.20 


24.27 


29.6 
96 


28.4 
97 


27.2 
98 


25.9 
100 


24.7 
101 


23.5 
102 


22.2 
103 


21.0 
104 


19.8 
105 


18.5 
106 


17.3 
107 


16.1 
108 


14.8 
109 


13.6 
110 


24.27 


24.35 


30.9 
102 


29.6 
103 


28.4 
104 


27.2 
105 


25.9 
106 


24.7 
107 


23.5 
108 


22.2 
109 


21.0 
111 


19.8 
112 


18.5 
113 


17.3 
114 


16.1 
116 


14.8 
117 


24.35 


24.42 


32.1 
109 


30.9 
110 


29.6 
111 


28.4 
112 


27.2 
113 


25.9 
114 


24.7 
115 


23.5 
116 


22.2 
117 


21.0 
118 


19.8 
119 


18.5 
120 


17.3 
121 


16.1 
122 


24.42 


24 50 


33.3 
114 


32.1 
116 


30.9 
117 


29.6 
118 


28.4 
119 


27.2 
120 


25.9 
121 


24.7 
122 


23.5 
123 


22.2 
124 


21 .0 
125 


19.8 
126 


18.5 
127 


17.3 
128 


24.50 




11.3 


114 


11.5 


11 6 


11.7 


11 .8 


11 .9 


12.0 


12.1 


12.2 


12.3 


12.4 


12.5 


12.6 





Compositions of Mixiis 



395 



TABLE 71 (Continued). 



standardizing 
table for ice 
cream mix 
No. 6 testing: 



12.00 

8.50 

14.00 

.50 



% Fat 

% M. S. N. 

9c Susar 

% Gelatin 



SS.OOTf T. S. 



Basis 1000 pounds of 

mix. 
Top and bottom lines: 

Fat tests. 
Side columns: 

S. N. F. tests. 



In each square: 

Top figure: Pounds butter. 

Center figure: Pounds water. 

Bottom figure: Pounds skim-milk 
powder. 
(Blanks indicate none of kind roijuireil. I 





12.7 


12.8 


12.9 


13.0 


13.1 


13.2 


13.3 


13.4 


13.5 


13.6 


13.7 


13.8 


13 9 


14.0 




21 50 


32 
21.7 


38 
22.5 


45 
23.2 


51 
24.1 


58 
24.9 


64 
25.7 


71 
26.5 


77 
27.3 


84 
28.1 


90 
28.9 


97 
29.7 


103 
30.5 


110 
31.3 


(H) 

116 

32.1 


21.50 


21 .57 


33 
20.9 


39 
21.7 


46 
22.5 


52 
23.2 


59 
24.1 


65 
24.9 


72 
25.7 


78 
26.5 


85 
27.3 


91 
28.1 


98 
28.9 


104 

29.7 


111 
30.5 


117 
31.3 


21.57 


21.65 


33 
20.0 


39 
20.9 


46 
21.7 


52 
22.5 


59 
23.2 


65 
24.1 


72 
24.9 


78 
25.7 


85 
26.5 


91 
27.3 


98 
28.1 


104 

28.9 


111 
29.7 


117 
30.5 


21.65 


21 .72 


33 
19.3 


39 
20.0 


46 
20.9 


53 
21.7 


60 
22.5 


66 
23.2 


73 
24.1 


79 
24.9 


86 
25 . 7 


92 
26.5 


99 
27.3 


105 
28.1 


112 

28.9 


US 
29.7 


21 .72 


21 80 


34 

18.5 


40 
19.3 


47 
20.0 


54 
20 9 


61 
21.7 


67 
22.5 


74 
23.2 


80 
24.1 


87 
24.9 


93 
25.7 


100 
26.5 


106 
27.3 


113 
28.1 


119 

28.9 


21 80 


21 87 


35 
17.7 


41 
18.5 


48 
19.3 


54 
20.0 


61 
20.9 


67 
21.7 


74 
22.5 


SO 
23.2 


87 
24.1 


93 
24.9 


100 
25.7 


106 
26.5 


113 
27.3 


119 
28.1 


21.87 


21 95 


36 
16.9 


42 
17.7 


49 
18.5 


55 
19.3 


62 
20.0 


68 
20.9 


75 
21.7 


81 
22.5 


88 
23.2 


94 
24.1 


101 
24.9 


107 
25.7 


114 
26.5 


120 
27.3 


21 95 


22 02 


37 
16.1 


43 
16.9 


50 
17.7 


56 
18.5 


63 
19.3 


69 
20.0 


76 
20.9 


82 
21.7 


89 
22.5 


95 
23.2 


102 
24.1 


108 
24.9 


115 
25.7 


121 
26.5 


22 02 


22 10 


37 
15.2 


43 
16.1 


50 
16.9 


56 
17.7 


63 
18.5 


69 
19.3 


76 
20.0 


82 
20.9 


89 
21.7 


95 
22.5 


102 
23.2 


108 
24.1 


115 
24.9 


121 
25.7 


22 10 


22 17 


38 
14.4 


44 
15.2 


51 
16.1 


57 
16.9 


64 
17.7 


70 
18.5 


77 
19.3 


83 
20.0 


90 
20.9 


96 
21.7 


103 
22.5 


109 
23.2 


116 
24.1 


122 
24.9 


22.17 


22.25 


39 
13.6 


45 
14.4 


52 
15.2 


58 
16.1 


65 
16.9 


71 

17.7 


78 
18.5 


84 
19.3 


91 
20.0 


97 
20.9 


104 
21.7 


110 
22.5 


117 
23.2 


123 
24.1 


22.25 


22.32 


39 

12.8 


45 
13.6 


52 
14.4 


58 
15.2 


65 
16.1 


71 
16.9 


78 
17.7 


84 
18.5 


91 
19.3 


97 
20.0 


104 
20.9 


110 
21.7 


117 
22.5 


123 
23.2 


22.32 


22.40 


40 
12.0 


46 
12.8 


53 
13.6 


59 
14.4 


66 
15.2 


72 
16.1 


79 
16.9 


85 
17.7 


92 
18.5 


98 
19.3 


105 
20.0 


111 
20.9 


118 
21.7 


124 
22.5 


22 40 


22 47 


41 
11.2 


47 
12.0 


54 
12.8 


60 
13.6 


67 
14.4 


73 
15.2 


80 
16.1 


86 
16.9 


93 
17.7 


99 
18.5 


106 
19.3 


112 
20.0 


119 
20.9 


125 

21.7 


22.47 


22.55 
22 62 


41 
10.4 


47 
11.2 


54 
12 


60 

12.8 


67 
13.6 


73 
14.4 


80 
15.2 


86 
16.1 


93 
16.9 


99 
17.7 


106 
IS. 5 


112 
19.3 


119 
20.0 


125 
20.9 


22.55 


42 
9.6 


48 
10.4 


55 
11.2 


61 
12.0 


68 
12.8 


74 
13.6 


81 
14.4 


87 
15.2 


94 
16.1 


100 
16.9 


107 
17.7 


113 
18.5 


120 
19.3 


126 
20.0 


22 62 


22 70 


43 

8.8 


49 
9.6 


56 
10.4 


62 
11.2 


69 
12.0 


75 
12.8 


82 
13.6 


88 
14.4 


95 
15.2 


101 
16.1 


108 
16.9 


114 
17.7 


121 
18.5 


127 
19.3 


22 70 


22.77 


43 
8.0 


49 
8.8 


56 
9.6 


62 
10.4 


69 
11.2 


75 
12.0 


82 
12.8 


88 
13.6 


95 
14.4 


101 
15.2 


108 
16.1 


114 
16.9 


121 
17.7 


127 
18.5 


22 77 


22.85 


44 

7.2 


50 
8.0 


57 
8.8 


63 
9.6 


70 
10.4 


76 
11.2 


83 
12.0 


89 
12.8 


96 
13.6 


102 
14.4 


109 
15.2 


115 
16.1 


122 
16.9 


128 
17.7 


22 85 


22 92 


45 
6.4 


51 
7.2 


58 
8.0 


64 

8.8 


71 

9.6 


77 
10.4 


84 
11.2 


90 
12.0 


97 
12.8 


103 
13.6 


110 
14.4 


116 
15.2 


123 
16.1 


129 
16.9 


22 92 


23.00 


45 
5.6 


51 

6.4 


58 
7.2 


64 
8.0 


71 

8.8 


77 
9.6 


84 
10.4 


90 
11.2 


97 
12.0 


103 

12.8 


110 

13.6 


116 
14.4 


123 
15.2 


129 
16.1 


23 00 




12.7 


12.8 


12 9 


13 


13.1 


13.2 


13.3 


13.4 


13.5 


13.6 


13.7 


13.8 


13.9 


14.0 





396 



Ice CRii:AM Mixes 



standardizing 
table for ice 
cream mix 
No. 6 testing: 



TABLE 71 (Continued). 



12.00% Fat 

8.50% M. S. N. F. 
14.00% Sugar 
.50% Gelatin 



35.00% T. S. 



Basis 1000 DouuUs of 

ml.x. 
Top and bottom lines: 

Fat tests. 
Side columns: 

S. N. F. tests. 



In each square: 

Top tlgure: Pounds buttei-. 

Center figure: Pounds water. 

Bottom figure: Pounds slcim-mlll? 
powder. 
(Blanlis indicate none of liind required.) 





12 7 


12.8 


12 9 


13 


13.1 


13 2 


13.3 


13.4 


13 5 


13 6 


13.7 


13.8 


13 9 


14.0 




23.07 


46 

4.8 


52 
5.6 


59 
6.4 


65 

7.2 


72 
8.0 


79 
8.8 


85 
9.6 


91 
10.4 


98 
11.2 


104 
12.0 


111 
12.8 


117 
13.6 


124 
14.4 


130 
15.2 


23.07 


23.15 


47 
4.0 


53 

4.8 


60 
5.6 


66 
6.4 


73 
7.2 


80 
8.0 


86 
8.8 


92 
9.6 


99 
10.4 


105 
11.2 


112 
12.0 


118 

12.8 


125 
13.6 


131 
14.4 


23.15 


23.22 


47 
3.2 


53 
4.0 


60 

4.8 


67 
5.6 


74 
6.4 


81 
7.2 


87 
8.0 


93 

8.8 


100 
9.6 


106 
10.4 


113 
11.2 


119 
12.0 


126 
12.8 


132 
13.6 


23.22 


23.30 


47 
2.4 


54 
3.2 


61 
4.0 


67 

4.8 


74 
5.6 


81 
6.4 


87 
7.2 


93 
8.0 


100 

8.8 


106 
9.6 


113 
10.4 


119 
11.2 


126 
12 


132 

12.8 


23.30 


23.37 


48 
1.6 


55 
2.4 


61 
3.2 


68 
4.0 


74 
4.8 


82 
5.6 


88 
6.4 


94 

7.2 


101 

8.0 


107 

8.8 


114 

9.6 


120 
10.4 


127 
11.2 


133 
12.0 


23.37 


23 45 


49 
1.8 


56 
1.6 


62 

2.4 


69 
3.2 


75 
4.0 


82 

4.8 


89 
5.6 


95 
6.4 


102 

7.2 


108 
8.0 


115 

8.8 


121 
9.6 


128 
10.4 


134 
11.2 


23 45 


23.52 


50 


56 

.8 


63 
1.6 


69 
2.4 


75 
3.2 


83 
4.0 


89 
4.8 


96 
5.6 


103 
6.4 


109 

7.2 


116 
8.0 


122 

8.8 


128 
9.6 


134 
10.4 


23.52 


23.62 


1.2 
56 


57 


63 

.8 


70 
1.6 


76 

2.4 


83 
3.2 


90 
4.0 


96 

4.8 


103 
5.6 


109 
6.4 


117 
7.2 


123 
8.0 


129 

8.8 


135 
9.6 


23 62 


23.67 


2.5 
62 


1.2 
63 


64 


71 

.8 


77 
1.6 


81 
2.4 


90 
3.2 


97 
4.0 


104 

4.8 


110 
5.6 


117 
6.4 


123 
7.2 


129 
8.0 


136 

8.8 


23 67 


23.75 


3.7 
69 


2.5 
70 


1.2 
71 


72 


78 
.8 


85 
1.6 


91 
2.4 


97 
3.2 


104 
4.0 


111 

4.8 


118 
5.6 


124 
6.4 


130 
7.2 


136 
8.0 


23 75 


23.82 


4.9 
75 


3.7 
76 


2.5 

77 


1.2 

78 


79 


85 
.8 


91 
1.6 


98 
2.4 


105 
3.2 


111 
4.0 


118 

4.8 


125 
5.6 


131 

6.4 


137 
7.2 


23.82 


23 90 


6.2 
81 


4.9 
82 


3.7 
83 


2.5 

84 


1.2 
85 


86 


92 

.8 


98 
1.6 


105 

2.4 


112 
3.2 


119 
4.0 


125 

4.8 


131 
5.6 


138 
6.4 


23 90 


23.97 


7.4 
87 


6.2 

88 


4.9 
89 


3.7 
90 


2.5 
91 


1.2 
92 


93 


99 
.8 


106 
1.6 


112 
2.4 


120 
3.2 


126 
4.0 


132 

4.8 


138 
5.6 


23 97 


24.05 


8.6 
93 


7.4 
94 


6.2 
95 


4.9 
96 


3.7 

97 


2.5 
98 


1.2 

99 


100 


106 

.8 


113 
1.6 


121 
2.4 


126 
3.2 


133 
4.0 


139 

4.8 


24 05 


24.12 
24 20 


9.9 
99 


8.6 
100 


7.4 
101 


6.2 
102 


4.9 
103 


3.7 
104 


2 5 
105 


1.2 
106 


107 


113 

.8 


121 
1.6 


127 
2.4 


134 
3.2 


140 
4.0 


24 12 


11 
105 


9.9 
106 


8.6 
107 


7.4 
108 


6.2 
109 


4.9 
110 


3.7 
HI 


2.5 
112 


1.2 
113 


114 


122 

.8 


127 
1.6 


134 
2.4 


140 
3.2 


24 20 


24.27 


12.4 
111 


11.1 
112 


9.9 
113 


8.6 

lis 


7.4 
116 


6 2 
117 


4.9 
118 


3.7 
119 


2.5 
120 


1.2 
121 


122 


128 

.8 


135 
1.6 


141 
2.4 


24.27 


24.35 


13.6 
118 


12.4 
119 


11.1 
120 


9.9 
121 


8.6 
122 


7.4 
123 


6.2 
124 


4.9 
125 


3.7 
126 


2.5 
127 


1.2 

128 


129 


135 

.8 


142 
1.6 


24 35 


24.42 


14.8 
123 


13.6 
125 


12.4 
126 


11.1 
127 


9.9 
128 


8.6 
129 


7.4 
130 


6.2 
131 


4.9 
132 


3.7 
133 


2.5 
134 


1.2 
135 


136 


142 

.8 


24 42 


24.50 


16.1 
130 


14.8 
131 


13.6 
132 


12.4 
133 


11.1 
134 


9.9 
135 


8.6 
136 


7.4 
137 


6.2 
138 


4.9 
139 


3.7 
140 


2.5 
141 


1.2 
142 


(G) 
143 


24 50 




12 7 


12.8 


12.9 


13 


13 1 


13.2 


13.3 


13 4 13 5 


13 6 


13.7 


13.8 


13.9 


14.0 





Compositions op Mixes 



397 



standardizing 
table for ice 
cream mix 
No. 7 testing: 



12.00% Pat 
9.50% M. S. N. F 
14.00% SuKar 
.50% Gelatin 



36.00% T. S. 



TABLE 72. 

Hasis 1000 pouiid.s of 

mi.\. 
Top and Ijottom lines : 

Fat tests. 
Side columns : 

S. N. F. tests. 



22 33 



In each stiuare: 
Top tigure : Pounds butter 
Centei figure: Pounds water. 
Bottom figure: Pounds slclm-mlllt 
powder. 

(Blanks indicate none of kind requiied. ) 




23 28 



23.41 



23 49 



23 66 



23 75 



398 



Ice Cream Mixes 



StandardUing 
table for ice 
cream mix 
No. 7 testing: 



TABLE 72 (Continued). 



00% 
50% 
00% 
,50% 



Fat 

M. S. N. F. 

Sugar 

Gelatin 



36.00% T. S. 



Basis 1000 pounds of 

mix. 
Top and bottom lines : 

Fat tests. 
Side columns ; 

S. N. F. tests. 



In each sauare : 

Top figure: Pounds butter. 

Ceiiter figure; Pounds water. 

Bottom figure: Pounds skim -milk 
powder. 
(Blanks Indicate none of kind required.) 





10.0 


10.1 


10 2 


10 3 


10.4 


10.5 


10.6 


10.7 


10.8 


10.9 


11.0 


111 


112 




24.08 


29.4 
2.6 


27.9 
2.4 


26.5 
2.2 


25.0 
2.0 


23.5 
1.8 


22.0 
1.6 


20.5 
1.4 


19.1 
1.2 


17.fi 
1.1 


16.1 
1.0 


14.6 

.8 


13.2 

.7 


11.7 
.5 


24 08 


24.16 


29.2 
1.6 


27.7 
1.4 


26.3 
1.2 


24.8 
1.0 


23.3 

.8 


21.8 
.6 


20.3 
.4 


18.9 
.2 


17.4 
.1 


15.9 
.0 


14.8 
1 


13.5 
2 


12.3 
3 


24.16 


24.24 


29.0 
.5 


27.5 
.3 


26.1 
.1 


24.7 
.0 


23.4 
1 


22.2 
2 


21.0 
3 


19.7 

4 


18.5 
5 


17.3 
6 


16.0 

7 


14.8 
8 


13.5 
9 


24.24 


24.33 


29.6 
3 


28.4 
4 


27.1 
5 


25.9 
6 


24.7 

7 


23.4 

8 


22.2 
10 


21.0 
11 


19.7 
12 


18.5 
13 


17.3 
14 


16.0 
15 


14.8 
16 


24.33 


24.41 


30.8 
9 


29.6 
10 


28.4 
11 


27.1 
12 


25.9 
13 


24.7 
14 


23.4 
15 


22.2 
17 


21.0 
18 


19.7 
19 


18.5 
20 


17.3 
21 


16.0 
22 


24.41 


24.49 


32.1 
15 


30.8 
16 


29.6 
17 


28.4 

18 


27.1 
19 


25.9 
20 


24.7 
21 


23.4 
22 


22.2 
24 


21.0 
25 


19.7 
26 


18.5 
27 


17.3 

28 


24.49 


24.58 


33.3 
21 


32.1 
22 


30.8 
23 


29.6 
24 


28.4 
25 


27.1 
26 


25.9 
27 


24.7 
28 


23.4 
29 


22.2 
31 


21.0 
32 


19.7 
33 


18.5 
34 

t 


24.58 


24 66 


34.5 
27 


33.3 

28 


32.1 
29 


30.8 
30 


29.6 
31 


28.4 
32 


27.1 
33 


25.9 
34 


24.7 
35 


23.4 
36 


22.2 
38 


21.0 
39 


19.7 
40 


24 66 


24.74 


35.7 
33 


34.5 
34 


33.3 
35 


32.1 
36 


30.8 
37 


29.6 
38 


28.4 
39 


27.1 
40 


25.9 
41 


24.7 
42 


23.4 
43 


22.2 
45 


21 

46 


24.74 


24.83 


37.0 
39 


35.7 
40 


34.5 
41 


33.3 
42 


32.1 
43 


30.8 

44 


29.6 
45 


28.4 
47 


27.1 
48 


25.9 
49 


24.7 
51 


23.4 
52 


22.2 
53 


24.83 


24.91 


38.2 
46 


37.0 
47 


35.7 

48 


34.5 
49 


33.3 
50 


32.1 
51 


30.8 
52 


29.6 
53 


28.4 
54 


27.1 
55 


25.9 
56 


24.7 
57 


23.4 
58 


24.91 


24.99 


39.4 
52 


38.2 
53 


37.0 

54 


35.7 
55 


34.5 
56 


33.3 
57 


32.1 

58 


30.8 
59 


29.6 
60 


28.4 
61 


27.1 
62 


25.9 
63 


24.7 
64 


24.99 


25.07 


40.7 
58 


39.4 
59 


38.2 
60 


37.0 
61 


35.7 
62 


34.5 
63 


38.3 
64 


32.1 
65 


30.8 
66 


29.6 
67 


28.4 
68 


27.1 
69 


25.9 
70 


25.07 


25.16 


41.9 
64 


40.7 
65 


39.4 
66 


38.2 
67 


37.0 
68 


35.7 
69 


34.5 
70 


33.3 

71 


32.1 
72 


30.8 
73 


29.6 
74 


28.4 
75 


27.1 
76 


25 16 


25.24 


43.2 
70 


41.9 
71 


40.7 
72 


39.4 

73 


38.2 
74 


37.0 
75 


35.7 
76 


34.5 

77 


33.3 

78 


32.1 

79 


30.8 
80 


29.6 
81 


28.4 
82 


25 24 


25.33 


44.4 
76 


43.2 

77 


41.9 

78 


40.7 
79 


39.4 
80 


38.2 
81 


37.0 

82 


35.7 
83 


34.5 

84 


33.3 

86 


32.1 

87 


30.8 

88 


29.6 
89 


25 33 


25.41 


45.6 

82 


44.4 
83 


43 2 

84 


41.9 

85 


40.7 
86 


39.4 

87 


38.2 
88 


37.0 
89 


35.7 
90 


34.5 
92 


33.3 
93 


32.1 
94 


30.8 
95 


25.41 


25 49 


46.8 
88 


45.6 
89 


44.4 
90 


43.2 
91 


41.9 
92 


40.7 
93 


39.4 
94 


38.2 
95 


37.0 
96 


35.7 
97 


34.5 
98 


33.3 
10 


32.1 
101 


25 49 


25.58 


48.1 
94 


46.8 
95 


45.6 
96 


44.4 
97 


43.2 
98 


41.9 
99 


40.7 
100 


39.4 
101 


38. 2 
102 


37.0 
103 


35.7 
104 


34.5 
106 


33.3 
107 


25.58 


25 66 


49.3 
100 


48.1 
101 


46.8 
102 


45.6 
103 


44.4 
104 


43.2 
105 


41.9 
106 


40.7 
107 


39.4 
108 


38.2 
109 


37.0 
110 


35.7 
111 


34.5 
112 


25 66 




10 


10.1 


10 2 


10.3 


10 4 


10.5 


10 6 


10 7 


10.8 


10 9 


11.0 


111 


11.2 





standardizing 
table for ice 
cream mix 
No. 7 testing: 



12.00% Fat 
9.507o M. S. N F 
14.00ff Sugar 
.50% Gelatin 



Compositions of Mixes 
TABLE 72 (Continued). 



399 



36.00%, T. S. 



Basis 1000 pounds of 

mix. 
Top and bottom lines' 

Fat tests. 
Side columns: 

S. N. F. tests. 



In eacti square: 
Top figure: Pounds butter 
Center figure: Pounds water 
Bottom figure: Pounds skim-railk 
powder. 

(Blanks indicate none of kind required.) 




400 



Ice Cream Mixes 



standardizing 
table for ice 
cream mix 
No. 7 testing: 



TABLE 72 (Continued). 



12.00% Fat 
9.50% M. S. N. F. 
14.00% Sugar 
..50% Gelatin 



.36.00% T. S. 



Basis 1000 pouiKis nf 

mix. 
Top and bottom Unes: 

Fat tests. 
Side columns: 

S. N. F. tests. 



In each sfiuare: 

Top figure: Pounds butter. 

Center figure: Pounds water. 

Bottom figure: Pounds skim -milk 
powder. 
(Blanks intiicate none of kind required.) 





11.3 


11.4 


11 5 


11.6 


11.7 


11 .8 


119 


12.0 


12.1 


12.2 


12.3 


12 4 


12.5 


12.6 




24.08 


10.2 
.3 


8.7 
.1 


7.4 

1 


6.2 
2 


4.9 
3 


3.7 
4 


2.5 
6 


1.2 
6 


7 


13 

.9 


19 
1.8 


26 
2.7 


33 
3.6 


39 
4.5 


24.08 


24.16 


11.1 
4 


9.9 
5 


8.6 
6 


7.4 

7 


6.2 

8 


4.9 
9 


3.7 
10 


2.5 
1.2 


1.2 
13 


14 


20 
.9 


27 
1.8 


33 

2.7 


40 
3.6 


24.16 


24.24 


12. 3 
10 


11.1 
12 


9.9 
13 


8.6 
14 


7.4 
15 


6.2 
16 


4.9 
17 


3.7 
18 


2.5 
19 


1.2 
20 


21 


28 
.9 


34 
1.8 


40 

2.7 


24.24 


24.33 


13.5 
18 


12.3 
19 


11.1 
20 


9.9 
21 


8.6 
22 


7.4 
23 


6.2 

24 


4.9 
25 


3.7 
26 


2.5 
27 


1.2 

28 


29 


35 
.9 


41 
1.8 


24.33 


24 41 


14.8 
23 


13.5 
24 


12.3 
26 


11.1 
27 


9.9 
28 


8.6 
29 


7.4 
30 


6.2 
31 


4.9 
32 


3.7 
33 


2.5 
34 


1.2 
35 


36 


42 
.9 


24 41 


24.49 


16.0 

29 


14.8 
30 


13.5 
31 


12.3 
33 


U.l 
34 


9.9 
35 


8.6 
36 


7.4 
37 


6.2 

38 


4.9 
39 


3.7 
40 


2.5 
41 


1.2 

42 


43 


24.49 


24.58 


17.3 
35 


16.0 
36 


14.8 
37 


13.5 
38 


12.3 
40 


111 
42 


9.9 
43 


8.6 
44 


7.4 
45 


6.2 
46 


4.9 
47 


3.7 
47 


2.5 

48 


1.2 
49 


24.58 


24.66 


18.5 
41 


17.3 
42 


16.0 
43 


14.8 
44 


13.5 
45 


12.3 

47 


11.1 

48 


9.9 
49 


8.6 
50 


7.4 
51 


6.2 
52 


4.9 
53 


3.7 
54 


2.5 
55 


24.66 


24.74 


19.7 
47 


18.5 
48 


17.3 
49 


16.0 
50 


14.8 
51 


13.5 
52 


12.3 
54 


11. 1 
56 


9.9 
57 


8.6 

58 


7.4 
59 


6.2 
60 


4.9 
61 


3.7 
62 


24.74 


24.83 


21.0 

54 


19.7 
55 


18.5 
56 


17.3 
57 


16.0 

58 


14.8 
59 


13.5 
61 


12.3 
62 


11.1 

63 


9.9 
64 


8.6 
65 


7.4 
66 


6.2 
67 


4.9 

68 


24 83 


24.91 


22.2 
59 


21.0 
61 


19.7 
62 


18.5 
63 


17.3 
64 


16.0 
65 


14.8 
66 


13.5 
67 


12.3 
68 


11.1 
70 


9.9 
71 


8.6 
72 


7.4 
73 


6.2 
74 


24.91 


24.99 


23.4 
65 


22.2 
67 


21.0 
68 


19.7 
69 


18.5 
70 


17.3 
71 


16.0 
72 


14.8 
73 


13.5 

74 


12.3 
76 


U.l 

77 


9.9 

78 


8.6 
79 


7.4 
80 


24.99 


25.07 


24.7 
71 


23.4 

72 


22.2 

74 


21.0 
75 


19.7 
76 


18.5 
77 


17.3 

78 


16.0 
79 


14.8 
80 


13.5 
81 


12.3 
83 


11.1 

84 


9.9 
85 


8.6 
86 


25.07 


25 16 


25.9 

77 


24.7 
78 


23.4 
79 


22.2 
81 


21.0 

82 


19.7 
83 


18.5 
84 


17.3 

85 


16.0 
86 


14.8 
87 


13.5 
88 


12.3 
90 


U.l 
91 


9.9 
92 


25.16 


25.24 


27.1 
83 


25.9 

84 


24.7 
85 


23.4 

87 


22.2 

88 


21.0 

89 


19.7 
90 


18.5 
91 


17.3 
92 


16.0 
93 


14.8 
94 


13.5 
96 


12.3 
97 


U.l 

98 


25.24 


25.33 


28.4 
90 


27.1 
91 


25.9 
92 


24.7 
93 


23.4 
94 


22.2 
96 


21.0 
97 


19.7 
98 


18.5 
99 


17.3 
100 


16.0 
101 


14.8 
102 


13.5 
103 


12.3 
105 


25.33 


25.41 


29.6 
96 


28.4 
97 


27.1 
98 


25.9 
99 


24.7 
100 


23.4 
101 


22.2 
102 


21 
103 


19.7 
104 


18.5 
105 


17.3 
106 


16.0 
107 


14.8 
109 


13.5 
110 


25.41 


25.49 


30.8 
102 


29.6 
103 


28.4 
104 


27.1 
105 


25.9 
106 


24.7 
107 


23.4 
109 


22.2 
110 


21.0 
111 


19.7 
112 


18.5 
113 


17.3 
114 


16.0 
115 


14.8 
116 


25.49 


25.58 


32.1 
108 


30.8 
109 


29.6 
110 


28.4 
111 


27.1 
112 


25.9 
113 


24.7 
114 


23.4 
116 


22.2 
117 


21.0 
118 


19.7 
119 


18.5 
120 


17.3 
121 


16.0 
122 


25.58 


25 66 


33.3 
114 


32.1 
116 


30.8 
116 


29.6 
117 


28.4 
118 


27.1 
119 


25.9 
120 


24.7 
121 


23,4 
122 


22.2 
124 


21.0 
125 


19.7 
126 


18.5 
127 


17.3 
128 


25.66 




11 .3 


11.4 


11.5 


11.6 


11.7 


11. a 


11.9 


12.0 


12.1 


12.2 


12.3 


12.4 


12.5 


12 6 





Compositions of Mixes 



401 



TABLE 72 (Continued). 





( 12.009^ 


Pat 


Uasis 1000 Douiuls of 


standardizing 


1 9.50% 


M. S. N. F. 


mix. 


table for ice 


1 14.00% 
I .50% 


Sugar 


Top and bottom lines: 


cream mix 


GelaUn 


Fat tests. 


No. 7 testing: 






Side columns : 




36.00% 


T. S. 


S. N. F. tests. 



In each square : 

Top figure : Pounds butter. 

Center figure: Pounds water. 

Bottom figure: Pounds sklm-rallk 
powder. 
(Blanks indicate none of kind renuired. ) 





12.7 


12 8 


12.9 


13.0 


13.1 


13.2 


13.3 


13.4 


13.5 


13.6 


13.7 


13.8 


13.9 


14.0 




22.33 


29 
24.1 


35 
25.0 


42 
25.9 


48 
26.8 


54 

27.7 


61 
28.6 


67 
29.5 


74 
30.4 


80 
31.3 


86 
32.2 


93 
33.1 


99 
33.9 


106 
34.5 


112 
35.7 


22.33 


22.41 


30 
23.2 


36 
24.1 


43 
25.0 


49 
25.9 


55 
26.8 


62 

27.7 


68 
28.6 


75 
29.5 


81 
30.4 


87 
31.3 


94 
32.2 


100 
33.1 


107 
33.9 


113 
34.8 


22.41 


22.50 


31 
22.3 


37 
23.2 


44 
24.1 


50 
25.0 


56 
25.9 


63 
26.8 


69 

27.7 


76 
28.6 


82 
29.5 


88 
30.4 


95 
31.3 


101 
32.2 


108 
33.1 


114 

33.9 


22.50 


22.58 


31 
21.4 


37 
22.3 


44 
23.2 


50 
24.1 


56 
25.0 


63 
25.9 


69 
26.8 


76 
27.7 


82 
28.6 


88 
29.5 


95 
30.4 


101 
31.3 


108 
32.2 


115 
33.1 


22.58 


22.66 


32 
20.6 


38 
21.4 


45 
22.3 


51 

23.2 


57 
24.1 


64 
25.0 


70 
25.9 


77 
26.8 


83 

27.7 


89 
28.6 


96 
29.5 


102 
30.4 


109 
31.3 


115 

32.2 


22.66 


22.75 


33 
19.7 


39 
20.6 


46 
21.4 


52 
22.3 


58 
23.2 


65 
24.1 


71 
25.0 


78 
25.9 


84 
26.8 


90 

27.7 


97 
28.6 


103 

29.5 


110 
30.4 


116 
31.3 


22.75 


22.83 


34 

18.8 


40 
19.7 


47 
20.6 


53 
21.4 


59 
22.3 


66 
23.2 


72 
24.1 


79 
25.0 


85 
25.9 


91 
26.8 


98 
27.7 


104 

28.6 


111 

29.5 


117 
30.4 


22.83 


22.91 


34 
17.9 


40 

18.8 


47 
19.7 


53 
20.6 


59 
21.4 


66 
22.3 


72 
23.2 


79 
24.1 


85 
25.0 


91 
25.9 


98 
26.8 


104 

27.7 


111 

28.6 


118 
29.5 


22.91 


23.00 


35 
17.0 


41 
17.9 


48 
18.8 


54 
19.7 


60 
20.6 


67 
21.4 


73 
22.3 


80 
23.2 


86 
24.1 


92 
25.0 


99 
25.9 


105 
26.8 


112 
27.7 


119 

28.6 


23.00 


23.08 


36 
16.1 


42 
17.0 


49 
17.9 


55 

18.8 


61 
19.7 


68 
20.6 


74 
21.4 


81 
22.3 


87 
23.2 


93 
24.1 


100 
25.0 


106 
25.9 


113 
26.8 


119 

27.7 


23.08 


23.16 


37 
15.2 


43 
16.1 


50 
17.0 


56 
17.9 


62 

18.8 


69 
19.7 


75 
20.6 


82 
21.4 


88 
22.3 


94 
23.2 


101 
24.1 


107 
25.0 


114 
25.9 


120 

26.8 


23.16 


23.25 


38 
14.3 


44 
15.2 


61 
16.1 


57 
17.0 


63 
17.9 


70 

18.8 


76 
19.7 


83 
20.6 


89 
21.4 


95 
22.3 


102 
23.2 


108 
24.1 


115 
25.0 


121 
25.9 


23.25 


23.33 


38 
13.4 


44 
14.3 


51 
15.2 


57 
16.1 


63 
17.0 


70 
17.9 


76 

18.8 


83 
19.7 


89 
20.6 


95 
21.4 


102 
22.3 


108 
23.2 


115 
24.1 


122 
25.0 


23.33 


23.41 


39 
12.5 


45 
13.4 


52 
14.3 


58 
15.2 


64 
16.1 


71 
17.0 


77 
17.9 


84 
18.8 


90 
19.7 


96 
20.6 


103 
21.4 


109 
22.3 


116 
23.2 


123 
24.1 


23.41 


23.49 


40 
11.6 


46 
12.5 


53 
13.4 


59 
14.3 


65 
15.2 


72 
16.1 


78 
17.0 


85 
17.9 


91 

18.8 


97 
19.7 


104 
20.6 


110 
21.4 


117 
22.3 


123 
23.2 


23.49 


23.58 


41 
10.7 


47 
11.6 


54 
12.5 


60 
13.4 


66 
14.3 


73 
15.2 


79 
16.1 


86 
17.0 


92 
17.9 


98 
18.8 


105 

19.7 


111 
20.6 


118 
21.4 


124 
22.3 


23.58 


23.66 


41 

9.8 


48 
10.7 


54 
11.6 


60 
12.5 


67 
13.4 


74 
14.3 


79 
15.2 


87 
16.1 


93 
17.0 


99 
17.9 


106 

18.8 


112 
19.7 


119 
20.6 


125 
21.4 


23.66 


23.75 


42 
8.9 


48 
9.8 


55 
10.7 


61 
11.6 


68 
12.5 


75 
13.4 


80 
14.3 


87 
15.2 


93 
16.1 


99 
17.0 


106 
17.9 


112 
18.8 


119 
19.7 


126 
20.6 


23.75 


23.83 


43 
8.0 


49 
8.9 


55 
9.8 


62 
10.7 


69 
11.6 


75 
12.5 


81 
13.4 


88 
14.3 


94 
15.2 


100 
16.1 


107 
17.0 


113 
17.9 


120 

18.8 


127 
19.7 


23.83 


23.91 


44 
7.1 


50 
8.0 


56 
8.9 


63 
9.8 


70 
10.7 


76 
11.6 


82 
12.5 


89 
13.4 


95 
14.3 


101 
15.2 


108 
16.1 


114 
17.0 


121 
17.9 


128 
18.8 


23.91 


24.00 


45 
6.3 


51 
7.1 


57 
8.0 


64 
8.9 


70 

9.8 


77 
10.7 


82 
11.6 


89 
12.5 


96 
13.4 


101 
14.3 


108 
15.2 


114 
16.1 


121 
17.0 


128 
17.9 


24.00 




12.7 


12.8 


12.9 


13.0 


13.1 


13.2 


13.3 


13.4 


13.5 


13.6 


13.7 


13.8 


13.9 


14.0 





402 



Ice Cream Mixes 



TABLE 72 (Continued). 





12.00'?e 


Fat 


Dasis 1000 rounds of 


standardizing 


9.50% 


M. S. N. F. 


mix. 


table for ice 


14.00% 


Sugar 


Top and bottom lines: 


cream mix 


.50% 


Gelatin 


Fat tests. 


No. 7 testing: 






Side columns : 




36.00% 


T. S. 


S. N. F. tests. 



In each square: 

Top figure : Pounds butter. 

Center figure: Pounds water. 

Bottom figure: Pornds skim-milk 
powder. 
(Blanks Indicate none of kind required.) 





12.7 


12.8 


12.9 


13.0 


13.1 


13.2 


13.3 


13.4 


13.5 


13.6 


13.7 


13.8 


13.9 


14 




24.08 


45 
.5.4 


52 
6.3 


58 
7.1 


65 
8.0 


71 
8.9 


77 
9.8 


83 
10.7 


90 
11.6 


97 
12.5 


103 
13.4 


109 
14.3 


115 
15.2 


122 
16.1 


129 
17.0 


24.08 


24.16 


46 

4.5 


52 
5.4 


59 
6.3 


66 
7.1 


72 
8.0 


78 
8.9 


84 
9.8 


91 
10.7 


98 
11.6 


104 
12.5 


110 
13.4 


116 
14.3 


123 
15.2 


130 
16.1 


24.16 


24.24 


47 
3.6 


53 
4.5 


59 

5.4 


67 
6.3 


73 
7.1 


79 
8.0 


85 
8.9 


91 

9.8 


99 
10.7 


105 
11.6 


111 
12.5 


117 
13.4 


123 
14.3 


131 
15.2 


24.24 


24.33 


47 

2.7 


54 
3.6 


60 
4.5 


67 
5.4 


74 
6.3 


80 

7.1 


86 
8.0 


92 

8.9 


99 

9.8 


106 
10.7 


112 
11.6 


118 
12.5 


124 
13.4 


132 
14.3 


24.33 


24.41 


48 
1.8 


54 
2.7 


61 
3.6 


68 
4.5 


74 
5.4 


81 
6.3 


87 
7.1 


93 
8.0 


100 
8.9 


106 
9.8 


113 
10.7 


119 
11.6 


124 
12.5 


133 
13.4 


24.41 


24.49 


49 
.9 


55 
1.8 


61 
2.7 


69 
3.6 


■ 75 
4.5 


81 
5.4 


88 
6.3 


94 
7.1 


101 
8.0 


107 
8.9 


113 

9.8 


120 
10.7 


125 
11.6 


133 
12.5 


24.49 


24.58 


50 


56 
.9 


62 

1.8 


69 
2.7 


76 
3.6 


82 
4.5 


88 
5.4 


95 
6.3 


102 
7.1 


108 
8.0 


114 
8.9 


120 

9.8 


126 
10.7 


134 
11.6 


24.58 


24.66 


1.2 
56 


57 


63 
.9 


70 
1.8 


76 
2.7 


83 
3.6 


89 
4.5 


95 
5.4 


103 
6.3 


109 
7.1 


115 
8.0 


121 

8.9 


127 

9.8 


134 
10.7 


24.66 


24.74 


2.6 
62 


1.2 
63 


64 


71 
.9 


77 
1.8 


83 
2.7 


90 
3.6 


96 
4.5 


103 
5.4 


110 
6.3 


116 

7.1 


122 
8.0 


128 
8.9 


135 
9.8 


24.74 


24.83 


3.7 
69 


2.5 
70 


1.2 
71 


72 


78 
.9 


84 
1.8 


90 
2.7 


97 
3.6 


104 
4.5 


110 
5.4 


117 
6.3 


123 
7.1 


129 
8.0 


135 

8.9 


24.83 


24.91 


4.9 

75 


3.7 

76 


2.5 

77 


1.2 

78 


79 


85 
.9 


91 

1.8 


97 

2.7 


105 
3.6 


111 

4.5 


117 
5.4 


124 
6.3 


130 
7.1 


136 
8.0 


24.91 


24.99 


6.2 

81 


4.9 
82 


3.7 
83 


2.5 
84 


1.2 

85 


86 


92 
.9 


98 
1.8 


105 
2.7 


112 
3.6 


118 
4.5 


124 

5.4 


131 
6.3 


136 

7.1 


24.99 


25.07 


7.4 
87 


6.2 

88 


4.9 
89 


3.7 
90 


2.5 
91 


1.2 
92 


93 


99 
.9 


106 
1.8 


112 
2.7 


119 
3.6 


125 
4.5 


131 
5.4 


137 
6.3 


25.07 


25.16 


8.6 
93 


7.4 
94 


6.2 
95 


4.9 
96 


3.7 
97 


2.5 
98 


1.2 
99 


100 


107 
.9 


113 
1.8 


119 
2.7 


126 
3.6 


132 
4.5 


138 
5.4 


25.16 


25.24 


9.9 
99 


8.6 
100 


7.4 
101 


6.2 
102 


4.9 
103 


3.7 
104 


2,5 
105 


1.2 
107 


108 


114 
.9 


120 
1.8 


126 
2.7 


133 
3.6 


139 
4.5 


25.24 


25.33 


11.1 
106 


9.9 
107 


8.6 
108 


7.4 
109 


6.2 
110 


4.9 
111 


3.7 
112 


2.5 
113 


1.2 
114 


115 


121 
.9 


127 

1.8 


133 
2.7 


140 
3.6 


25.33 


25.41 


12.3 
111 


11.1 
113 


9.9 
114 


8.6 
115 


7.4 
116 


6.2 
117 


4.9 
118 


3.7 
119 


2.5 
120 


1.2 
121 


122 


128 
.9 


134 
1.8 


140 
2.7 


25.41 


25.49 


13.5 
118 


12.3 
119 


11.1 
120 


9.9 
121 


8.6 
122 


7.4 
123 


6.2 
124 


4.9 
125 


3.7 
126 


2.5 
127 


1.2 

128 


129 


135 
.9 


141 
1.8 


25.49 


25.58 


14.8 
123 


13.5 
124 


12.3 
126 


11.1 
127 


9.9 
128 


8.6 
129 


7.4 
130 


6.2 
131 


4.9 
132 


3.7 
133 


2.5 
134 


1.2 
135 


136 


142 
.9 


25.58 


25.66 


16.0 

129 


14.8 
130 


13.5 
131 


12.3 
132 


11.1 
133 


9.9 
134 


8.6 
136 


7.4 
137 


6.2 

138 


4.9 
139 


3.7 
140 


2.5 
141 


1.2 
142 


143 


25.66 




12.7 


12.8 


12.9 


13.0 


13.1 


13.2 


13.3 


13.4 


13.5 


13.6 


13.7 


13.8 


13.9 


14.0 





Compositions of Mixes 



403 



Standardi2ing 
table for ice 
cream mix 
No. 8 testing: 



r 16.00% Fat 



7.50% M. S. N. F 
14.00% Suiiar 
.50% Gelatin 



38.00% T. S. 



TABLE 73. 

Basis 1000 pounds of 

mi.\. 
Top ana bottom lines- 

Fat tests. 
Side oolumns: 

S. N. F. tests. 



In eacli square: 
Top figure: Pounds butter, 
tenter figure: Pounds water 
liottora figure: Pounds slcim-milk 
powder. 

(Blanlcs indicate none of kind required. ) 




404 



Ice Cream Mixes 



TABLE 73 (Continued). 



standardizing 

table for Ice 
cream mix 
No. 8 testing: 



r 16.00%' Fat 
J 7.. 50% M. S. N. 
I 14.00%. Sugar 
L .50%! Gelatin 



38.00%. T. S. 



Basis 1000 ijuuiids of 

mi-v. 
Top and bottom lines : 

Fat tests. 
Side columns : 

S. N. F. tests. 



In each square: 

Top figure: Pounds butter. 

Center figure: Pounds water. 

Bottom figure: Pounds slilm-ralilc 
powder. 
(Blanics indicate none of Itind required. ) 





14.0 


14.1 


14.2 


14.3 


14.4 


14.5 14.6 


14.7 


14.8 


14 9 


15 


15.1 


15,2 


15.3 




22 05 


31.7 
2.4 


30.2 
2.3 


28.6 
2.1 


27.0 
2.0 


25.4 
1.8 


23.8 
1.7 


22.2 
1.5 


20.6 
1.4 


19.0 
1.2 


17.4 
1.1 


15.8 
.9 


14.3 

.8 


12.6 
.6 


11.1 
.5 


22 05 


22.10 


31.6 
1.8 


30.0 
1.7 


28.4 
1.5 


26.8 
1.4 


25.2 
1.2 


23.6 
1.1 


22.0 
.9 


20.4 
.8 


18.9 
.6 


17.2 
.5 


15.6 
.3 


14.1 
.2 


12.5 
.0 


11.3 
1 


22 10 


22 15 


31.5 
1.2 


29.9 
1.1 


28.3 
.9 


26.7 
.8 


25.1 
.6 


23.5 
.5 


21.9 
.3 


20.3 
.2 


18.8 
.0 


17.5 
1 


16.3 
2 


15.0 
3 


13.8 
5 


12.5 
6 


22.15 


22.20 


31.4 
.6 


29.7 
.5 


28.1 
.3 


26.5 
.2 


25.0 
.0 


23.8 
1 


22.5 
2 


21.3 
3 


20.0 
4 


18.8 
5 


17.5 
6 


16.3 

8 


15.0 
9 


13.8 
10 


22.20 


22.25 


31.3 



30.0 
1 


28.8 
2 


27.5 
3 


26.3 
4 


25.0 
5 


23.8 
6 


22.5 

7 


21.3 

8 


20.0 
9 


18.8 
10 


17.5 
11 


16.3 
13 


15.0 
14 


22 25 


22.30 


32.5 
6 


31.3 

7 


30.0 

8 


28.8 
9 


27.5 
10 


26.3 
11 


25.0 
12 


23.8 
13 


22.5 
14 


21.3 
15 


20.0 
16 


18.8 
18 


17 5 
19 


16.3 
20 


22 30 


22.35 


33.8 
10 


32.5 
11 


31.3 
12 


30.0 
13 


28.8 
14 


27.5 
15 


26.3 
16 


25.0 
17 


23.8 
18 


22.5 
19 


21.3 
20 


20.0 
21 


18.8 
22 


17.5 
23 


22.35 


22.40 


35.0 
14 


33.8 
15 


32.5 
16 


31.3 
17 


30.0 

18 


28.8 
19 


27.5 
20 


26.3 
21 


25.0 
22 


23.8 
23 


22.5 
24 


21.3 
25 


20,0 
26 


18.8 
27 


22.40 


22.45 


36.3 
18 


35.0 
19 


33.8 
20 


32.5 
21 


31.3 
22 


30.0 
23 


28.8 
24 


27.5 
25 


26.3 
26 


25.0 
27 


23.8 

28 


22.5 
29 


21.3 
30 


20.0 
31 


22 45 


22.50 


37.5 
23 


36,3 
24 


35.0 
25 


33.8 
26 


32.5 
27 


31.3 

28 


30.0 
29 


28.8 
30 


27.5 
31 


26.3 
32 


25.0 
33 


23.8 
34 


22.5 
35 


21.3 
36 


22.50 


22.55 


38.8 
27 


37.5 

28 


36.3 
29 


35.0 
30 


33.8 
31 


32.5 
32 


31.3 
33 


30.0 
34 


28.8 
35 


27.5 
36 


26.3 
37 


25.0 
38 


23.8 
39 


22.5 
40 


22.55 


22.60 


40.0 
31 


38.8 
32 


37.5 
33 


36.3 
34 


35.0 
35 


33.8 
36 


32.5 
37 


31.3 
38 


30.0 
39 


28.8 
40 


27.5 
41 


26.3 
42 


25.0 
43 


23.8 
44 


22.60 


22.65 


41.3 
36 


40.0 
37 


38.8 
38 


37.5 
39 


36.3 
40 


35.0 
41 


33.8 
42 


32.5 
43 


31.3 
44 


30.0 
45 


38.8 
46 


27.5 

47 


26.3 

48 


25.0 
49 


22 65 


22.70 


42.5 
40 


41.3 
41 


40.0 
42 


38.8 
43 


37.5 
44 


36.3 
45 


35.0 
46 


33.8 
47 


32.5 

48 


31.3 
49 


30 
50 


28.8 
51 


27.5 
52 


26.3 
53 


22.70 


22.75 


43.8 
44 


42.5 
45 


41.3 
46 


40.0 
47 


38.8 
48 


37.5 
49 


36.3 
50 


35.0 
51 


33.8 
52 


32.5 
53 


31.3 
54 


30 
55 


28.8 
56 


27.5 
57 


22.75 


22.80 


45.0 

48 


43.8 
49 


42.5 
50 


41.3 
51 


40.0 
52 


38.8 
53 


37.5 
54 


36.3 
55 


35.0 
56 


33.8 
57 


32.5 
58 


31.3 
59 


30.0 
60 


28.8 
61 


22.80 


22.85 


46.3 
53 


45.0 
54 


43.8 
55 


42.5 
56 


41.3 
57 


40.0 

58 


38.8 
59 


37.5 
60 


36.3 
61 


35.0 
62 


33.8 
63 


32.5 
64 


31.3 
65 


30.0 
66 


22.85 


22.90 


47.5 
57 


46.3 

58 


45.0 
59 


43.8 
60 


42.5 
61 


41.3 
62 


40.0 
63 


38.8 
64 


37.5 
65 


36.3 
66 


35.0 
67 


33.8 
68 


32.5 
69 


31.3 
70 


22 90 


22.95 


48.8 
61 


47.5 
62 


46.3 
63 


45.0 
64 


43.8 
65 


42.5 
66 


41.3 
67 


40.0 

68 


38.8 
69 


37.5 
70 


36.3 
71 


35.0 
72 


33.8 
73 


32.5 
74 


22 95 


23 00 


50 

65 


48.8 
66 


47.5 
67 


46.3 

68 


45 
69 


43.8 
70 


42.5 
71 


41.3 
72 


40.0 
73 


38.8 
74 


37.5 

75 


36.3 
76 


35 

77 


33.8 

78 


23 00 




14 


14 1 


14 2 


14.3 


14.4 


14.5 


14.6 


14.7 


14.8 


14.9 


15 


15.1 


15.2 


15.3 





Compositions of Mixes 405 

TABLE 73 (Continued). 

tablP inV' i .V""'" -• ^- N. P. I ^m'ix ^""" """'"'' "^ I ^''•^ach square: 

M/> Q 4„„t: '- •?"%> Lrelatin I Fat tests. ' i^eiuer ngure: Pounds wjitor 



Standardizing I ^zisO'l M*'s. N. P. I ^mlx ^""" """'"'" °f I ^" '^ich 



No. 8 testing: 



Ss.OO'-i T. S. 



Siiie columns : 
S. N. F. tests. 



T}„»v " -„= — -■ -Pounds water. 
rSr "■ ^'""'"'' ^W'^^-niilk 
'Blanks indicate none of kind required. 







13.0 12.8 


21 


05 


12.6 10.9 
12.4 12.2 ] 


21 


10 


12.4 10.7 
11.8 11.6 1 


21 


IS 


12.3 10.6 
11 2 11.0 1 




406 



Ice Cream Mixes 



TABLE 73 (Continued). 



[16.00% Fat 
Standardizing 1 7.50% M. S. N. F, 

table for ice | 14.00% Sugar 
cream mix [ .50% Gelatin 

No. 8 testing: 

3S.007(. T. S. 



Basis 1000 pounds of 

mix. 
Top and bottom Unes; 

Fat tests. 
Side columns : 

S. N. F. tests. 



In eacli square : 

Top figure : Pounds butter. 

Center figure: Pounds water. 

Bottom figure; Pounds slclm-mills 
powder. 
(Blanlcs indicate none of liind required.) 





15.4 


15 5 


15.6 


15.7 


15,8 


15 9 


16.0 


16.1 


16.2 


16.3 


16.4 


16.5 


16 6 


16 7 




22.05 


9,5 
.3 


7.9 
.2 


6,3 
.0 


5,0 
1 


3.S 
2 


2.5 
3 


1,3 
4 


5 


11 
,5 


15 
11 


20 
1,6 


25 
2 . 2 


29 
2.7 


35 
3,3 


22 05 


22 10 


10.0 
2 


8.8 
3 


7.5 
4 


6.3 
5 


5,0 


3,8 

8 


2.5 
9 


1,3 
10 


11 


16 
.5 


20 
1.1 


26 
1.6 


30 
2.2 


35 
2.7 


22 10 


22.15 


11.3 

7 


10,0 

8 


8.8 
9 


7.5 
10 


6,3 
11 


5,0 
12 


3.S 
13 


2,5 
14 


1,3 
15 


16 


21 
.5 


26 
1.1 


30 
1.6 


36 

2.2 


22.15 
22 20 


22 20 


12.5 
11 


11,3 

12 


10.0 
13 


8.8 
14 


7,5 
15 


6.3 
16 


5,0 
17 


3.8 
18 


2.5 
19 


1.3 
20 


21 


27 


31 
1.1 


36 
1.6 


22 25 


13.8 
15 


12.5 
16 


113 
17 


10.0 
19 


8,8 
20 


7.5 
21 


6.3 
22 


5.0 
23 


3.8 
24 


2.5 
25 


1.3 
26 


27 


31 

.5 


37 
1.1 


22 25 


22.30 


15.0 
21 


13.8 
22 


12.5 
23 


11.3 

24 


10,0 
25 


8.8 
26 


7.5 
27 


6.3 

28 


5.0 

29 


3.8 
29 


2.5 
30 


1.3 
31 


32 


37 
.5 


22.30 


22.35 


16.3 
24 


15.0 
25 


13.8 
26 


12.5 

27 


11.3 

28 


10.0 
29 


8.8 
30 


7.5 
31 


6.3 
32 


5.0 
33 


3.8 
34 


2.5 
35 


1.3 
36 


37 


22 35 


22.40 


17.5 
28 


16.3 

29 


15.0 
30 


13,8 
31 


12.5 
32 


11.3 
33 


10,0 
34 


8.8 
35 


7.5 
36 


6.3 
38 


5,0 
39 


3.8 
40 


2.5 
41 


1.3 
42 


22.40 


22.45 


18.8 
32 


17.5 
33 


16.3 
34 


15.0 
35 


13.8 
36 


12.5 
37 


11.3 
39 


10.0 
40 


8.8 
41 


7.5 
42 


6.3 
43 


5.0 

44 


3.8 
45 


2.5 
46 


22.45 


22.50 


20.0 
37 


18.8 
38 


17.5 
39 


16.3 
40 


15.0 
41 


13.8 
42 


12.5 

43 


11.3 
44 


10.0 
45 


8.8 
46 


7.5 

47 


6.3 

48 


5.0 

49 


3.8 
50 


22 50 


22 55 


21.3 
41 


20.0 
42 


18.8 
43 


17.5 
44 


16.3 
45 


15.0 
46 


13.8 
47 


12.5 

49 


11.3 
50 


10.0 
51 


8.8 
52 


7.5 
53 


6.3 
54 


5.0 

55 


22 55 


22 60 


22.5 
45 


21.3 

46 


20.0 
47 


18.8 
48 


17, 5 
49 


16.3 
50 


15.0 
51 


13.8 
52 


12.5 
53 


U.3 
55 


10.0 
56 


8.8 
57 


7.5 

58 


6.3 
59 


22.60 


22 65 


23.8 
50 


22.5 
51 


21,3 

52 


20,0 
53 


18.8 
54 


17.5 
55 


16.3 
56 


15.0 
57 


13.8 

58 


12.5 
59 


11.3 
60 


10.0 
61 


8.8 
62 


7,5 
63 


22 65 


22.70 


25.0 
54 


23.8 
55 


22,5 
56 


21,3 
57 


20.0 

58 


18.8 
59 


17.5 
60 


16.3 
62 


15.0 
63 


13.8 
64 


12.5 
65 


11.3 
66 


10.0 
67 


8.8 
68 


22 70 


22 75 


26.3 

58 


25.0 
59 


23,8 
60 


22,5 
61 


21.3 
62 


20.0 
63 


18.8 
64 


17.5 
65 


16.3 
67 


15.0 

68 


13.8 
69 


12.5 
70 


11.3 
71 


10.0 

72 


22,75 


22 80 


27.5 
62 


26.3 
63 


25.0 
64 


23,8 
65 


22.5 
66 


21.3 
67 


20.0 

68 


18.8 
70 


17.5 

71 


16.3 
72 


15,0 
73 


13.8 
74 


12.5 
75 


11.3 
76 


22 80 


22 85 


28.8 
67 


27.5 
68 


26.3 
69 


25,0 
70 


23.8 
71 


22.5 
72 


21.3 
73 


20.0 

74 


18.8 
75 


17.5 
76 


16,3 

77 


15.0 
79 


13.8 
80 


12.5 
81 


22 85 


22 90 


30.0 
71 


28.8 
72 


27.5 
73 


26.3 

74 


25.0 
75 


23.8 
76 


22.5 

77 


21.3 

78 


20.0 
80 


18.8 
81 


17.5 

82 


16.3 

S3 


15.0 

84 


13.8 

85 


22 90 


22 95 


31.3 
75 


30.3 

77 


28.8 
78 


27.5 
79 


26.3 
80 


25.0 
81 


23.8 
82 


22.5 
83 


21.3 

84 


20.0 
85 


18.8 
86 


17.5 
87 


16.3 

88 


15.0 
89 


22 95 


23 00 


32.5 

79 


31.3 
80 


30,0 

82 


28.8 
83 


27,5 

84 


26.3 

85 


25.0 

80 


23.8 

87 


22,5 

88 


21.3 

89 


20 

90 


18,8 
92 


17.5 
93 


16.3 
94 


23 00 




15.4 


15.5 


15.6 


15 7 


15 8 


15 9 


16 


16,1 


16.2 


16.3 


16,4 


16 5 


16.6 


16 7 





Compositions of Mixes 



407 



TABLE 73 (Continued), 



standardizing 
table for ice 
cream mix 
No. 8 testing: 



16.00% Fat 

7.50% M. S. N. F. 
14.00% Susar 
.50% Gelatin 



38.00% T. S. 



Basis 1000 pounds of 

mix. 
Top and bottom lines : 

Fat tests. 
Side columns: 

S. N. F. tests. 



In eacii square : 

Top figure : Pounds butter. 

Center tigure: Pounds water. 

Bottom figure: Pounds skim-milk 
powder. 
(Blanks indicate none of kind required.) 



' 


16.8 


16 9 


17.0 


17.1 


17.2 


17.3 


17.4 


17.5 


17.6 


17.7 


17.8 


17.9 


18.0 




21 00 


29 
15.2 


34 

15.8 


39 
16.3 


43 
16.8 


48 
17.4 


53 
17.9 


58 
18.5 


63 
19.0 


68 
19.5 


72 
20.1 


77 
20.6 


82 
21.2 


87 
21.7 


21.00 


21 05 


29 

14.7 


34 

15.2 


39 
15.8 


43 
16.3 


48 
16.8 


54 
17.4 


58 
17.9 


63 
18.5 


69 
19.0 


72 
19.5 


77 
20.1 


82 
20.6 


87 
21.2 


21 .05 


21.10 


30 
14.1 


35 
14.7 


40 
15.2 


44 
15.8 


49 
16.3 


54 

16.8 


59 
17.4 


64 
17.9 


69 
18.5 


73 
19.0 


78 
19.5 


83 
20.1 


88 
20.6 


21 .10 


21 15 


30 
13.6 


35 
14.1 


40 
14.7 


44 
15.2 


49 
15.8 


55 
16.3 


59 
16.8 


64 
17.4 


70 
17.9 


73 
18.5 


78 
19.0 


83 
19.5 


88 
20.1 


21.15 


21 .20 


31 
13.0 


36 
13.6 


41 
14.1 


45 
14.7 


50 
15.2 


55 
15.8 


60 
16.3 


65 
16.8 


70 
17.4 


74 
17.9 


79 
18.5 


84 
19.0 


89 
19.5 


21.20 


21.25 


31 
12.5 


36 
13.0 


4) 
13.6 


45 
14.1 


50 
14.7 


56 
15.2 


60 
15.8 


65 
16.3 


71 
16.8 


74 
17.4 


79 
17.9 


84 
18.5 


89 
19.0 


21 .25 


21.30 


32 
11.9 


37 
12.5 


42 
13.0 


46 
13.6 


51 
14.1 


56 
14.7 


61 
15.2 


66 
15.8 


71 
16.3 


75 
16.8 


80 
17.4 


85 
17.9 


90 
18.5 


21.30 


21.35 


32 
U.4 


37 
11.9 


42 
12.5 


46 
13.0 


51 
13.6 


57 
14.1 


61 

14.7 


66 
15.2 


72 
15.8 


75 
16.3 


80 

16.8 


85 
17.4 


90 

17.9 


21 .35 


21 .40 


33 
10.9 


38 
11.4 


43 
11.9 


47 
12.5 


52 
13.0 


57 
13.6 


62 
14.1 


67 
14.7 


72 
15.2 


76 
15.8 


81 
16,3 


86 
16.8 


91 

17.4 


21.40 


1 .45 
21.50 


33 
10.3 


38 
10.9 


43 
11.4 


47 
11.9 


52 
12.5 


58 
13.0 


62 
13.6 


67 
14.1 


73 
14.7 


76 
15.2 


81 
15.8 


86 
16.3 


91 
16.8 


21.45 


34 

9.8 


39 
10.3 


44 
10.9 


48 
11.4 


53 
11.9 


58 
12.5 


63 
13.0 


68 
13.6 


73 
14.1 


77 
14.7 


82 
15.2 


87 
15.8 


92 
16.3 


21.50 


21 55 


34 
9.2 


39 

9.8 


44 
10.3 


48 
10.9 


53 
11.4 


59 
11.9 


63 
12.5 


68 
13.0 


74 
13.6 


77 
14.1 


82 
14.7 


87 
15.2 


92 
15.8 


21.55 


21.60 


35 

8.7 


40 
9.2 


45 
9.8 


49 
10.3 


54 
10,9 


59 
11.4 


64 
11.9 


69 
12.5 


74 
13.0 


78 
13.6 


83 
14.1 


88 
14.7 


93 
15.2 


21.60 


21.65 


35 

8.1 


40 

8.7 


45 
9.2 


49 
9.8 


54 
10.3 


60 
10.9 


64 
11.4 


69 
11.9 


75 
12.5 


78 
13.0 


83 
13.6 


88 
14.1 


93 

14.7 


21 .65 


21.70 


36 
7.6 


41 
8.1 


46 

8.7 


50 
9.2 


55 
9.8 


00 
10.3 


65 
10.9 


70 
11.4 


75 
11.9 


79 
12.5 


84 
13.0 


89 
13.6 


94 
14.1 


21.70 


21.75 


36 
7.1 


41 

7.6 


46 
8.1 


50 

8.7 


55 
9.2 


61 
9.8 


65 
10.3 


70 
10.9 


76 
11.4 


79 
11.9 


84 
12.5 


89 
13.0 


94 
13.6 


21.75 


21 80 


37 
6.5 


42 
7.1 


47 
7.6 


51 
8.1 


56 

8.7 


61 
9.2 


66 
9.8 


71 
10.3 


76 
10.9 


80 
11.4 


85 
11.9 


90 

12.5 


95 
13.0 


21 .80 


21.85 


37 
6.0 


42 
6.5 


47 
7.1 


51 
7.6 


56 

8.1 


62 

8.7 


66 
9.2 


71 
9.8 


77 
10.3 


80 
10.9 


85 
11 .4 


90 
11.9 


95 
12.5 


21.85 


21 90 


38 
5.4 


43 
6.0 


48 
6.5 


52 

7.1 


57 
7.6 


62 
8.1 


67 

8.7 


72 
9.2 


77 
9.8 


81 
10.3 


86 
10.9 


91 
11.4 


96 
11.9 


21.90 


21.95 


38 

4.9 


43 
5.4 


48 
6.0 


52 
6.5 


57 
7.1 


63 
7.6 


67 
8.1 


72 
8.7 


78 
9.2 


81 
9.8 


86 
10.3 


91 
10.9 


96 
U.4 


21.95 


22.00 


39 
4.3 


44 

4.9 


49 
5.4 


53 
6.0 


58 
6 5 


63 
7.1 


68 
7.6 


73 
8.1 


78 
8.7 


82 
9.2 


87 
9.8 


92 
10.3 


97 
10.9 


22.00 




16.8 


16.9 


17.0 


17.1 


17.2 


17.3 


17.4 


17.5 


17.6 


17.7 


17.8 


17.9 


18.0 





408 



Ice Cream Mixes 



standardizing 
table for ice 
nream mix 
No. 8 testing: 



TABLE 73 (Continued). 




Basis 1000 pounds of 

mix. 
Top and bottom lines : 

Fat tests. 
Side columns : 

S. N. F. tests. 



Ill eacli square: 

Top figure : Pounds butter. 

Center flgure: Pounds water. 

Bottom figure: Pounds skim -milk 
powder. 
(Blanks indicate none of kind required.) 





16.8 


16 9 


17.0 


17.1 


17 2 


17.3 


17.4 


17.5 


17 6 


17.7 


17.8 


17.9 


18.0 




22.05 


39 
3.8 


44 
4.3 


49 
4.9 


53 
5.4 


58 
6.0 


64 
6.5 


68 
7.1 


73 
7.6 


79 
8.1 


82 
8.7 


87 
9.2 


92 
9.8 


97 
10.3 


22.05 


22.10 


40 
3.3 


45 
3.8 


50 
4.3 


54 
4.9 


59 
5.4 


64 
6.0 


69 
6.5 


74 
7.1 


79 
7.6 


83 
8.1 


88 
8.7 


93 
9.2 


98 
9.8 


22.10 


22.15 


40 

2.7 


45 
3.3 


50 
3.8 


54 
4.3 


59 
4.9 


65 
5.4 


69 
6.0 


74 
6.5 


80 
7.1 


83 
7.6 


88 
8.1 


93 

8.7 


99 
9.2 


22.15 


22 20 


41 
2.2 


46 

2.7 


51 
3.3 


55 
3.8 


60 
4.3 


65 
4.9 


70 
5.4 


75 
6.0 


80 
6.5 


84 
7.1 


89 
7.6 


94 

8.1 


99 

8.7 


22 20 


22 25 


41 
1.6 


46 
2.2 


51 
2.7 


55 
3.3 


60 
3.8 


66 
4.3 


70 
4.9 


75 
5.4 


81 
6.0 


84 
6.5 


89 
7.1 


94 
7.6 


100 
8.1 


22.25 


22.30 


42 
1.1 


47 
1.6 


52 
2.2 


56 
2.7 


61 
3.3 


66 
3.8 


71 
4.3 


76 
4.9 


81 
5.4 


85 
6.0 


90 
6.5 


95 
7.1 


100 
7.6 


22.30 


22.35 


42 
.5 


47 
1.1 


52 
1.6 


56 
2.2 


61 
2.7 


67 
3.3 


71 

3.8 


76 
4.3 


82 
4.9 


85 
5.4 


90 
6.0 


95 
6.5 


101 
7.1 


22.35 


22.40 


43 


48 
.5 


53 
1.1 


57 
1.6 


62 
2.2 


67 

2.7 


72 
3.3 


77 
3.8 


82 
4.3 


86 
4.9 


91 

5.4 


96 
6.0 


101 
6.5 


22.40 


22.45 


1.3 

47 


48 


S3 
.5 


57 
1.1 


62 
1.6 


68 
2.2 


72 
2.7 


77 
3.3 


83 
3.8 


86 
4.3 


91 

4.9 


96 
5.4 


102 
6.0 


22.45 


22 50 


2.5 
51 


1.3 
52 


53 


58 
.5 


63 
1.1 


68 
1.6 


73 
2.2 


78 
2.7 


83 
3.3 


87 
3.8 


92 
4.3 


97 
4.9 


102 
5.4 


22.50 


22.55 


3.8 
56 


2.5 
57 


1.3 
58 


59 


63 
.5 


69 
1 1 


73 
1.6 


78 
2.2 


84 
2.7 


87 
3.3 


92 
3.8 


97 
4.3 


103 

4.9 


22.55 


22.60 


5.0 
60 


3.8 
61 


2.5 
62 


1.3 
63 


64 


69 
.5 


74 
1.1 


79 
1.6 


84 
2.2 


88 
2.7 


93 
3.3 


98 
3.8 


103 
4.3 


22 60 


22.65 


6.3 

64 


5.0 
65 


3.8 
66 


2.5 
67 


1.3 

68 


69 


74 
.5 


79 
1.1 


85 
1.6 


88 
2.2 


93 

2.7 


98 
3.3 


104 
3.8 


22.65 


22.70 


7.5 
69 


6.3 
70 


5.0 
71 


3.8 
72 


2.5 
73 


1.3 

74 


75 


80 
.6 


86 
1.1 


89 
1.6 


94 
2.2 


99 
2.7 


104 
3.3 


22.70 


22.75 


8.8 
73 


7.5 
74 


6.3 

75 


5.0 
76 


3.8 

77 


2.5 

78 


1.3 

79 


80 


85 
.5 


89 
1.1 


94 
1.6 


99 
2.2 


105 
2.7 


22.75 


22.80 


10.0 

77 


8.8 
78 


7.5 
79 


6.3 
80 


5.0 

81 


3.8 
82 


2.6 
83 


1.3 

84 


85 


90 
.5 


96 
1.1 


100 
1.6 


106 
2.2 


22 80 


22.85 


11.3 
82 


10.0 
83 


8.8 
84 


7.5 
85 


6.3 

86 


5.0 

87 


3.8 
88 


2.5 
89 


1.3 
90 


91 


95 
.6 


101 
1.1 


106 
1.6 


22.85 


22.90 


12.5 
86 


11.3 

87 


10.0 

88 


8.8 
89 


7.5 
90 


6.3 
91 


5.0 
92 


3.8 
93 


2.5 

94 


1.3 
95 


96 


101 
.6 


106 
1.1 


22 90 


22 95 


13.8 
90 


12.5 
92 


11.3 
93 


10.0 
94 


8.8 
95 


7.5 
96 


6.3 
97 


5.0 

98 


3.8 
99 


2.5 
100 


1.3 
101 


102 


107 
.5 


22.95 


23.00 


15.0 
95 


13.8 
96 


12.5 
97 


11.3 

98 


10.0 
99 


8.8 
100 


7.6 
101 


6.3 
102 


5.0 
103 


3.8 
104 


2.5 
105 


1.3 
106 


107 


23.00 




16.8 


16.9 


17.0 


17.1 


17.2 


17.3 


17.4 


17.5 


17.6 


17.7 


17.8 


17.9 


18.0 





Compositions of Mixes- 

TABLE 74. 



409 



standardizing 
table for ice 
cream mix 
No. 9 testing: 



flS.00% Fat 

' 7.50% W. S. N. F. 



1 14.'u0% Sugar 
L .50% - 



Gelatin 



40.00'; T. s. 



Basis 1000 jiounds of 

mi.\. 
Top and bottom lines ■ 

Fat tests. 
.Side colmnns: 

t^- X F. tests. 



In each square : 

Top figure: Pounds Ijutter. 

Center figure: Pounds water, 
powder -"• ■^"""'^' sklm-mllk 
(Blanlis indicate none of Itind required, i 




410 



Ice Cream Mixes 



standardizing 
table for ice 
cream mix 
No. 9 testing: 



TABLE 74 (Continued). 



r 18.00% Pat 

I 7.50% M. S. N. P. 

1 14.00% Susar 

L .50% Gelatin 

40.00% T. S. 



Basis 1000 pounds of 

mix. 
Top and bottom lines: 

Pat tests. 
Side columns : 

S. N. P. tests. 



In each square : 

Top figure: Pounds butter. 

Center figure: Pounds water. 

Bottom figure: Pounds skim-milk 
oowder. 
(Blanks indicate none of kind required.) 





16.0 


16 1 


16 2 


16.3 


16.4 


16.5 


16 6 


16.7 


16.8 


16.9 


17.0 


17.1 


17.2 


17.3 




22.04 


33.6 

2.7 


i2.0 
2.5 


30.2 
2.4 


28.5 
2.3 


26.8 
2.1 


25.2 
2.0 


23.5 
1.8 


21.8 
1.6 


20.1 
1.4 


18.4 
1.3 


16.7 
1.1 


15.0 
1.0 


13.3 
.8 


11.6 
.6 


22.04 


22.09 


33.4 
2.2 

33.3 
1.7 


31.8 
2.0 


30.1 
1.9 


28.3 
1.7 


26.6 
1.6 


25.0 
1.4 


23.4 
1.2 


21.7 
1.1 


19.9 
.9 


18.2 

.8 


16.5 
.6 


14.8 
.5 


13.1 
.3 


U.3 

1 


22 09 


23.13 


31.6 
1.5 


29.9 
1.4 


28.2 
1.2 


26.4 
1.1 


24.9 
.9 


23.2 
.7 


21.5 
.6 


19.4 
.4 


18.0 
.2 


16.3 
1 


15.1 
2 


13.8 
3 


12.5 
4 


22.13 


22.18 


33.1 
1.2 


31.4 
1.0 


29.7 
.9 


28.0 

.7 


26.3 
.6 


24.8 

.4 


22.6 
1 


21.3 
2 


20.1 
3 


18.8 
4 


17.6 
5 


16.3 
6 


15.1 

7 


13.8 

8 


22.18 


22.22 


32.9 
.6 


31.2 
.4 


28.4 

1 


27.6 
2 


26.4 
3 


25.1 
4 


23.8 
5 


22.6 
6 


21.3 

7 


20.1 

8 


18.8 
9 


17.6 
10 


16.3 
11 


15.1 
12 


22.22 


22.26 


32.6 
3 


31.4 
4 


30.1 
5 


28.9 
6 


27.6 

7 


26.4 

8 


25.1 
9 


23.8 
10 


22.6 
11 


21.3 
12 


20.1 
13 


18.8 
14 


17.6 
15 


16.3 
16 


22.26 


22.31 


33.9 

7 


32.6 

8 


31.4 
9 


30.1 
10 


28.9 
11 


27.6 
12 


26.4 
13 


25.1 
14 


23.8 
15 


22.6 
16 


21.3 
17 


20.1 

18 


18.8 
19 


17.6 
20 


22 31 


22.36 


35.1 
10 


33.9 
11 


32.6 
12 


31.4 
13 


30.1 
14 


28.9 
15 


27.6 
16 


26.4 
17 


25.1 
18 


23.8 
19 


22.6 
20 


21.3 
21 


20.1 
22 


18.8 
23 


22.36 


22.40 


36.4 
14 


35.1 
15 


33.9 
16 


32.6 
17 


31.4 
18 


30.1 
19 


28.9 
20 


27.6 
21 


26.4 
22 


25.1 
23 


23.8 
24 


22.6 
25 


21.3 
26 


20.1 

27 


22.40 


22.44 


37.6 
17 


36.4 
18 


35.1 
19 


33.9 
20 


32.6 
21 


31.4 
22 


30.1 
23 


28.9 
24 


27.6 
25 


26.4 
26 


25.1 
27 


23.8 
28 


22.6 
30 


21.3 
31 


22.44 


22 49 


38.9 
21 


37.6 
22 


36.4 
23 


35.1 

24 


33.9 
25 


32.6 
26 


31.4 
27 


30.1 

28 


28.9 
29 


27.6 
30 


26.4 
31 


25.1 
32 


23.8 
33 


22.6 
34 


22.49 


22.53 


40.2 
24 


38.9 
25 


37.6 
26 


36.4 
27 


35.1 

28 


33.9 
29 


32.6 
30 


31.4 
31 


30.1 
32 


28.9 
33 


27.6 
34 


26.4 
35 


25.1 
36 


23.8 
37 


22.53 


22 58 


41.4 
28 


40.2 
29 


38.9 
30 


37.6 
31 


36.4 
32 


35.1 
33 


33.9 
34 


32.6 
35 


31.4 
36 


30.1 
37 


28.9 
38 


27.6 
39 


26.4 
40 


25.1 
41 


22.58 


22 62 


42.7 
32 


41 .'4 
33 


40.2 
34 


38.9 
35 


37.6 
36 


36.4 
37 


35.1 
38 


33.9 
39 


32.6 
40 


31.4 
41 


30.1 
42 


28.9 
43 


27.6 
44 


26.4 
46 


22.62 


22.67 


43.9 
36 


42.7 
37 


41.4 
38 


40.2 
39 


38.9 
40 


37.6 
41 


36.4 
42 


35.1 
43 


33.9 
44 


32.6 
45 


31.4 
46 


30.1 

47 


28.9 
48 


27.6 
49 


22.67 


22.71 


45.2 
39 


43.9 
40 


42.7 
41 


41.4 

42 


40.2 
43 


38.4 
, 44 


37.6 
45 


36.4 
46 


35.1 

47 


33.9 

48 


32.6 
49 


31.4 
50 


30.1 

5i 


28.9 
52 


22.71 


22.76 


46.4 
43 


45.2 

44 


43.9 
45 


42.7 
46 


41.4 

47 


40.2 

48 


38.9 
49 


37.6 
50 


36.4 
51 


35.1 
52 


33.9 
53 


32.6 
54 


31.4 
55 


30.1 
56 


22.76 


22.80 


47.7 
47 


46.4 

48 


45 2 

49 


43. f 
50 


42.7 
51 


41.4 
52 


40.2 
53 


38.9 
54 


37.6 
55 


36.4 
56 


35.1 
57 


33.9 
58 


32.6 
59 


31.4 
60 


22.80 


22.85 


48. S 
51 


47.7 
52 


46.4 

53 


45.2 
54 


43.9 
55 


42.7 
5€ 


41.4 
57 


40.2 
5S 


38.(1 
59 


37. f 

60 


36.4 
61 


35.1 
62 


33.9 
63 


32.6 
64 


22.85 


22.89 


50.2 

5-1 


48. f 
5t 


47.7 
5C 


46.4 

5' 


45.2 


43. £ 
5£ 


42.7 
6C 


41.4 
61 


40.2 
62 


38. t 
6C 


37. e 
64 


36.4 

6: 


35.1 

66 


33.9 
67 

17.3 


22 89 




16. ( 


) 16.1 


16.2 


16.: 


16. 4 


16. J 


16 « 


16.- 


16. f 


16. J 


17. t 


17.1 


17.2 



Compositions of Mixes 



411 



TABLE 74 (Continued). 



standardizing 
table for ice 
cream mix 
No. 9 testing: 



r 18.00% Fat 
J 7.50% M. S. N. 
1 14,00% Sugar 
L .50% Gelatin 



40.007c T. S. 



Basis 1000 rounds of 

mix. 
Top and bottom lines: 

Fat tests. 
Side columns: 

S. N. F. tests. 



In each square: 

Top figure : Pounds butter. 

Center figure: Pounds water. 

Bottom figure: Pounds skira-milk 
powder. 
(Blanlts indicate none of kind required.) 





17.4 


17.5 


17.6 


17 7 


17.8 


17 9 


18.0 


18.1 


18.2 


18.3 


18.4 


18,5 


18.6 


18.7 




21.11 


13.4 
11.8 


11.7 
11.6 


10.0 
11.5 


8.4 
11.3 


6.7 
11.2 


5.0 
11.0 


3.3 
10.9 


1.6 
10.7 


.0 
10.4 


4 
10.9 


9 
11.4 


13 
11.8 


17 
12.3 


22 
12.8 


21.11 


21.16 


13.2 
11.2 


11.5 
11.0 


9.8 
10.9 


8.2 
10.7 


6.5 
10.6 


4.8 
10.4 


3.1 
10.3 


1.4 
10.1 


1 
9.9 


4 
10.4 


9 
10.9 


13 
11.4 


17 

11.8 


22 
12.3 


21 .16 


21 20 


13.0 
10.5 


11.3 
10.4 


9.6 
10.3 


8.0 
10.2 


6.3 
10.1 


4.6 
10.0 


2.9 
9.8 


1.2 
9.6 


1 
9.5 


5 
9.9 


10 
10.4 


14 
10.9 


18 
11.4 


23 
11.8 


21 20 


21 .24 


12.9 
10.2 


11.2 
10. 1 


9.5 
9.9 


7.9 
9.7 


6.2 
9.6 


4.5 
9.4 


2.8 
9.3 


1.1 
9.1 


2 
9.0 


5 
9.5 


10 
9.9 


14 
10.4 


18 
10.9 


23 
11.4 


21.24 


21.29 


12.7 
9.6 


11.0 
9.4 


9.3 
9.3 


7.7 
9.1 


6.0 
9.0 


4.3 
8.9 


2.6 

8.7 


.9 

8.5 


2 
8.5 


6 
9.0 


11 
9.5 


15 
9.9 


18 
10.4 


24 
10.9 


21.29 


21.33 


12.6 
9.1 


10.9 
8.9 


9.2 

8.8 


7.6 

8.7 


5.9 
8.5 


4.2 
8.3 


2.5 
8.2 


.8 
8.0 


3 

8.0 


6 
8.5 


11 
9.0 


15 
9.5 


19 
9.9 


24 
10.4 


21.33 


21.38 


12.4 

8.7 


10.7 
8.6 


9.0 

8.4 


7.4 

8.2 


5.7 
8.0 


4.0 

7.8 


2.3 
7.6 


.6 
7.4 


3 
7.6 


7 
8.0 


12 

8.5 


15 
9.0 


19 
9.5 


24 
9.9 


21 38 


21 .42 


12.3 
8.0 


10. 6 

7.9 


8.9 

7.7 


7.3 
7.6 


5.6 

7.4 


3.8 
7.3 


2.1 
7.1 


.4 
7.0 


4 
7.1 


7 
7.6 


12 
8.0 


16 
8.5 


20 
9.0 


25 
9.5 


21.42 


21.47 


12.1 

7.4 


10.4 

7.2 


8.7 
7.1 


7.1 
6.8 


5.4 
6.7 


3.7 
6.6 


2.0 
6.5 


.3 

6.3 


4 
6.7 


8 
7.1 


12 

7.6 


16 
8.0 


20 

8.5 


25 
9.0 


21.47 


21.51 


11.9 
7.0 


10.2 
6.8 


8.5 
6.7 


6.9 
6.5 


5.2 
6.4 


3.5 
6.2 


1.8 
6.0 


.1 
5.8 


5 
6.2 


8 
6.7 


13 
7.1 


17 
7.6 


21 
8.0 


26 

8.5 


21.51 


21.56 


11.8 
6.2 


10.1 
6.0 


8.4 
5.9 


6.8 
5.7 


5.1 
5.6 


3.4 
5.5 


1.7 
5.4 



5.2 


5 
5.7 


9 
6.2 


13 
6.7 


17 

7.1 


21 

7.6 


26 
8.0 


21.56 


21.60 


11.6 
5.9 


9.9 
5.7 


8.2 
5.6 


6.6 
5.4 


4.9 
5.2 


3.2 
5.0 


1.5 
4.9 


1 
4.7 


6 
5.2 


9 
5.7 


14 
6.2 


17 
6.7 


21 
7.1 


26 
7.6 


21.60 


21.64 


11.5 
5.3 


9.8 
5.1 


8.1 
5.0 


6.5 
4.8 


4.8 
4.6 


3.0 
4.5 


1.3 
4.3 


1 

4.2 


6 

4.7 


9 
5.2 


14 
5.7 


18 
6.2 


22 
6.7 


27 
7.1 


21 .64 


21.69 


11.3 
4.6 


9.6 

4.5 


7.9 
4.4 


6.3 
4.3 


4.6 
4.2 


2.9 
4.0 


1.2 
3.8 


2 
3.8 


6 
4.2 


10 

4.7 


15 
5.2 


18 
5.7 


22 
6.2 


27 
6.7 


21.69 


21.73 


11.1 
4.2 


9.4 
4.0 


7.7 
3.9 


6.1 
3.7 


4.4 
3.6 


2.7 
3.4 


1.0 
3.3 


2 
3.3 


7 
3.8 


10 

4.2 


15 

4.7 


19 
5.2 


23 
5.7 


28 
6.2 


21.73 


21.78 


11.0 
3.6 


9.3 
3.5 


7.6 
3.3 


6.0 
3.1 


4.3 
3.0 


2.5 
2.9 


.8 
2.7 


3 

2.8 


7 
3.3 


11 

3.8 


15 
4.2 


19 
4.7 


23 
5.2 


28 
5.7 


21.78 


21.82 


10.8 
3.1 


9.1 
2.9 


7.4 
2.8 


5.8 
2.6 


4.1 
2.5 


2.4 

2.4 


.7 
2.2 


3 
2.4 


8 
2.8 


11 
3.3 


16 
3.8 


19 
4.2 


23 
4.7 


28 
5.2 


21.82 


21 87 


10.6 
2.5 


8.9 
2.3 


7.2 
2.1 


5.6 
2.0 


3.9 
1.9 


2.2 
1.8 


.5 
1.6 


4 
1,9 


8 
2.4 


11 

2.8 


16 
3.3 


20 

3.8 


24 

4.2 


29 
4.7 


21.87 


21 91 


10.5 
2.1 


8.8 
1.9 


7.1 
1.7 


5.5 
1.6 


3.8 
1.4 


2.0 
1.3 


.3 
1.1 


4 
1.4 


9 
1.9 


12 
2.4 


17 

2.8 


20 
3.3 


24 
3.8 


29 
4.2 


21 .91 


21 .96 


10.4 
l.S 


8.6 
1.3 


7.0 
1.1 


5.3 
1.0 


3.6 

.8 


1.9 

.7 


.2 
.5 


4 
.9 


9 
1.4 


12 

1.9 


17 
2.4 


21 

2.8 


25 
3.3 


30 
3.8 


21.96 


22.00 


10 2 
10 


8.4 
.8 


6.8 
.6 


5.1 
.5 


3.4 
.3 


1.7 
.2 




5 
.5 


9 
.9 


13 
1.4 


17 
1.9 


21 

2.4 


25 

2.8 


30 
3.3 


22.00 




17 4 


17.5 


17.6 


17.7 


17.8 


17.9 


18.0 


18.1 


18.2 


18.3 


18.4 


18 5 


18.6 


18.7 





412 



Ice: Cre:am Mixes 



TABLE 74 (Continued). 



r IS.OO^r Fat 
Standardizing J 7.50% M. S. N. F. 
table for ice I 14.00% Sugar 
L .50% Gelatin 



40.00% T. S. 



Kasis 1000 pounds of 
mix. 

Top and bottom lines: 

Fat tests. 
Side columns: 

S. N. V. tests. 



In each square : 

Top figure: Pounds butter. 

Center figure: Pounds water. 

Bottom figure: Pounds sklm-mllk 
powder. 
(Blanks indicate none of kind required.) 





17.4 


17 5 


17 6 


17.7 


17.8 


17 9 


18.0 


18.1 


18.2 


18.3 


18.4 


18.5 


18 6 


18.7 




22 04 


10.0 
.5 


8.2 
.3 


6.6 
.1 


5.0 
1 


3.8 
2 


2.5 
3 


1.3 
4 


5 


10 

. 5 


13 
.9 


18 
1.4 


22 
1.9 


26 
2.4 


31 

2.8 


22 04 


22.09 


10.0 
2 


8.8 
3 


7.5 

4 


6.3 
5 


5.0 
6 


3.8 

7 


2.5 

8 


1.3 

9 


10 


14 
.6 


18 
.9 


22 
1.4 


26 
1.9 


31 

2.4 


22.09 


22.13 


11.3 
5 


10.0 
6 


8.8 

7 


7.5 
8 


6.3 
9 


6.0 
10 


3.8 
11 


2.5 
12 


1.3 
13 


14 


19 
.5 


23 
.9 


27 
1.4 


32 
1.9 


22 13 


22.18 
22.22 


12.5 
9 


11.3 
10 


10.0 
11 


8.8 
12 


7.5 
13 


6.3 
14 


6.0 
15 


3.8 
16 


2.6 

17 


1.3 
18 


19 


24 
.6 


28 
.9 


33 
1.4 


22 18 


13.8 
13 


12.5 
14 


11.3 
15 


10.0 
16 


8.8 
17 


7.6 
18 


6.3 
19 


5.0 
20 


3,8 
21 


2.6 
22 


1.3 
23 


24 


28 
.5 


33 
.9 


22.22 


22.26 


15.1 
17 


13.8 
18 


12.5 
19 


11.3 
20 


10.0 
21 


8.8 
22 


7.5 
23 


6.3 
24 


5.0 
26 


3.8 
26 


2.5 
27 


1.3 

28 


29 


34 
.5 


22.26 


22.31 


16.3 
21 


15.1 
22 


13.8 
23 


12.5 
24 


11.3 
25 


10.0 
26 


8.8 
27 


7.5 

28 


6.3 
29 


5.0 
30 


3.8 
31 


2.5 
32 


1.3 
33 


34 


22.31 


22.36 


17.6 

24 


16.3 
25 


15.1 
26 


13.8 
27 


12.5 

28 


11.3 
29 


10.0 
30 


8.8 
31 


7.5 
32 


6.3 
33 


5.0 
34 


3.8 
36 


2.5 
36 


1.3 
37 


22.36 


22.40 


18.8 
28 


17.6 
29 


16.3 
30 


15.1 
31 


13.8 
32 


12.5 
33 


11.3 
34 


10.0 
36 


8.8 
37 


7.5 
38 


6.3 
39 


5.0 

40 


3.8 
41 


2.6 
42 


22.40 


22.44 


20.1 
32 


18.8 
33 


17.6 
34 


16.3 
35 


15.1 
36 


13.8 
37 


12.5 
38 


11.3 
39 


10.0 
40 


8.8 
41 


7.6 
42 


6.3 
43 


5.0 

44 


3.8 
45 


22.44 


22 49 


21.3 
35 


20.1 
36 


18.8 
37 


17.6 
38 


16.3 
39 


15.1 
40 


13.8 
41 


12.5 
42 


11.3 
43 


10.0 
44 


8.8 
45 


7.5 
46 


6.3 

47 


6.0 

48 


22.49 


22.53 


22.6 
39 


21.3 
40 


20.1 
41 


18.8 
42 


17.6 
43 


16.3 
44 


15.1 
45 


13.8 
46 


12.5 
47 


11.3 

48 


10.0 
49 


8.8 
50 


7.5 
51 


6.3 
52 


22.53 


22.58 
22.62 


23.8 
42 


22.6 
43 


21.3 
44 


20.1 
45 


18.8 
46 


17.6 

47 


16.3 

48 


15.1 
49 


13.8 
51 


12.6 
62 


11.3 
53 


10.0 

54 


8.8 
55 


7.5 
56 


22.58 


25.1 

47 


23.8 
48 


22.6 
49 


21.3 
50 


20.1 
51 


18.8 
62 


17.6 
53 


16.3 
54 


15.1 
66 


13.8 
56 


12.5 
57 


11.3 

58 


10.0 
59 


8.8 
60 


22.62 


22 67 


26.4 
50 


25.1 
51 


23.8 
52 


22.6 
53 


21.3 
54 


20.1 
55 


18.8 
66 


17.6 
57 


16.3 

68 


15.1 
60 


13.8 
61 


12.5 
62 


11.3 
63 


10.0 
64 


22.67 


22.71 


27.6 
53 


26.4 
54 


25.1 
55 


23.8 
56 


22.6 
60 


21.3 
61 


20.1 
62 


18.8 
63 


17.6 
64 


16.3 
65 


15.1 
66 


13.8 
67 


12.5 
68 


11.3 
69 


22 71 


22.76 


28.9 
57 


27.6 
58 


26.4 
59 


25.1 
60 


23.8 
61 


22.6 
63 


21.3 
64 


20.1 
65 


18.8 
66 


17.6 
67 


16.3 
68 


15.1 
69 


13.8 
70 


12.5 
71 


22.76 


22.80 


30.1 
61 


28.9 
62 


27.6 
63 


26.4 
64 


25.1 
65 


23.8 
66 


22.6 
67 


21.3 
68 


20.1 
70 


18.8 
71 


17.6 
72 


16.3 
73 


15.1 
74 


13.8 
75 


22.80 


22.85 


31.4 
65 


30.1 
66 


28.9 
67 


27.6 
68 


26.4 
70 


25.1 
71 


23.8 
72 


22.6 
73 


21.3 
74 


20.1 

75 


18.8 
76 


17.6 

77 


16.3 

78 


15.1 

79 


22.85 


22 89 


32.6 
68 


31.4 
69 


30.1 
70 


28.9 
71 


27.6 
72 


26.4 
73 


25.1 
74 


23.8 
76 


22.6 
76 


21.3 

77 


20.1 

78 


18.8 
79 


17.6 
80 


16.3 
81 


22.89 




17.4 


17.5 


17.6 


17.7 


17.8 


17.9 


ISO 


18.1 


18.2 


18.3 


18.4 


18.5 


18.6 


18.7 





Compositions o^ Mixes 



413 



TABLE 74 (Continued). 



StanDardi^ing 
Standardizing 
cream mix 
No. 9 testing: 



f IS-OOVf Fat 

J 7.50% M. S. N. F. 

1 I'l.OO^^; Sugar 

I .50% Gelatin 



40.00 7r T. S. 



Basis 1000 pounds of 

mix. 
Top and bottom lines : 

Fat tests. 
Side columns: 

S. N. F. tests. 



In eacii snuare: 

Toi) figure : Pounds butter. 

Center figure: Pounds water. 

Bottom figure: Pounds skim-mllk 
powder. 
(Blanks indicate none of kind required.) 





18 8 


18 9 


19 


19 1 


19.2 


19 3 


19.4 


19.5 


19.6 


19 7 


19 8 


19.9 


20.0 




21.11 


26 
13.2 


30 
13.8 


35 
14.2 


39 
14.7 


43 
15.1 


47 
15.6 


52 
16.1 


56 
16.5 


61 
17.0 


65 
17.5 


69 
17.9 


74 

18.4 


78.0 
18.9 


21,11 


21.16 


26 
12.8 


30 
13.2 


35 
13.8 


39 
14.2 


43 
14.7 


47 
15.1 


52 
15.6 


56 
16.1 


61 
16.5 


65 
17.0 


69 
17.5 


74 
17.9 


7S.0 
18.4 


21.16 


21.20 


27 
12.3 


31 
12.8 


36 
13.2 


40 
13.8 


44 
14.2 


48 
14.7 


53 
15.1 


57 
15.6 


62 
16.1 


66 
16.5 


70 
17.0 


75 
17.5 


79 
17.9 


21,20 


21.24 


27 
11.8 


31 
12.3 


36 
12.8 


40 
13.2 


44 
13.8 


48 
14.2 


53 
14.7 


57 
15.1 


62 
15.6 


66 
16.1 


70 
16.5 


75 
17.0 


79 
17.5 


21.24 


21 29 


28 
11.4 


32 
U.8 


37 
12.3 


41 
12.8 


45 
13.2 


49 
13.8 


54 
14.2 


58 
14.7 


63 
15.1 


67 
15.6 


71 
16.1 


76 
16.5 


80 
17.0 


21,29 


21.33 


28 
10.9 


32 
11.4 


37 
11.8 


41 
12.3 


45 
12.8 


49 
13.2 


54 
13.8 


58 
14.2 


63 
14.7 


67 
15.1 


71 
15.6 


76 
16.1 


80 
16.5 


21,33 


21.38 


28 
10.4 


32 
10.9 


37 
11.4 


41 
11.8 


45 
12.3 


49 
12.8 


54 
13.2 


58 
13.8 


63 
14.2 


68 
14.7 


72 
15.1 


77 
15.6 


80 
16.1 


21,38 


21.42 


29 
9.9 


33 
10.4 


38 
10.9 


42 
11.4 


46 
11.8 


50 
12.3 


55 
12.8 


59 
13.2 


64 
13.8 


68 
14.2 


72 

14.7 


77 
15.1 


81 
15.6 


21 .42 


21.47 


29 
9.5 


33 
9.9 


38 
10.4 


42 
10.9 


46 
11.4 


50 
11.8 


55 
12.3 


59 
12.8 


64 
13.2 


69 
13.8 


73 
14.2 


77 
14.7 


81 
15.1 


21.47 


21.51 


30 
9.0 


34 
9.5 


39 
9.9 


43 
10.4 


47 
10.9 


51 
11.4 


56 
11.8 


60 
12.3 


65 
12.8 


69 
13.2 


73 
13.8 


78 
14.2 


82 
14.7 


21.51 


21.56 


30 

8.5 


34 
9.0 


39 
9.5 


43 
9.9 


47 
10.4 


51 
10.9 


56 
11.4 


60 
11.8 


65 
12.3 


70 
12.8 


73 
13.2 


78 
13.8 


82 
14.2 


21,56 


21.60 


30 
8.0 


34 

8.5 


39 
9.0 


43 
9.5 


47 
9.9 


51 
10.4 


56 
10.9 


60 
11.4 


65 
11.8 


70 
12.3 


74 
12.8 


79 
13.2 


83 
13.8 


21,60 


21.64 


31 

7.6 


35 
8.0 


40 

8.5 


44 
9.0 


48 
9.5 


52 
9.9 


57 
10.4 


61 
10.9 


66 
11.4 


70 
11.8 


74 
12.3 


79 
12,8 


83 
13.2 


21,64 


21.69 


31 
7.1 


35 
7.6 


40 
8.0 


44 
8.5 


48 
9.0 


52 
9.5 


57 
9.9 


61 
10.4 


66 
10.9 


71 
11.4 


75 
11.8 


80 
12.3 


83 
12.8 


21.69 


21.73 


32 
6.7 


36 
7.1 


41 

7.6 


45 
8.0 


49 

8.5 


53 
9.0 


58 
9.5 


62 
9.9 


67 
10.4 


71 
10.9 


75 
11.4 


80 
11.8 


84 
12.3 


21,73 


21.78 


32 
6.2 


36 
6.7 


41 

7.1 


45 
7.6 


49 
8.0 


53 
8.5 


58 
9.0 


62 
9.5 


67 
9.9 


71 
10.4 


76 
10.9 


81 
11.4 


84 
11,8 


21 .78 


21.82 


32 
5.7 


36 
6.2 


41 

6.7 


45 
7.1 


49 
7.6 


53 
8.0 


58 
8.5 


62 
9.0 


67 
9.5 


72 
9.9 


76 
10.4 


81 
10.9 


85 
11,4 


21.82 


21.87 


33 

5.2 


37 
5.7 


42 
6.2 


46 
6.7 


50 
7.1 


54 
7.6 


59 
8.0 


63 
8.5 


68 
9.0 


72 
9.5 


77 
9.9 


81 
10.4 


85 
10.9 


21.87 


21.91 


33 

4.7 


37 
5.2 


42 
5.7 


46 
6.2 


50 
6.7 


54 
7.1 


59 
7.6 


63 
8.0 


68 

8.5 


73 
9.0 


77 
9.5 


82 
9.9 


85 
10,4 


21.91 


21.96 


34 

4.2 


38 
4.7 


43 
5.2 


47 
5.7 


51 
6.2 


55 
6.7 


60 
7.1 


64 
7.6 


69 
8.0 


73 

8.5 


77 
9.0 


82 
9.5 


86 
9.9 


21.96 


22.00 


34 

3.8 


38 
4.2 


43 

4.7 


47 
5.2 


51 

5.7 


55 
6.2 


60 
6.7 


64 
7.1 


69 
7.6 


74 
8.0 


78 
8.5 


83 
9.0 


86 
9.5 


22,00 




18.8 


18.9 


19.0 


19.1 


19.2 


19.3 


19.4 


19.5 


19.6 


19.7 


19.8 


19.9 


20.0 





414 



Ice Cre;am Mixes 



TABLE 74 (Continued). 



standardizing 
table for ice 
cream mix 
No. 9 testing: 



flS. 
I 7 
114. 



00% Fat 
50% M. S. N. F. 
00% Sugar 
50% Gelatin 



40.00% T. S. 



l!asi<; 1000 pounds of 

mix. 
Top and bottom lines : 

Fat tests. 
Si de columns : 

S. N. F. tests. 



In eacii sQuare: 

To)) figure: Pounds butter. 

Center figure: Pounds water. 

Bottom figure: Pounds skim-mllk 
powder. 
(Blanks Indicate none of kind required.) 





18.8 


18 9 


19.0 


19.1 


19.2 


19.3 


19 4 


19 5 


19 6 


19.7 


19.8 


19 9 


20.0 




22 04 


35 
3.3 


39 
3.8 


44 
4.2 


48 
4.7 


52 
5.2 


56 
5.7 


61 
6.2 


65 
6.7 


70 
7.1 


74 
7.6 


78 
8.0 


83 
8.5 


87 
9.0 


22,04 


22.09 


35 

2.8 


39 
3.3 


44 
3.8 


48 
4.2 


52 

4,7 


56 
5.2 


61 
5.7 


65 
6.2 


70 
6.7 


75 
7.1 


79 
7.6 


84 
8.0 


87 
8.5 


22,09 


22 13 


36 
2.4 


40 

2.8 


45 
3.3 


49 
3.8 


53 
4.2 


57 
4.7 


62 
5.2 


66 

5.7 


71 
6.2 


75 
6.7 


79 
7.1 


84 
7.6 


88 
8.0 


22 13 


22 18 


37 
1.9 


41 
2.4 


46 
2.8 


50 
3.3 


54 
3.8 


58 
4.2 


63 
4.7 


67 
5.2 


72 
5.7 


76 
6.2 


80 
6.7 


84 
7.1 


88 
7.6 


22 18 


22 22 


37 
1.4 


41 
1.9 


46 

2.4 


SO 

2.8 


54 
3.3 


58 
3.8 


63 

4.2 


67 
4.7 


72 
5.2 


76 

5.7 


80 
6.2 


85 
6.7 


88 
7.1 


22,22 


22.26 


37 
.9 


42 
1.4 


46 
1.9 


51 
2.4 


55 

2.8 


59 
3.3 


64 
3.8 


68 
4.2 


73 
4.7 


77 
5.2 


80 
5.7 


85 
6.2 


89 
6.7 


22 26 


22.31 


38 
.5 


43 
.9 


47 
1.4 


51 
1.9 


55 

2.4 


59 

2.8 


64 
3.3 


68 
3.8 


73 
4.2 


77 
4.7 


81 
5.2 


86 
5.7 


89 
6.2 


22,31 


22.36 


38 


43 
.5 


47 
.9 


51 
1.4 


55 
1.9 


60 

2.4 


65 

2.8 


68 
3.3 


74 
3.8 


78 
4.2 


81 

4.7 


86 
5.2 


89 
5.7 


22 36 


22.40 


1.3 
43 


44 


48 
.5 


52 
.9 


56 
1.4 


60 
1.9 


65 
2.4 


69 

2.8 


75 
3.3 


78 
3.8 


81 
4.2 


87 
4.7 


90 
5.2 


22,40 


22.44 


2.5 
46 


1.3 
47 


48 


52 
.5 


56 
.9 


61 
1.4 


66 
1.9 


69 
2.4 


75 
2.8 


79 
3.3 


82 
3.8 


87 
4.2 


90 
4.7 


22,44 


22.49 


3.8 
49 


2.5 
50 


1.3 
51 


52 


57 
.5 


61 
.9 


66 
1.4 


70 
1.9 


76 
2.4 


79 
2.8 


82 
3.3 


88 
3.8 


91 
4.2 


22 49 


22.53 


5.0 
53 


3.8 
54 


2.5 
55 


1.3 
56 


57 


62 
.5 


67 
.9 


70 
1.4 


76 
1.9 


80 
2.4 


83 
2.8 


88 
3.3 


91 
3.8 


22,53 


22.58 


6.3 
57 


5.0 

58 


3.8 
59 


2.5 
60 


1.3 
61 


62 


67 
.5 


71 
.9 


77 
1.4 


80 
1.9 


83 
2.4 


89 

2.8 


92 
3.3 


22.58 


22.62 


7.5 
61 


6.3 
62 


5.0 
63 


3.8 
64 


2.5 
65 


1.3 
66 


67 


72 
.5 


77 
.9 


80 
1.4 


84 
1.9 


89 
2.4 


92 
2.8 


22.62 


22.67 


8.8 
65 


7.5 
66 


6.3 
67 


5.0 

68 


3.8 
69 


2.5 
70 


1.3 
71 


72 


7S 
.5 


81 
.9 


84 
1.4 


90 
1.9 


93 

2,4 


22,67 


22.71 


10.0 
70 


8.8 
71 


7.5 
72 


6.3 
73 


5.0 

74 


3.8 
75 


2.5 
76 


1.3 

77 


78 


81 
.5 


85 
.9 


90 
1.4 


93 
1,9 


22,71 


22.76 


11.3 
72 


10.0 
73 


8.8 
74 


7.5 
75 


6.3 
76 


5.0 

77 


3.8 

78 


2.5 
79 


1.3 
80 


81 


85 
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91 

.9 


94 

1,4 


22,76 


22 80 


12.5 
76 


11.3 

77 


10.0 

78 


8.8 
79 


7.5 
80 


6.3 

81 


5.0 

82 


3.8 
83 


2.5 

84 


1.3 

85 


86 


91 

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94 
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22 80 


22 85 


13.8 
80 


12.5 
81 


11.3 
82 


10.0 
83 


8.8 
84 


7.5 
85 


6.3 

86 


5.0 

87 


3.8 

88 


2.5 
89 


1.3 
90 


91 


95 
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22,85 


22 89 


15.1 
83 


13.8 
84 


12.5 
85 


11.3 
86 


10.0 

87 


8.8 
88 


7.5 
89 


6.3 
90 


5.0 
91 


3.8 
92 


2.5 
93 


1.3 
94 


95 


22,89 




18.8 


18 9 


19.0 


19.1 


19 2 


19.3 


19.4 


19.5 


19 6 


19.7 


19.8 


19.9 


20.0 





Compositions of Mixes 415 

TABLES FOR COMPOUNDING, UPON 1000 POUND BASIS, ICE 

CREAM MIXES OF VARIOUS TESTS AND FROM VARIOUS 

RAW PRODUCTS. 

Tables 75 to 84 inclusive, immediately following give the 
pounds of various commonly available raw products necessary 
to mix together, in order to produce ice cream mixes of the 
compositions indicated. Tiie tables are all made upon the 1000 
pound basis. The proportions will of course hold for any quan- 
tity desired, either greater or smaller than 1000 pounds. The 
accuracy of the tests of the various mixes is limited to the 
accuracy in the composition of the products used, as compared 
with the composition named in the tables. This method can be 
depended upon to give only approximate results. It is not recom- 
mended when accuracy is desired, nor when the aim is to make 
a uniformly standardized product. 

The heading over each table enumerates the products used. 
The products used are also given upon the left hand side of the 
table, together with the composition of the same. The composi- 
tion of the nine different mixes giving the fat, M. S. N. F., sugar, 
gelatin and total solids is found in the upper half of the table. 
The pounds of the various products necessary to use to make 
1000 pounds of mix, are given in the lower half of the table. 

The various combinations of products used in the several 
tables are as follows : 

Table 75. Mixes of nine compositions ; made from 18 per 
cent cream ; evaporated milk testing 8.00 per cent fat and 26.15 
per cent total solids ; whole milk ; sugar ; gelatin and water. 

Table 76. Cream ; plain 8 per cent condensed whole milk ; 
whole milk; sugar and gelatin. Butter necessary in two compo- 
sitions of mix. 

Table 77. Cream ; plain 9 per cent condensed whole milk .- 
whole milk ; sugar and gelatin. Butter necessary in two compo- 
sitions of mix. 

Table 78. Cream ; plain condensed skim-milk ; whole milk ; 
sugar and gelatin. 

Table 79. Skim-milk powder; butter; sugar; gelatin and 
water. 



4l6 icE Crkam Mixes 

Table 80. Sweetened condensed whole milk; cream; skim- 
milk powder ; butter ; whole milk ; sugar and gelatin. 

Table 81. Sweetened condensed skim-milk ; cream ; butter ; 
whole milk ; sugar and gelatin. 

Table 82. Skim-milk powder; whole milk; butter; sugar 
and gelatin. 

Table 83. Sweetened condensed skim-milk ; cream ; sugar ; 
gelatin and water. 

Table 84. Sweetened condensed skim-milk ; butter ; sugar ; 
gelatin and water. 

METHOD OF CALCULATION USED IN DERIVING INGREDIENT 

FORMULAS. 

J. A. Cross devised a unique method of calculation that was 
applied in solving all the problems included in Tables 75 to 81 
inclusive. This method can be applied to any combination of 
substances that it may be desired to use in making up ice cream 
mix. 

The example used to illustrate the method is taken from 
Table 75 and is as follows : — 

Example: Wanted to make 1000 pounds of ice cream mix 
testing 8.00 per cent fat; 11.50 per cent M. S. N. F. ; 13.00 per 
cent sugar, and .50 per cent water free gelatin. The materials 
available are cream testing 18.00 per cent fat, and 25.59 per cent 
T. S. ; evaporated milk testing 8.00 per cent fat, and 26.15 per 
cent T. S. ; whole milk testing 3.50 per cent fat and 12.00 per 
cent T. S., sugar testing 100 per cent T. S. ; and gelatin testing 
87.00 per cent T. S. 

Solution: Each 1000 pounds of mix must contain 130 pounds 
of sugar and 5 pounds of gelatin. Therefore 1000 — (130-)-5): 
865 pounds of milk products. The 865 pounds of milk products 
must contain 80 pounds of fat and 115.7 pounds of M. S. N .F. 
(The extra .7 pounds is added to make up for the water contained 
in the gelatin used. 5 — (5X-87)=r.65. 

80-^865^:9.25, per cent fat required in mixture of milk 
products. 



Compositions of Mixes 417 

115.7-^865=13.39, per cent M. S. N. F. in mixture of milk 
products. 
The tests of the cream, evaporated milk and whole milk 
respectively are plotted upon the basis of their fat and S. N. F. 
contents, and lines are drawn from the one to the other to form 
a triangle. The test of the mixture required is then plotted within 
the triangle. The other lines are then drawn, all being as 
illustrated under Fig. 89. Accurate measurements are made of 
each full line that intersects the point of the mixture inside of 
the triangle, and in turn of the short line which extends from the 
central point to one of the sides of the triangle. The larger the 
triangle the more accurate these measurements will be, and when 
many determinations of this kind require to be made, a drawing 
board and T square can be used to advantage. By simple ratio 
the proportion of each ingredient required is calculated as 
follows : — 



A^D 1.046 cm. 1.046 



A^A 4.494 cm. 4.494 



B^D .7819 cm. .7819 



B^B 3.246 cm. 3.246 



C^D 1.7213 cm. 1.7213 



C^C 3.273 cm. 3.273 



1000 lbs. of mix require 



of 865=201.3 pounds cream re- 
quired. 



of 865=208.8 pounds milk re- 
quired. 



of 865=454.9 pounds evapo- 
rated milk re- 
quired. 
130.0 pounds sugar 
5.0 pounds gelatin. 



Total, 1000.0 pounds mix. 



„ I 7.994 per cent fat. 
\ 32.99 per cent T. S. 



418 



icE Cre;am Mixes 

















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Fig" 89. Diagram Showing* Graphic Method of Standardization. 



In the above diagram point A, representing cream testing 18 per cent fat 
and 7.59 per cent 8. N. F., is plotted as indicated. Point B, representing whole 
milk testing 3.5 per cent fat and 8.5 per cent S. N. F., and point C, represent- 
ing evaporated milk, testing 8 per cent fat and 18.15 per cent S. N. F., are 
plotted in the same way. These three points are then connected to form the 
triangle ABC. Point D represents the mixture desired, testing 9.35 per cent 
fat and 13.39 per cent S. N. F. l>ines are then drawn tlirough AD, BD and 
CD to the point where they intersect the side of the triangle. The ratio of 
A, D to A, A times 865 represents the pounds of cream required. The ratio 
of B,D to B,B times 865 represents the pounds of whole milk required and the 
proportion of C,D to C,C times 865 represents the pounds of evaporated milk 
required. Adding these three amounts, and the sugar and gelatin necesary, 
the sum will be 1,000 pounds. 



Mixes of Nine Compositions 



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CO 


d 


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o 
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00 

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8 


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c 
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Mixe;s of Nine Compositions 



m 



o 

















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o 


o 


o 


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CO 
73 


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c 














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cc 


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o 


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o 


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c 


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424 



IcK Cream Mixes 



^ .2 





PQ 


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s 


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CO 

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6 
2 


Per 
cent 
18.00 


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c 

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CO 
CO 




CO 
CO 




2 


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8 


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02 

c 

3 

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PL, 


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00 
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cs 




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c 

3 

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c 

3 

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10 


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10 





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CO 
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CO 

g 
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CO 
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CO 




10 


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CO 


m 

C 

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CO 


CO 
CO 


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CO 
CO 


to 
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C 
3 
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Ph 


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00 


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c a 
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5^ 

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3 C 
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Mixes of Nine Compositions 



425 



bfl 
3 
Xfi 



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m ^ 
C CO 



o 



O) O 








Per 

cent 
18.00 


o 


CO 


o 


d 


03 

c 

3 

o 


d 


CO 


o 

CI 




d 


d 


i 




o 


o 
o 

fO 


o 


o 
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00 
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o 


00 


00 


CO 




d 


lO 


o 




o 

02 


CO 


o 


d 

CO 


CO 

-o 

3 
3 

o 

Oh 


CO 


CO 

CO 
CO 




CO 

00 


00 


»o 


o 


CO 




o 

t>0 


CO 


o 


8 

CO 


02 

3 
3 

o 


<M 


o 




00 


CO 


lO 


d 






o 
d 


CO 


o 


00 


03 

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3 

o 

Oh 


CO 

CO 


00 




d 

CI 


t^ 


d 


i 




S 


o 

<=> 

CO 


o 

lO 


CO 


3 
3 
O 
Oh 


o 


05 
CO 




CO 
CO 


CO 


d 


§ 


CO 


0. goo 


o 

o 


CO 


o 

lO 


CO 


to 

3 
3 
O 


lO 


d 
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CO 

CO 


03 
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CO 


lO 


o 


C<1 


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o 

CO 


o 


o 
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CO 


CO 

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3 
3 
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00 


00 

CO 

CO 




d 

CO 


00 


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d 

8 


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o 


CO 


o 


CO 
CO 


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CD 

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CO 




d 
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CD 
CO 


d 


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c 




m 




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00 


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g 


CC 










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bC 

m 


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o ir; 




3 


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111 


i, O (. 


3 
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! 

r 

3 









426 



Ice Cream Mixes 



o 



o 






Tl 


, 


e 




rt 


ot 




ea 


>-i 


n 


c4 




3 
CO 






© 




§ 



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w o 



p t= 



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o 

















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1 










1 




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o 


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o 


o 


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05 


in 1 CO 

















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d 


d 







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t>. 


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d 


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^ 




CO 


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2 
















01 
















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o 


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c 














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d 


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d 




CO 


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CO 




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tc 


















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o 


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o 


o 


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1— 1 


CO 


CO 













h c 


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o 


c 














t^ 














o 


d 


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d 


10 


d 




(M 


05 


Tt< 




CD 


CO 





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CO 




t^ 


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M 
















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c 














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10 







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cc 
















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q 




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K 


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83 
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c 






























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c 










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a 


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m 
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tt 


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c 












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c3 t. D, s- 














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S 
o 










1 




















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U 












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1 



Mixes of Six Compositions 



427 



o 



■^ hj 





o 




8 




s 

d 


Tti 




° 




o 
o 

CD 

CO 


3 

o 




o 

s 

1— 1 


CO 
CO 


d 


o 


00 

d 


i 




"O 


^1 


8 

(M 


o 

00 


8 


o 


o 
o 

d 
CO 


02 

s 

3 

o 


00 


00 

CO 
CO 


05 

00 


o 


CO 


i 




•* 




O 
O 

d 


o 
o 


o 
o 


o 


CO 


03 

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c 

o 


00 

CO 


00 


CO 


o 


t^ 


o 




CO 


l| 


8 

05 


o 


8 

CO 


° 


o 

o 

CO 


CO 

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c 

o 


o 

00 




CO 
d 


o 


i 


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IM 


II 


00 


o 

o 


o 
o 

CO 


o 


CO 


03 

c 

3 

o 


CO 


00 


CO 


o 


CM 


o 




- 


S3C 


o 
o 

00 


o 


CO 


o 


CO 
CO 


CO 

3 

o 


CO 


CO 
CO 


CO 


o 


CM 


i 




'a 

6 
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3 


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-2 

m 
o 


ai 

H 


&*? 


d 


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1 


8 

00 










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05 


















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o 


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: 




a 

lU 

o 

;-i 

s. 

m 
0) 

1 

O 

a 

o 
O 


CO 

c : 


i 

o 


>-• 
OS 


'-(3 

o 




"3 
o 










'of 

cc ■- 

CO P 

"St 

s >■ 


J3 

< o < 


r 







428 



Ice Cream Mixes 

TABLE 84. 



Mixes of Thiee Compositions. Made from Sweetened Condensed Skim-Milk, 
Butter, Sugar, Gelatin and Water. 1000 lb. Basis. 









No. of Mix 


1 


2 


3 




Fat 


Per Cent 
12.00 


Per Cent 
16.00 


Per Cent 
18.00 


Composition of Mixes in Percentage.? 


M. S. N. 


F 


8.50 


7.50 


7.50 




Sugar 


14.00 


14.00 


14.00 




Gelatin 


.50 


.50 


.50 




T. S 


35.00 


38.00 


40.00 




Sweet 

Condensed.. . 
Skim-milk. . . 


Fat 


M.S.N.F. 


T. S. 


Pounds 


Pounds 


Pounds 


Name and tests of 
products with 
pounds of each 
required 


% 
.50 


% 
27.50 


% 
70.00 


303.5 


264.6 


263.6 


Butter 


83.00 


1.50 


84.5 


142.8 


191.4 


215,0 


Su^ar 






100. 


12.5 


28.9 


29.3 




Gelatin 






87. 


5.0 


5.0 


5.0 




Water 









536.2 


510.1 


487.1 




Total 








1000 


1000 


1000 



TABLE FOR COMPOUNDING ICE CREAM MIXES IN VACUUM PAN. 

Tables 85 to 87 inclusive each in turn give the pounds of 
three different combinations of raw materials, necessary to pro- 
duce nine different compositions of ice cream mix. These are all 
calculated upon basis that will yield 1,000 pounds of finished prod- 
uct, when condensed to the concentration desired; in the vacuum 
pan, using the Mojonnier method. The proportions given will 
apply to any size of batch of finished product that may be wanted 
either larger or smaller than 1,000 pounds. 

The arrangement of the tables is similar to that followed in 
the tables just preceding. 

The combination of products used was as follows : 

Table 85, Whole milk, butter, sugar and gelatin. 

Table 86, Whole milk, butter, sugar and gelatin. 

Table 87, Skim-milk, butter, su^ar and gelatin. 



Mixes of Nine; Compositions 



429 



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432 



Ice Cream Mixes 



REFERENCES 

1 Richmond, H. D. Dairy Chemistry p. 335. 

2 Hammer, B. W. & Johnson, A. R. The specific heat of milk and milk 
derivatives. Research Bui. No. 14, Ames, Iowa. 

' Bogue, R. H. and Skinner, W. W. Relative sweetness of sweet sugar, 
Jour. Ind. Eng. Chem. Vol. 14, 1922, p. 522. 

6 Cromley, Roy H. Chief Chemist, Stroh Products Co. Article in Ice 
Cream Trade Journal. 

"Heller's Guide for Ice Cream makers, B. Heller & Co., Chicago. 

■ Analysis made by Miss Lucy Klein, Research Laboratories, Mojonnier 
Bros. Co., Chicago, 111. 

* Sample received by courtesy of Horine and Bowey Co., Chicago. 

"Atwater, W. O. and Bryant, A. P. Bui. No. 28, 1906. Office of Exp. Sta., 
Washington, D. C 

^'' Mojonnier, T. 

^ Bothell, F. H. Pacts about sandy ice cream. Ice Cream Trade Journal, 
Feb. 1920. 

^- Bothell, F. H. Sandy Ice Cream and its cause. Creamery & Milk Plant 
Monthly, June, 1921. 

18 Zoller, H. F. and Williams, O. E. Creamery and Milk Plant Monthly, 
October, 1921. 

1* Williams, O. E. Progress in studying causes of sandy ice cream. 
Creamery and Milk Plant Monthly, Nov. 1921. 

18 Groth, P. Chem. Krystallsgraphic. Teil 3, p. 804, 1910. Leipzig. 

i« Dubrunfaut, Compt. Rend. Vol. 42, p. 228, 1856. 

"Hudson, C. S. Jour. Amer. Chem. Soc. 1904, Vol. 26, p. 1065 and 1908, 
Vol. 30, p. 1767. 

18 Solliard, E. Chemie et Industrie, Sept. 1919. 

i» Mack, Edw. and Liedel, H. J. Thesis — The solubility of milk sugar. 
H. J. Liedel, Ohio State University, 1920. 

^^ Travis, R. P. The final solubility of lactose in a representative ice 
cream mix, and in a fourteen per cent solution of pure sucrose. Thesis for 
M. S. degree. Graduate School, Cornell University, Ithaca, N. Y., 1922. 

21 Hall, Thos. Ice Cream Trade Journal, New York, N. Y., Nov. 1921, p. 72. 

22 Mojonnier, T. and Mojonnier, J. J. 

28 Peterson, R. W. and Tracy, D. H. The Condensation Process of Pre- 
paring an Ice Cream Mix, Jour. Dairy Science, Vol. V, 1922, p. 273. 



CHAPTER XIV 

THE STANDARDIZATION OF 

MISCELLANEOUS DAIRY 

PRODUCTS 

In addition to the products described in the preceding chap- 
ters, there are numerous others of great commercial and economic 
importance that require the most exact control possible in their 
manufacture, if these are to be marketed of uniform chemical and 
physical properties. The standardization of the most important 
of these products will be discussed in this chapter. 

THE STANDARDIZATION OF UNSWEETENED CONDENSED 

MILK. 

Besides evaporated milk described in Chapter XI, there are 
several other unsweetened condensed milk products of great com- 
mercial importance, the same being made both of skim and whole 
milk. There are two main varieties of concentrated skim-milk. 
One variety is controlled by a Federal Standard of 20.00 per cent 
T. S., and is canned largely in one gallon cans, and sterilized like 
evaporated milk. 

The second variety is manufactured largely under a trade 
standard of 25.50 per cent T. S., and is usually superheated in the 
vacuum pan. This is marketed largely in eight or ten-gallon milk 
shipping cans, the same being an unsterilized product, and in- 
tended for prompt consumption. 

The fat content in these products is frequently disregarded 
but under careful management the same should be determined, 
otherwise preventable losses may occur. The standardization is 
usually based upon the T. S. content only. 

Evaporated skim-milk of 20 per cent T. S. test is condensed in 
the vacuum pan in a manner similar to evaporated whole milk. 
The condensation is continued sufficiently to provide an excess 

[433] 



434 Miscellaneous Dairy Products 

of T. S. in the condensed product. This is then tested for T. S. 
using the Mojonnier Tester, and water is added to bring the 
product back to the test desired. 

Plain condensed skim-milk testing 25.50 per cent T. S. is usu- 
ally condensed beyond the point desired before superheating. 
The overcondensed product is diluted back with water to the 
point desired as in the case of the evaporated skim-milk. 

If the skim-milk used is properly sampled and tested the yield 
can be calculated as indicated by the following example : The 
batch contains 10000 pounds skim-milk testing 8.80 per cent T. S. 
It is desired to make evaporated skim-milk testing 20.00 per cent 
T. S. The product obtained from the pan weighed 4200 pounds. 
10000 X .088 = 880, pounds T. S. in the entire batch. 

880 ^ .20 = 4400, the pounds of evaporated skim-milk pos- 
sible to make. 
4400 — 4200 = 200, or the pounds of water necessary to add. 

If the standardizing is to be done after condensing, the calcu- 
lation is indicated by the following example : 

The product from the pan weighs 3200 pounds, and tests 26.87 
per cent T. S. 

The test desired is 25.50 per cent T. S. 
32.00 : X=25.50 : 26.87. 

X = 3451, the total pounds that the batch should contain. 
3451 — 3200 := 251, the pounds of water necessary to add. 

Plain condensed whole milk is manufactured under many dif- 
ferent trade standards, as regards both fat and T. S. The two 
most common standards are 6.00 per cent fat and 28.00 per cent 
T. S. and 8.00 per cent fat and 30.00 per cent T. S. The methods 
of calculation for standardizing these products are the same as 
in the case of evaporated milk given under Chapter XI, to which 
the reader is referred. 

RELATION OF COMPOSITION, TEMPERATURE AND SPECIFIC 

GRAVITY IN SEVERAL UNSWEETENED CONDENSED 

MILK PRODUCTS. 

It is pointed out in the chapter on evaporated milk that a 
proper knowledge of the relation between temperature, specific 
gravity and composition is of value in determining the point at 
which to strike the batch. A knowledge of this relation may also 



MitK Powders 435 

be used to advantage in determining the striking point of other 
concentrated milk products. With the object in view of providing 
this useful information, the specific gravity at various tempera- 
tures and compositions was carefully determined in the case of 
three of the most common unsweetened condensed milk products. 
Fig. 90 shows this relation in the case of unsweetened con- 
densed whole milk in which the fat and M. S. N. F. are in the 
ration of 8 : 22. Fig. 91 applies to plain condensed skim-milk 
ranging from 20.00 per cent to 40.00 per cent T. S. Fig. 92 
applies to condensed buttermilk testing from 13.50 per cent to 
32.00 per cent T. S. All tests were made by J. A. Cross and H. 
J. Liedel. 

THE STANDARDIZATION OF MILK POWDERS. 

Milk powders are manufactured of various compositions from 
skim-milk to cream. In skim-milk powder the per cent of fat is 
ordinarily disregarded, but sometimes this is considerable — the 
closeness of the separation of the whole milk being the governing- 
factor. As a matter of precaution in factory control, the fat test 
of the skim-milk should be daily ascertained both in the fresh 
skim-milk, and in the finished powder. The water content of skim- 
milk powder is limited in the Federal standard to 5 per cent. 

The test must be closely watched both because of the standard 
requirements, and because of the close relation between water 
content and keeping quality. 

The following example shows how to calculate the pounds of 
skim-milk powder possible to make. The batch of skim-milk 
weighs 10000 pounds and tests 8.80 per cent T. S. 
10000 X .088 = 880, pounds T. S. in entire batch. 

880-:- .95 == 927. pounds skim-milk powder testing 95.00 per 
cent T. S. that it is possible to make. 

The sampling and the testing of the powder itself is fully de- 
scribed in the chapters relating to this subject. 

HOW TO STANDARDIZE WHOLE MILK AND CREAM POWDERS. 

The principles underlying the standardization of whole milk 
powder are very similar to those underlying the standardization 
of evaporated milk. Two general methods are available, namely, 
(1) standardizing the whole milk in the hot wells before condens- 
ing, or (2) standardizing the finished product by adding skim- 



436 



MiscRij^ANEous Dairy Products 
KEY TO FIG. 90 



Curve 


1 


2 


3 


4 


5 


6 


7 


Fat, 

per cent . . 


5.0 


5.50 


6.00 


6.50 


7.00 


7.50 


8.00 


M. S. N. F. 
per cent . . 


13.75 


15.13 


16.50 


17.88 


19.25 


20.63 


22.00 


T. S., 

per cent . . 


18.75 


20.63 


22.50 


24.38 


26.25 


28.13 


30.00 




SPEC/r/C GRA virr/N PE0/=^EE5 baume 



Pig". 90. Relation Between Temperature, Specific Gravity and Composi- 
tion in the case of unsweetened condensed wliole milk in which the Constitu- 
ents are in the Ratio 8.00 Per Cent Pat to 22.00 Per Cent M. S. N". P. 

milk powder or whole milk or cream powder as the case may re- 
quire. The first named method is usually preferable, for the rea- 
sons that the proper products are not always available, and that 
many plants are not equipped to mix, satisfactorily, various 
grades of milk powder. 

Whole milk powder is marketed under many different compo- 
sitions. The minimum composition is governed by the Federal 
ruling which calls for not less than 26.00 per cent fat. ^9.00 per 



Condensed Skim-Milk 



437 




6RA 



VITY 



DEGREES BAUME 



Pig". 91. Kelation Between Temperature, Specific Gravity and Composi- 
tion in the Case of Plain Condensed Skim-milk Ranging- from 20.00 Per Cent 
to 40.00 Per Cent T. S. 



cent M. S. N. F., and not more than 5 per cent water. In this 
product the ratio of M. S. N. F. to fat is 1 : 376S. 

When necessary to add skim-milk to the whole milk, when 
standardizing before condensing, follow method of calculation 
recommended under Problem 7, Chapter XII. 

When necessary to add cream to the whole milk, when stand- 
ardizing before condensing, follow the method of calculation rec- 
ommended under Problem 8, Chapter XII. 

When desired to standardize whole milk powder with other 
milk powders, follow methods of calculation recommended under 
Problems 1 and 2, Chapter X. 

In cream pow^der the per cent of M. S. N. F. and the physical 
properties of the product will vary with the composition of cream 
used to make the powder. Table 88 gives the percentage of 
M. S. N. F. in the T. S. of three samples of cream of different 
compositions. 



438 



MiscELtANKous Dairy Products 



^W 



Tff 



TOTAL SOLIDS 
13. 50% 20. 00% 25.00% 32.00% 




SFEC/FJC 6f^/\VITY-D£0REE5 BAUME 



Pig-. 92. Relation Between Temperature, Specific Gravity and Composi- 
tion in the Case of Condensed Buttermilk Bang'ing' from 13.50 Per Cent ta 
32.00 Per Cent T. S. 

TABLE 88. 

Per Cent M. S. N. F. in T. S. of Cream of Different Tests. 



Composition of Cream in Per Cent 


Per Cent 
M. S. N. F. of 


Fat 


M. S. N. F. T. S. 


T.S. 


15.15 


7.85 


23.00 


34.13 


30.03 


6.48 


36.50 


17.75 


50.02 


4.63 


54.65 


8.47 



It is evident that the composition of cream powder depends 
entire!}' upon the composition of the cream from whicli it is 
produced. A cream low in fat will produce a cream powder high 
in S. N. F. and vice versa, 

MANUFACTURE, COMPOSITION AND STANDARDIZATION OF 
CHOCOLATE, COCOA AND MILK CHOCOLATE. 

Chocolate and cocoa are made from the seeds of Theobroma 



Chocolate and Cocoa 439 

Cacao, a tree that grows in most tropical countries. The seeds 
are commonly called "cocoa beans." 

In the manufacture of chocolate the seeds are separated from 
the pulp of the fruit in which they groM\ Then they are roasted, 
partially crushed and winnowed to remove the seed shells. The 
partially crushed seeds after having the shells removed are known 
as cocoa nibs. In the manufacture of chocolate these are crushed 
warm between grinding stones, and the freed fat causes the ma- 
terial to flow from the grinding stones in the form of a thin paste. 
This is allowed to cool in molds and forms commercial unsweet- 
ened chocolate. It has practically the same composition as the 
cocoa nibs from which it is made. 

The sweetened chocolate usually contains between 50 and 70 
per cent of added sugar, and the percentages of the other con- 
stituents are correspondingly lower. 

Cocoa is made from the ground cocoa nibs, or unsweetened 
chocolate by separating part of the fat, usually about one-half. 
The removal of the fat increases proportionately the percentage 
of the other constituents remaining in the cocoa. 

In the manufacturing process cocoa shells may not be com- 
pletely separated from the cocoa nibs before they are ground, but 
any large amount of material from the shells remaining in the 
chocolate, or in cocoa Avould be classed as an adulteration. 

Winton analyzed cocoa nibs, pure commercial cocoa, and co- 
coa shells, and his results are given in the following table. 

Milk chocolate consists of material from ground cocoa nibs 
with added sugar, and milk or milk products. The composition 
of ten samples of milk chocolate is given in the Annual Report of 
the Conn. Agr. Exp. Sta. for 1911. Each sample was taken from 
the product placed on the market by a dififerent manufacturer. 
These analyses are given in Table 89. 

A sample of milk chocolate obtained upon the Chicago market 
was tested by Miss Lucy Klein and found to contain 32.66 per 
cent fat, and 2.38 per cent water. 

The results given in Table 90 indicate the wide differences in 
composition that were found in milk chocolate. By proper 
methods of standardization, these diiferences could be greatly re- 
duced. 



440 Miscellaneous Dairy Products 

TABLE 89 
Composition of Cocoa Nibs, Pure Commercial Cocoa and Cocoa Shells. 





Cocoa nibs 

(hand shelled) 

Average of. 17 

analyses. 

% 


Pure commer- 
cial cocoa. Av- 
erage of 26 an- 
alyses. 

'% 


Cocoa shells 

(hand shelled) 

Average of 17 

analyses. 

% 


Water 

Ash 


2.72 
3.32 
1.04 
0.40 

12.12 
2.64 
8.07 

19.57 
50.12 


6.23 
5.49 
1.15 
0.16 

18.34 

4.48 

11.14 

26.33 
26.69 


4.87 
10.43 


Theobromin 


0.49 


Caffein 


0.16 


Other nitrogenous substance 
(Protein) 


14.46 


Crude fiber 


16.55 


Pure starch 


4.13 


Other nitrogen-free sub- 
stances 


46.15 


Fat 


2.76 








100.00 


100.00 


100.00 



TABLE 90 

Composition of Milk Chocolate. 



In Air-Drv Material 



Sam- 
ple 
No. 


Ash 
per 
cent 


1 


1.56 


2 


1.85 


3 


1.71 


4 


1.67 


5 


1.56 


6 


1.79 


7 


2.12 


8 


1.66 


9 


1.60 


10 


2.25 



Alkalinity 

of ash 

0. c. of 

N/10 acid 

per gram 

of chocolate 



1.19 
1.82 
2.09 
1.93 



58 
10 
49 
89 
92 



1.75 



Fat 
per 
cent 



29.95 
28.69 
32.13 
28.77 
28.85 
33.23 
26.84 
33.31 
32.67 
30.63 



Nitro- 
gen 
per 
cent 



1,17 
1 . 36 
1.19 
1.11 
1.17 
1.42 
1.44 
1.20 
1.29 
1.55 



Sucrose 
per 
cent 



48.31 
45.81 
43.09 
49.45 
49.65 
39.45 
44.26 
42.45 
42.64 
39.49 



Lactose 
per 
cent 



7.28 
7.75 
3.57 
2.25 
6.87 
6.24 
8.46 
7.39 
7.81 
8.17 



Fat Constants 



Iodine 
number 
(Hanus) 



35.60 
31.41 
33.86 
33.35 
34.42 
35.36 
35.16 
34.08 
33.80 
35.30 



Refractive 

Index 
at 40° C. 



1.4566 
1.4567 
1.4567 
1.4569 
1.4562 
1 . 4566 
1.4576 
1 , 4569 
1 . 4562 
1.4563 



Reich- 

ert 
Meissl 

No. 



6.2 
5.9 
5.0 
3.2 
5.6 
4.1 
3.7 
3.7 
5.1 
5.8 



Composition of Products 

TABLE 91. 
Composition of Miscellaneous Milk Foods. 



441 



Per Cents 













Cold 


Starch, 


Malts 


Moisture 


Fat 


Proteids 


Ash 


Water 
Extract 


etc., by 
Difference 


Malted milk .... 


3.98 


7.70 


14.88 


3.12 






Malted milk .... 


2.98 


8.08 


15.18 


3.34 






Malted milk .... 


3.55 


8.36 


15.64 


3.52 






Malted milk .... 


2.68 


8.17 


14.52 


3.34 






Malted milk .... 


2.90 


7.77 


14.96 


2.92 


75.10 




Malted milk .... 


2.50 


8.37 


14.57 


3.48 






Peptogenic milk 














powder 


0.G5 


Trace 


0.81 


1.1] 


89.93 


7.50 


Peptogenic milk 














powder 


0.80 


Trace 


0.52 


1.10 


89.76 


7.82 


Allenbury's Milk 














Food No. 2 


3.92 


15.00 


9.19 


2.60 






Allenbury's Milk 














Food No. 2 


3.10 


1C.27 


9.56 


2.87 


67.45 


0.75 


Allenbury's Milk 














Food No. 2 


3.37 


16.03 


10.04 


2.61 






Allenbury's Milk 














Food No. 2 


4.55 


15.07 


9.30 


3.04 


69.55 




Allenbury's Milk 














Food No. 1 


2.72 


17.80 


10.13 


3.45 


66.50 




Wampole's Milk 














Food 


5.22 


7.87 


12.73 


2.22 


76.55 





Two general methods of standardizing milk chocolate are pos- 
sible. First, mixing the milk products and the sugar in the proper 
proportions in the hot well before condensing in the vacuum pan. 
This mixture is condensed as low as possible in the vacuum pan, 
and finally reduced to the desired consistency in another opera- 
tion. In turn this dried mixture of butterfat, milk solids not fat 
and sugar is mixed and ground with unsweetened chocolate. 
Maintaining a uniform balance between the various ingredients 
that compose the finished milk chocolate will do much to iiisure 
a uniform product. 



442 MiscELLANKous Dairy Products 

Second. The milk products aud the sugar are condensed in 
the vacuum pan to the desired consistency and this condensed 
product is in turn mixed with the cocoa liquor, in the desired 
proportions, and the mixtvire further reduced to the desired con- 
sistency. 

Table 91 gives the composition of various other milk foods, 
as reported by McGill.^ 



1 McGiU, A. Infants' and Invalids' Foods. Inland Revenue Dept., Ot- 
tawa, Canada. Bui. 278, 1914. 



CHAPTER XV 
THE OVERRUN IN ICE CREAM 

GENERAL FACTS REGARDING OVERRUN. 

In tlie process of freezing ice cream mix the volume is increased 
by the expansion of both the solid and liquid constituents com- 
prising the mix, and by the incorporation of innumerable small 
air bubbles. One of the best theories ofifered as the cause for this 
increase in the volume of the ice cream mix is that the walls 
enclosing the air cells become frozen, and thus prevent the escape 
of the air in the cells, so long as the ice cream is kept sufficiently 
cold. When the ice cream is drawn from the freezer it is in a 
plastic condition, and unless hardened soon after drawing the air 
will gradually escape, as the cell walls are not sufficiently rigid to 
retain the enclosed air. 

This important subject has received the attention of many 
investigators, among whom may be especially mentioned Wash- 
burn,^ Baer,- and Mortensen." 

The true percentage of overrun is calculated by the following 
formula : 

Percentage overrun = 
/Weight unit volume mix — weight unit volume ice cream 



X 100 



Weight unit volume of ice cream 
Example in calculating overrun. Ice cream mix weighs 9.10 
pounds per U. S. gallon. The ice cream made from this mix 
weighs 4.55 pounds per U. S. gallon. What is the percentage of 
overrun ? 

Percentage overrun ^1 — '- — IX 100 = 100 per cent overrun. 

\ 4.55 / 
There is no factor in the manufacture of ice cream that fluctu- 
ates more than the percentage of overrun ; therefore, its control is 
of very great importance. Insufficient overrun greatly increases 
the cost of the ice cream, and yields a product that is immediately 
detected by its lieavy and soggy appearance and to some users by 

[443] 



444 



The; Overrun in Ice Cream 



its unpalatable taste. Too high an overrun produces a fluffy prod- 
uct with a flat taste, that stands up poorly in the cabinet of the 
dealer, thereby causing many complaints. 

The aim should be for the manufacturer to adopt a standard 
percentage of overrun, unless this is already done by law, and then 
to control the manufacture of his product, so that this standard 
can be maintained at all times. 

DIFFERENT PHASES IN THE NORMAL FREEZING AND 
HARDENING OF ICE CREAM. 

The normal freezing and hardening period divides itself into 
four separate and clearly defined phases, as shown in the chart 
under Fig. 93. The values given upon the chart were obtained 
from careful experiments made in the plant of the Goodman- 
American Ice Cream Co., Chicago, Illinois, and the same are being 
published through their courtesy. 

The percentage of overrun and the temperature of the ice 
cream were determined at the end of minute periods, beginning 
immediately after the freezing of the mix was started, and con- 
tinuing until the batch Avas dra"\'\Ti from the freezer. The temper- 
ature of the ice cream was determined at larger intervals as in- 
dicated. 

The mix was one testing 18.00 per cent of fat, and 38.00 per 
cent of total solids. 




Tig. 93. 



TIME IN MINUTES HOURS 

Th9 Four Phases in the Normal Freezing- of Ice Cream, 



Phases in Freezing Ice Cream 445 

(1). The specific heat phase, during which the specific heat is 
removed from the mix, and the temperature is lowered to the 
freezing point. This phase begins the instant the mix is drawn 
into the freezer, and ends the instant that the specific heat has 
been all absorbed, and just before the latent heat begins to be 
absorbed. The increase in the overrun during this phase is quite 
appreciable. During this phase the heat to be removed from a 
mix containing 8.00 per cent fat, 34.00 per cent T. S. and 66.00 
per cent water, the initial temperature of which upon entering the 
freezer is 40° F., and which has a freezing point of 28° F., is about 
as follows, calculated upon the basis of 100 pounds of the mix : 

40 — 28 =: 12, or the number of F. degrees that the mix is to be 
lowered. (12 X 100) X -900 — 1080, or number B. T. U. required 
to reduce the mix to freezing temperatures. 

(Note: By specific heat is meant the amount of heat required 
to raise or lower one pound of the mix 1° F. or the equivalent of 
one British thermal unit : = 1 B. T. U.) The above calculation 
is obviously only an approximation, since the specific heat is cal- 
culated upon that of water at 15° C, as shown by the researches 
of Bartoli and Stracciati. The specific heat of water varies at dif- 
ferent temperatures, being 1.000 at 15° C. and 1.00664 at 0° C. 
The specific heats of milk and other products entering into the 
composition of ice cream mix are considerably different than that 
of water, and like water the same vary with the temperature. 
Hammer and Johnson* report extensive investigation relating 
to the specific heat of milk and other dairy products. The average 
specific heat of milk testing 3.50 per cent fat between 0° and 15° 
C. is reported as being 0.939 and of 15.00 per cent cream 0.837. 
The specific heats of ice cream mix of various composition, cal- 
culated from the values reported by Hammer and Johnson, are 
given in Table 44, Chapter XIII. For a mix of the above composi- 
tion it is .900. 

(2). The latent heat phase. 

This phase begins the instant that the latent heat begins to be 
absorbed and ends the instant that the latent heat is all absorbed, 
and just before ice crystals begin to form. During this phase the 
temperature remains practically constant. The viscosity and the 
overrun both increase rapidly during this phase. It may be com- 
pleted while the ice cream is still in the freezer or whenever the 



446 The; Overrun in Ice CrEa 



M 



freezing operation is continued long enough to remove all the 
latent heat. When the freezing operation is stopped before the 
latent heat is all removed, then it is completed after the ice cream 
is drawn from the freezer, and after the ice cream has stood in the 
hardening room for the time necessary to complete the removal 
of the latent heat. The best practice is to complete this phase in 
the hardening room. As soon as it is passed the ice cream passes 
from a highly viscous or plastic condition to a brittle condition, 
due to the freezing of the walls encasing the air. If it is passed 
while the ice cream is in the freezer, there is danger of losing part 
of the overrun. The ice cream should be drawn from the freezer 
near the end of this phase, or as soon as the desired viscosity and 
overrun have been obtained, inside of it. 

During this phase, as pointed out by Cutler"' the number of 
heat units removed is governed to quite an extent by the compo- 
sition of the mix, this being due to the latent heat that is derived 
from the water content only of the mix. In the case of a mix of 
the composition just named, the latent heat removed would be as 
follows : 

100 — 34.00 := 66.00, or per cent water in mix. 
100 X -66 = 66, or pounds water in 100 pounds of mix. 
144 = B. T. U. required to convert one pound of water into one 
pound of ice or vice versa, at 32° F., or the latent 
heat of ice. 
66 X 144 — 9504, or B. T. U. required to remove the latent heat 
from 100 pounds ice cream mix of above composi- 
tion. 

Each one per cent increase or decrease in T. S. would increase 
or decrease the above numbers to the extent of 144 B. T. U. upon 
every 100 pounds of the mix. 

(3). The critical point phase. 

This phase begins the instant that all the latent heat has been 
extracted, and ice crystals begin to form. The ice cream should 
be drawn when the proper viscosity and overrun have been 
obtained just before reaching this phase. Under good practice 
this phase should begin after the ice cream has been drawn into 
the cans, and placed in the hardening room. If passed while the 
ice cream remains in the freezer, the danger of losing overrun 



PROPKR'OVKRRUN IN ICR CrEAM 447 

becomes very large. The temperature will remain nearly constant 
during this phase. 

(4). The hardening phase. This phase begins when the criti- 
cal point phase has been passed. The ice cream during this entire 
phase should be kept in the hardening room at a sufficiently low 
temperature to cause the crystallization of the ice crystals in a 
minimum of time. If too much time is consumed in passing 
through this phase, loss of overrun may result as the cell walls 
may not be sufficiently hard to prevent the escape of the air, and 
in addition the ice cream will become coarse and grainy. 

The temperature will remain nearly constant for several min- 
utes, and then it will gradually fall until it reaches equilibrium at 
a point near the temperature of the hardening room. The heat 
absorption during this phase is in about the same proportion to 
the number of decreased degrees, as in the specific heat phase. 
The ice cream should remain at the low temperature acquired in 
this phase, until consumed. 

PROPER OVERRUN. 

It has been proved bj' experience that ice cream of proper 
composition, containing 95 to 100 per cent overrun, makes a most 
satisfactory product. This does not mean where the general aver- 
age is as above, but with some of the freezers being drawn at 60 
per cent and others at 140 per cent. The overrun upon each single 
freezer should be controlled, and every freezer drawn when the 
overrun reaches the standard set. The overrun for ice cream con- 
taining crushed fruits is usually set at about 10 per cent under the 
standard for the plain varieties. Some manufacturers prefer an 
overrun standard of as low as 70 per cent, and again others desire 
as much as 110 per cent. This is a matter to be decided by local 
conditions, trade requirements, and quality of product desired. 

The overrun in ice cream is influenced by a number of factors. 
The principal of these will be discussed in turn, indicating as far 
as possible under each factor the conditions required for obtain- 
ing the best results. 

(1). The Composition of the Mix. 

The influence of the composition of the mix is a most important 
one as affecting overrun, both in producing and in retaining the 



448 



The; Overrun in Ice Cream 



overrun after it has been obtained. A high overrun can be ob- 
tained from a mix without fat, or from one low in T. S., but in 
order to produce a product that is smooth to the taste, and one 
that will retain its overrun and give satisfaction, a fair amount of 
both fat and T. S. must be used. 

A careful experiment was made to determine the influence of 
composition upon the freeezing of ice cream. All conditions were 
the same except the composition of the mix. Several freezings 
were made from each lot of mix. The average results obtained 
are given upon the graph in Fig. 94. 




TIME IN MINUTES 



Fig-. 94. Inflvience of Composition Upon the Preezing of Ice Cream. 



Effect ok Composition on Overrun 449 

As indicated by the results upon the above graph, mix high in 
milk solids not fat and comparatively low in fat, acquired overrun 
much more rapidly than in the reverse case. The overrun is best 
controlled and the finished product is the most satisfactoj-y if the 
fat is maintained between 8 and 18 per cent and the total solids 
are maintained between 33.00 and 40.00 per cent. The extremes 
would apply only to exceptional products. Of great importance in 
its influence upon overrun is the proportions of the various consti- 
tuents that make up the total solids. Probably of first importance 
is the amount of milk solids not fat, and more especially the 
amount of casein and albumen that constitute part of the milk 
solids not fat. 

The maximum allowable percentage of milk solids not fat is 
limited to the quantity that may cause sandy ice cream, as de- 
scribed under Chapter XIII. Less than nine per cent of milk 
solids not fat will make it very difficult, if not impossible, to obtain 
any overrun that maj^ be desired in excess of 75 to 80 per cent. A 
milk solid not fat content ranging from 9 to 12.50 per cent will 
help greatly in making it possible to obtain up to 100 per cent 
overrun with comparative ease. With an ample supply of milk 
solids not fat, there is no difficulty in obtaining the desired over- 
run, regardless of what the fat content may be. The fat is, of 
course, of great importance as affecting other qualities and prop- 
erties of the ice cream. 

From 13.00 to 14.00 per cent of sugar is universally recognized 
as the most satisfactory. When less than 13.00 per cent sucrose, 
or its equivalent in SAveetening power, is used, the finished product 
is not sufficiently sweet, and using over 14.00 per cent increases 
the freezing point and makes it much more difficult both to obtain 
and to retain the overrun. 

The extent to which the sugar content influences the overrun 
is indicated under Fig. 95, which is reproduced by courtesy 
of the Telling Belle Vernon Co. 

As the results upon the chart indicate, the ability to produce 
overrun in the ice cream when freshly prepared decreased with an 
increase in the sugar content. 



450 



The Overrun in Ice Cream 




77Ai/£ /yV MINUTES 

Pig". 95. Influence of the Sugrar Content of the Mix Upon the Production of 
Overrun in Ice Cream. By W. O. Prohring-. 

Reproduced by Courtesy Telling Belle Vernon Co. 



( 2 ) . The Agingf of the Mix. 

The practice of aging the mix by holding it in storage tanks at 
a temperature of 32 to 40° F. is followed by many manufac- 
turers, but the practice is by no means a universal one. If the mix 
is properly handled, the necessary overrun can be obtained with- 
out aging, although the advantages in favor of aging are sufficient 
to warrant this practice where possible. This has been found in 
some cases to be the only method that would make it possible to 
obtain the overrun desired. Aging increases both the acidity and 
the viscosity of the mix. The acidity is due to the development 
of acid as in the case of the souring of any other dairy product, 
being caused by bacterial growth. 

The increase in acidity is very slight if the aging is done at 40° 
F. or less, and if the mix is not aged in excess of 72 hours. 

The gelatin added to the mix exerts probably more influence 
upon increasing the viscosity in aging than does the acidity devel- 
oped by bacterial growth. As shown in Chapter XIII, gelatin solu- 
tions increase greatly in viscosity upon aging at low temperatures. 
The hydration of gelatin is a slow process, and the increase in 



Aging the Mix 



451 



viscosity which accompanies hydration is favored by low temper- 
atures, such as are used when aging ice cream mix. 

The low temperatures used in aging ice cream mix no doubt 
cause a certain hardening of the constituents, particularly the fat 
and the protein, and in turn this probably exerts some influence 
upon the viscosity. 

Whatever the cause may be, it remains a well established 
fact that viscosity increases with aging, and that an increase in 
viscosity favors the incorporation of air into ice cream. 

A careful experiment by W. 0. Frohring shows the influence of 
aging upon the production of overrun, as illustrated upon the 
graph under Fig. 96. 




Fi£f. 96. The Influence of Aging Upon the Production of Overrnn in Ice Cream, 

By W. O. Prohringr. 

Reproduced by Courtesy Telling Belle Vernon Co. 



As indicated by the graph, the same mix yielded 100 per cent 
of overrun after 24 minutes in the freezer without aging, and 
after 12 minutes after aging 24 hours. 

The aging operation requires careful watching on account of 
the danger of over-ripening which causes the mix to become sour; 
and to change from a viscous to a lumpy condition, under which it 
becomes difficult to retain air in it, in the freezer. 



452 The; Overrun in Ice Cream 

Aging usually causes an increase in the bacteria count, and 
necessitates increased storage capacity. 

(3) . The Acidity of the Mix. 

The acidity is an important factor in obtaining the most desir- 
able flavor and texture in the finished product, and in controlling 
the overrun. An acidity of between .25 per cent and .30 per cent 
is considered as giving the best results. The presence of too much 
acid may cause the mix to curdle, particularly where the same is 
pasteurized. 

The acidity may be immediately increased by adding cultured 
buttermilk when compounding the mix. This will insure a good 
sharp flavor ; permit of pasteurization thus insuring a low bacteria 
count, and make it possible to produce a mix of constant and 
ample viscosity. Possibly the aging period in the case of mix 
treated in this manner can be shortened or dispensed with. This 
is a phase of the ice cream industry that is in its infancy, and it 
opens possibilities for very interesting studies. 

(4). The Viscosity of the Mix. 

This factor has already been discussed under the aging and 
acidity of the mix, inasmuch as both of the last mentioned factors 
produce viscosity in the mix. Viscosity is sometimes called the 
body or stickiness of a substance. This is a physical property that 
can be measured with great accuracy in ice cream mix by means 
of the viscosimeter described under Chapter XVII. 

The viscosity of ice cream mix is itself influenced by several 
factors. Any condition that would cause coagulation of the 
casein, or of the albumen, would cause an increase in the viscosity 
of the mix. Such conditions would be the presence of acid due 
either to aging or to the addition of pure lactic buttermilk cul- 
tures or to the addition of sucrate of lime, or the addition of some 
enzymes. Homogenizing under the proper conditions of tempera- 
ture also causes an increase in the viscosity. This factor will be 
further discussed under another heading. The matter of tem- 
perature is a very important one as affecting viscosity, inasmuch 
as this influences all the products composing the mix. The two 
best illustrations of this are the case of fat which is a liquid at 
the comparatively low temperature of 90° F. and a semi-solid at 



Homogenizing the Mix 



453 



about 60" F., and sug:ar s.yrups, whose viscosity increases so rapid- 
ly with lowering temperatures. 

As already pointed out both in this chapter and in Chapter 
XIII, one of the principal factors affecting viscosity is the gelatin 
added to the mix. 

The viscosity and the acidity of ice cream mixes of different 
compositions at different temperatures and at different ages are 
given in Chapter XIII. 




Fig". 9t, Mauton-Gaulin Homog'enizer. 

Courtesy Creamery Package Mfg. Co. 

Viscosity in ice cream mix can be readily destroyed by agita- 
tion both at low and at high temperatures. The possibility of de- 
stroying viscosity is especially favored under the violent agitation 
prevailing in an ice cream freezer. This proves the importance of 
reaching the whipping point in the freezer before the viscosity 
of the mix has been reduced. If brine of too high a temperature 
or of insufficient volume is used, the viscosity may become suffi- 
ciently reduced before the whipping point is reached to make it 
impossible to obtain the desired overrun. 

( 5 ) . Homogenizing the Mix. 

The practice of homogenizing the mix is well nigh universally 
understood by ice cream manufacturers, and the importance of 



454 The Overrun in Ice Cream 

this operation is being increasingly appreciated. Machines upon 
the market for performing this operation are known both as 
homogenizers and viscolizers. These are made in such a large 
range of sizes (60 gallons to 800 gallons per hour capacity) as to 
be within the reach of both small and large manufacturers. 




Fig". 98. Progress Homog°enizer. 

Courtesy Davis-Watkins Dairymens Mfg. Co. 



As the term implies, homogenizing the mix makes a product 
that is uniform throughout its mass, in its physical properties. 
The large fat globules are broken up into smaller ones, and like- 
wise particles of the other constituents are all reduced to small 
dimensions. This result is reflected in the finished product, the 
latter being of smoother texture than where the mix is not homo- 
genized. The three other most important results obtained from 
homogenizing are (1) the ability to produce ice cream of the de- 
sired overrun under nearly all conditions of operation ; (2) the 
production of ice cream that retains its overrun better when once 
obtained, and (3) decreased danger of churning the fat in the 
freezers. 

The homogenizer further makes it possible for the manufac- 
turer to use many products that could not be otherAvise employed 
for making ice cream. The' most important of these are butter 



HOMOGRNIZING THE MiX 455 

and skimmed milk powder, which can be reconstituted into milk 
or cream or condensed milk or directly into ice cream mix itself. 

The best temperature at which to homogenize ice cream mix is 
generally accepted as being 140 to 145^ P. This is considered 
the best practice from a bacteriological point of view, and also as 
pointed out by Morse", mix homogenized at this temperature does 
not become pasty, nor does it so easily acquire excessive viscosity. 




Fig". 99. Viscolizer. 

Courtesy Union Steam Pump Co. 



According to Hanna", "the age, condition and temperature 
of run entirely governs the pressure the machine should be oper- 
ated at." Pressures of 2000 to 8000 pounds give all the viscosity 
usually required, and produce a homogenous product from which 
the fat is not likely to separate under any of the usual methods 
used in freezing ice cream. 

The use of too low temperatures and of too high pressure will 
increase the viscosity too much, and in turn this may result in too 
high overrun. If under the above conditions of operation the mix 
is too low viscosity, it is an indication that the homogenizer 
is functioning improperly, and the same should be immedately 
repaired. The temperature and pressure to use are governed 
largely by result desired. 



456 The Overrun in Ice Cream 

The increase in viscosity is frequently accompanied by a large 
increase in the volume of the mix. This increase may amount to 
as much as 75 per cent of the total overrun desired. This con- 
dition should be carefully taken into consideration, as otherwise 
misleading results will be obtained in the overrun. 

(6). Amount of Mix Drawn in the Freezer. 

The volume of mix drawn into the freezer is governed in a 
large measure by the overrun desired. If 100 per cent overrun is 
desired, a 40-quart freezer should not receive more than 20 quarts 
of mix. A little less than this amount is better, since space must 
be allowed for the dasher. The same proportion would govern in 
the case of freezers of larger capacity. 

When too much mix is used, it becomes necessary to draw out 
some of the ice cream before the full overrun has been obtained. 
This necessarily causes a product of uneven overrun. 

This factor can be closely controlled by fitting the supply tank 
over each freezer with an overflow pipe so adjusted that a uniform 
volume of mix will be fed into each freezer, or with a batch 
weigher. 

(7). Type of Freezer. 

The design and the mechanical construction of the freezer are 
important factors as affecting overrun. Repeated experiments 
have shown that it is much more difficult to obtain the desired 
overrun with freezers of the vertical type as against those of the 
horizontal type. In some cases it was found to be impossible to 
increase the overrun in certain vertical freezers beyond 70 per 
cent with all other conditions under control. 

The blades of the freezer should be kept sharp and adjusted 
so that they scrape evenly against the side of the freezer. If this 
is neglected a coating forms on the inner wall of the freezer and 
tends to slow down the freezing operation by preventing the heat 
in the mix from passing into the brine. 

Another source of trouble traceable to the freezer is due to the 
slipping of the belt, thus causing improper dasher speed. On 
account of the damp conditions that obtain in the average freezing 
rooms, freezers that are equipped with direct motor drive are 
the most likely to prove satisfactory. 



Brine Temperature and Pressure 457 

(8). Brine Temperature and Brine Pressure. 

An important relation exists between the brine pressure and 
the brine temperature. The matter of temperature is more impor- 
tant than that of pressure, the controlling principle being the 
necessity of having a sufficient volume of brine to insure maintain- 
ing the proper temperature inside the freezer. This can be ascer- 
tained by noting the ditiference in the temperature between the in- 
coming and the out-going brine, which should be about 5° F. 

The brine pressure determines the volume going through the 
freezer. The pressure and the volume are in turn both influenced 
by a number of factors, such as size of the brine pump and of the 
brine pipes ; the number of angles in the pipe lines, and the dis- 
tance that the brine has to travel between the brine pump and the 
freezer. Obviously when the above conditions are favorable, the 
brine pressure may be much lower than when the opposite condi- 
tions prevail, 

Washburn^ recommends the following relation between 
those two factors: "For a temperature of 12- F., use a pressure 
of 10 pounds; for 10' F.. use 9 pounds, and for 8^ F. brine use 
about 7 pounds." Upon the other hand, some very successful 
manufacturers, using S'' brine operate under a pressure of 45 
pounds. The important consideration is to so corelate the brine 
temperatures and brine pressure, so as to obtain the desired over- 
run i]i the required time, under the varied conditions that prevail 
in ice cream plants. 

When the temperature of the brine is below zero it is difficult 
to get good results. The temperature 'of the brine should be such 
that when about 100 per cent of overrun has been obtained, with 
the brine turned off, the overrun will decrease rapidly upon turn- 
ing on the brine again. If turning on the brine, after the desired 
overrun is obtained with the brine off, does not reduce the over- 
run, it is an indication of improper brine temperature, or of insuf- 
ficient brine flowing through the freezer. In such a case it is ad- 
visable to stop the operation of the freezer until the brine temper- 
ature can be reduced to such a point that the freezing can be done 
efficiently and the overrun can be properly controlled. A brine 
temperature of 8 to 12" F. is universally recognized as the 
most desirable brine temperature to use, although the present 



458 The Overrun in Ice Cream 

tendency is to use even lower temperatures than these. Other 
conditions being right, the lower the brine temperature, the 
greater the output that can be obtained from a given number of 
freezers 

When using brine of too high a temperature, there is great 
danger of churning out the fat in the mix before the whipping 
temperature is reached. This is especially true if the mix is of a 
fairly high temperature Avhen the same is introduced into the 
freezer. Churning may also be caused by insufficient brine, thus 
prolonging too much the time required to reach the whipping 
temperature. 

It is important to equip both the brine inlet and outlet upon 
each freezer Avith thermometers, in order to observe the temper- 
ature of the incoming and outgoing brine. 

A leaky valve may be the cause of low overrun due to im- 
proper brine circulation. These should, therefore, be in good con- 
dition, so that when they are turned oft' there will be no leakage 
of brine through the freezer. 

When several freezers are operating in a row, all of which 
receive their brine from a common pipe, it is of great importance 
to so arrange the piping that each freezer in the row will receive 
the same amount of brine. 

(9). The Speed of Freezer; Time Given to Freezing; Temper- 
ture of Incoming Mix and Outgoing Ice Cream. 

All of the above factors are so closely correlated as to merit 
discussion together. 

The proper speed of dasher varies with the size and make of 
the freezer. Experience has proved as a rule that, with the brine 
temperature of about 12^ F., the best results are obtained where a 
dasher speed of 200 revolutions per minute is used. The colder 
the brine the faster the dasher should operate, on account of the 
shorter time required for freezing. Therefore, in order to obtain 
the desired overrun, it is necessary to operate the dashers fast 
enough to incorporate in the mix the same volume of air in the 
shorter time that would be incorporated into it in the longer time 
with a lower brine temperature. Washburn states, "If 6 minutes 
be required with a dasher speed of 225 turns per minute, this will 



Factors Affecting Freezing 



459 



make a total of 1350 turns, during the given period. Whereas, if 
the brine is too cool, or flows too rapidly, and the freezing period 
is passed through in say 4 minutes, there will necessarily be only 
900 turns during this period, and there will be considerably less 
swell than if the full 1350 turns had been given." 

The time given to the freezing will be governed by the brine 
temperature, the temperature of the incoming mix and the dasher 
speed. 

The correlation of these several factors is indicated in Table 92. 

TABLE 92. 

Correlation Dasher Speed, Temperatures Incoming Brine and Mix, and Time 

Required to Freeze. 



Dasher speed 
revolutions 
per minute. 


Temperature 

incoming brine 

degrees F. 


Temperature 

incoming mix 

degrees F. 


Minutes required 

to freeze the 

batch. 


250 





33 


6 


240 


6 


32 


8 


230 


6 


38 


10 


230 


12 


32 


12 


225 


12 


32 


12 


200 


18 


38 


18 


165 


8 


40 


12 



The practice of holding the mix at 32 to 35° F. and freez- 
ing in from 6 to 8 minutes usually results in the formation of 
grainy ice cream unless the dasher speed be greatly increased. 
It is generally conceded that the best results are obtained under 
the following conditions : 

Speed of dasher, 225 revolutions per minute. 

Temperature of incoming brine, 8° F. 

Brine pressure, 11 pounds. 

Temperature incoming mix, 32 to 36° F. 

Minutes required to freeze batch, 12 to 15. 

The temperature of the outgoing ice cream, or in other words 
the freezing point of the mix, depends upon its composition and 
especially upon its content of both milk and cane sugar. The 
sugar content exerts the most influence upon the freezing point. 



460 The Overrun in Ice CrEam 



• . 



A mix with too low a freezing point is not only more difficult 
to freeze, but the danger from subsequent loss of overrun is corre- 
spondingly increased. This is obvious from the fact that the 
lower the freezing point, the more difficult it becomes to maintain 
in the holding cabinets the lower temperatures required to keep 
the product frozen. 

HOW TO RETAIN OVERRUN AFTER THE ICE CREAM LEAVES 
THE FREEZER. 

It is one thing to manufacture ice cream with the desired over- 
run. It is another thing to retain the overrun in the ice cream 
between the time it leaves the freezer until consumed. Com- 
plaints of shrinkage are quite numerous, and causes for such 
shrinkage are not always under proper control. The principal 
factors causing loss in overrun are as follows : 

(1). Improper Composition of Mix. 

The use of too much sugar as already pointed out, lowers the 
freezing point of the mix. On account of the difficulty of main- 
taining abnormally low temperatures in ice cream cabinets, loss 
in overrun results unless the required temperatures can be main- 
tained. Proper control over the composition of the mix will pre- 
vent trouble from the above cause. 

(2). Too High Temperature in Hardening Room. 

The temperature of the ice cream as it leaves the freezer is 
usually from 26 to 28'' F. If kept at this temperature longer 
than one or two hours, the air will gradually escape. It is there- 
fore necessary to harden the ice cream immediately, and the tem- 
perature found to be the best to maintain in the hardening room 
is 0° F. It is difficult to control properly with one compressor, 
the above low temperature for the hardening room, and the 
higher temperature of about 12° F. required at the freezers. 
Where ammonia compressors are used, with the ammonia enter- 
ing the compressor at 0° F. the low pressure gauge will register 
about 16 pounds. This is the condition required for the most 
satisfactory work at the freezers while for hardening room work 
the incoming ammonia temperature should be about — 20° F. 
which will make a gauge pressure of about 4 pounds per square 



PuLiviNG THE Freezer 461 

inch. For these reasons the most satisfactory results are obtained 
where this may be possible by using a separate compressor for 
each operation. 

HalP recommends the use of one hardening room of about 
— 15° F. which is to be used for hardening the ice cream im- 
mediately after it leaves the freezers. After the ice cream has 
hardened he recommends transferring it into the regular harden- 
ing room with temperature around 0^ F. Under this condition of 
handling the ice cream will have smaller water crystals, and 
therefore it will be smoother to the taste. 

(3). Drawing- the Ice Cream From the Freezer While Too 
Soft or at Too High a Temperature. 

If the overrun is obtained too early during the freezing 
period, the viscosity is not sufficient, or in other words the walls 
of the cells are not strong enough to retain the enclosed air. 
Such ice cream is also almost certain to melt slightly against the 
side of the cans and later on when hardening, the melted portion 
will form coarse ice crystals. Under a condition of this kind 
even if the hardening room has the proper temperature, loss of 
overrun is very likely to result. The shrinkage is likely to be 
greater if air hardened, than if hardened in brine, owing to the 
quicker cooling by the latter method. 

The following experiment was made by W. 0. Frohring of the 
Telling Belle Vernon Co., and the results are reported with their 
permission. 

"Out of the same freezer, one can was drawn in the early part 
of the freezing period with the overrun at 70 per cent. Another 
can was drawn near the end of the freezing period with an over- 
run of 120 per cent when the temperature had about reached 
the critical point. Both cans were placed in the hardening room 
under a temperature of about 0° F. The following morning the 
can with 70 per cent overrun had suffered great loss in overrun 
while that with 120 per cent overrun, had suffered no loss in 
overrun and the same was normal in all respects." 

The above trouble can be entirely prevented by continuing the 
freezing operation until an overrun is obtained slightly in excess 
of the standard desired, and then by momentarily turning on the 



462 Thii; Overrun ik Ice Cream 

brine again, beat back the overrun to the point desired. Or it 
can be avoided by closely controlling all factors involved, and 
drawing the ice cream as soon as the desired overrun is obtained. 
This is the better method. 

Washburn further points to the importance of precooling the 
empty cans before running the ice cream into the same. 

(4). Too High Overrun. 

The presence of too much overrun is frequently attributed 
as being the cause of loss of overrun. Overrun in excess of 100 
per cent is seldom if ever desirable, and such excessive overrun 
may be responsible for many ice cream defects, and should be 
guarded against. No doubt the presence of too much overrun 
can aggravate shrinkage troubles, but it is not necessarily in 
itself the cause of such troubles. 

(5). The Relation of Gelatin to Overrun. 

The value of gelatin in helping to obtain overrun in ice cream 
is practically universally recognized. Its value in helping to re- 
tain the overrun has not been so clearly demonstrated. The 
quantities of gelatin ordinarily used, are too limited to exert any 
appreciable effect upon the ability of the ice cream to stand up 
after freezing. 

The two principal physical properties of ice cream are its 
body and its texture. By body is meant the viscosity — that is, 
if the product is soft, mellow or hard. By texture is meant the 
smoothness to the taste of the ice cream. The body is influenced 
largely b}'' temperature, composition, and the processes of manu- 
facture used. The favorable influence of gelatin upon the texture 
of ice cream is now universally conceded. This influence be- 
comes more marked after the ice cream has passed 24 to 48 hours 
of age. This svibject is further discussed in Chapter XIII. 

Most of the above factors can be kept under the control of the 
manufacturer provided the plant is equipped with the neces- 
sary apparatus for making the tests required. However, condi- 
tions sometimes arise under which it is impossible to obtain the 
desired overrun. The cause for such conditions requires close 
investigation. 



The MojoNNiER Overrun Tester 463 

THE MOJONNIER ICE CREAM OVERRUN TESTER. 

The fundamental principles that control the percentage of 
overrun in ice cream are not always well understood by those 
in charge of the ice cream freezers. In fact, it is only in very 
recent years that problems connected with the process of con- 
trolling the percentage of overrun have received serious atten- 
tion. Furthermore the use of modern machinery, a variety of 
new raw materials, with new methods of manufacture have in- 
troduced new factors, affecting overrun, not previously encount- 
ered. 

To J. J. Mojonnier belongs the credit for the invention of the 
Mojonnier Ice Cream Overrun Tester illustrated under Fig. 
100. Patents both pending and obtained in his name cover both 
the process used, and the mechanical devices for applying the 
process. The test is based upon the difference in weight between 
equal volumes of ice cream mix and the frozen product. 

Tlie great advantage in the use of the Mojonnier Overrun 
Tester is that it enables the ice cream maker to make a nearly 
instantaneous test for the percentage of overrun, at any time 
during the freezing operation. This enables the operator to 
change the freezing process so that as a rule any desired per- 
centage of overrun may be finally and readily obtained. 

The Mojonnier Ice Cream Overrun Tester has been proved to 
be absolutely accurate both in principle and in practice. A single 
test for overrun can be made in about five seconds, and the num- 
ber of tests that can be made is limited only by this time require- 
ment. It is easy and convenient to operate and can be applied by 
any one who can read figures. No chemicals or glassware are 
needed in making the tests. 

TWO METHODS FOR APPLYING THE MOJONNIER ICE CREAM 
OVERRUN TESTER. 

First Method : In plants operating less than four, or mul- 
tiples of four freezers, the tests for overrun are made to the best 
advantage by the freezer operator. It is recommended that the 
Mojonnier Overrun Tester be located between the freezers as in- 



464 



The Ovp:rrun in Ice CrEam 



dicated in Fig. 100. It is designed to be used from both sides. 

Under this arrangement the freezer operator can make the 
tests and control the overrun upon four freezers, which works out 
very well in practice. 

Second Method: In, plants operating more than eight freezers 
a special operator, usually a bright girl can be employed to make 
overrun tests only, using one operator for each lot of six freezers. 
The Tester operator instructs the helper to draw off the ice cream 
after the desired overrun has been obtained. This method gives 
good results in large plants. 




Figf. 100, Sug"g"ested Location of Mojonnier Overrun Testers in the 
Preezer Boom. 



DIRECTIONS FOR SETTING UP THE MOJONNIER OVERRUN 

TESTER. 

It is very important for intending operators to read these 
directions carefully before attempting to set up and operate the 
Mojonnier Overrun Tester. The directions should be kept con- 
veniently at hand and be referred to from time to time, even 
though the user is quite familiar with the operation and care of 
the machine. After the Tester is properl.y installed and adjusted, 
the operation of the same is very simple. 



Location of Tester 465 

Uncrating. When uncrating the tester use extra precaution 
so as not to injure the delicate working parts of the scale, or the 
white finish. 

Accessories : Packed in the case accompanying the Overrun 
Tester the following accessories should be found. 

Quantity 
Aluminum screw base cups with hollow counterpoised handles 2 

Broad nickel-plated scraper knives 2 

100% Counterpoise 1 

0%. Counterpoise 1 

Spouted dipper for pouring in mix 1 

Key for locking door to pedestal cabinet 1 

Small bottle of shot for counterpoising cups 1 

6 Ft. Electric light extension cord plug and socket 1 

110 volt electric light bulbs for lighting scale dial inside of 

cabinet 2 

Bottle of refined dash pot oil 1 

Small metal trough for pouring oil into the dash pot 1 

Pad of freezer room reports 1 

Clip for holding freezer room reports 1 

Binder for freezer room reports 1 

Leveling- and fastening in Position. Level the base or pedes- 
tal carefully as follows : 

Place the slotted base of the empty overrun cup over the metal 
cleat on the horizontal surface just above the pedestal cabinet. 
Fill the cup to overflowing with water. Scrape off the water 
Avith a scraper knife to an even level, and use the filled cup as 
a level to accurately level the pedestal base on the floor. This 
will insure absolute accuracy when the cup is adjusted for the 
mix. When the pedestal is leveled, fasten with lag screws or 
bolts to the floor, using the same method as is used in fastening 
the base of freezers to the floor. 

Adjusting the Scale. Unscrew the oblong plate upon the side 
of the scale cabinet which will allow access to the scale, electric 
light sockets and the scale level. The scale beam is held rigid 
for shipping with a U-shaped wire encircling it about in the 
center, and a rod to the right of the beam. Pull both of these out. 
See Fig. 101. 



466 



The Overrun in Ice Cream 



Level the scale as shown in Fig. 102 by turning the adjusting 
screw in the rear of the Overrnn Tester. This can be done by 
watching the level in the base of the scale itself. 








''^^IJliMiE''' 


, 






li' -^-"WH 


B' 


^ WF .m^^i 


i% %£r:^lM 


K 


\:^ 


]*-"7l 


^ ■ 'm 


^iil 



rig-. 102. Iieveling- Scale. 




Pig". 101. Removing- Wire 

and Sod from Scale Beam. 

This allows the scale beam 

to move freely. 



Pig-. 103. Pilling- Dash Pot With Oil. 



Filling and Adjusting the Dash Pot. 

Remove the screws holding the rectangular glass plate upon 
the scale, permitting access to the scale dash pot. Unscrew the 



RE:Gm..\TiNc. Vibration 



467 



dash pot cap and fill the pot with oil by means of small metal 
trough furnished. See Fig. 103. Pour oil in the dash pot to the 
BASE LINE shown in Fig. 104 or about two-thirds full. When 

replacing cap, be careful to avoid cross- 
ing the threads. The dash pot construc- 
tion makes the scale very sensitive and 
eliminates excessive -vibration of dial 
indicator. 

Note : Use in dash pot only such oil 
as is furnished by the manufacturers as 
this is a high grade refined oil, and is 
of the proper consistency for this work. 
A — Clevis pin. B — Vibration regulat- 
ing screw. C — Dash pot cap. D — 
Dash pot plunger. E — Plunger cap. 

Regulating Vibration of Dial Indi- 
cator. 

Place the empty overrun cup on 
horse shoe shaped, suspended weighing 
frame. Place 100 per cent weight on 
form immediately above the cup. The 
indicator should point to 100 per cent 
on dial. If indicator points to 96, un- 
rig-. 104. Dash Pot in Cross screw the Cap in the cup handle and 
Section. ^^jjg ^^^ gj^^^ ^j^^Q ^j^g indicator points 

to 100. If over 100 add necessary shot. 

Take off 100 per cent weight and put on per cent weight, 
and proceed in the same manner. 

If the pointer moves too freely or too slowly, or "jiggles", 
turn the thumb screw B shown in Fig. 104 either to the right or 
to the left, which adjusts the two discs on the dash pot plunger. 
By means of this vibration regulating screw, the pointer can be 




468 



The Overrun in Ice Cream 




Tig. 105. Adjusting Movement 
Pointer By XHeans of Screw B. 



of 



regulated to a nicety, so that 
it will go to its maximum 
point quickly, and remain 
there with practically no vi- 
bration. See Fig. 105. Be 
sure however, not to get the 
vibration screw too tight, as 
the action of the plunger may 
thus be retarded and result in 
incorrect readings. 

When it becomes impos- 
sible to regulate the vibration 
in the manner described 
above, it indicates that it is 
necessary to refill the dash 
pot with oil. When properly 
adjusted the scale is sensitive to one gram, or about one-twenty- 
eighth of an ounce. Unnecessary changing or regulating of 
the scale parts should be avoided. Should there be any trouble 
in carrying out the above instructions the manufacturers should 
be notified so that further instructions can be furnished. 

When the adjustments are completed replace the glass plate 
on the scale, and the oblong metal plate on the scale cabinet. The 
Mojonnier Overrun Tester is then ready to operate. 

Adjusting Pointer of Automatic Scale. 

In shipping, the adjustment of the automatic scale is some- 
times jarred loose, and the pointer then registers inaccurately. 
If the scale is made to register correctly with the per cent 
weight in place, and then tlie 100 per cent weight is substituted, 
the pointer sometimes indicates either more or less than 100 per 
cent. 

To make the necessary adjustment, first place the cup and the 
per cent weight on the hanger, and add to, or take lead from 
"C" until the pointer registers exactly per cent. Next, substi- 
tute the 100 per cent weight for the per cent weight, and note 
exactly what is registered on the dial. 



Overrun Cup 



469 




Eemove plate "A" aud take out the screw in the end of pen- 
dulum "B". Attached to the screw will be found lead weights. 
If less than 100 per cent is registered on the dial, remove about 
.1 gram of lead for each point short. If more than 100 per cent 
add about .1 gram for each point over, and replace the screw in 
the pendulum. Put on the per cent weight and add to, or 
remove lead from "C" until the pointer registers per cent 

again. When the 100 per cent weight 
is again substituted, the pointer 
should indicate 100 per cent. If still 
slightly over or under, the 
c adjustment should be re- 

peated, taking off or adding 
a very small quantity of lead. 

The Overrun Cup. 

The Overrun Cup is fitted 
with a telescopic bottom, and 
it should be adjusted for 
every batch, except in ice 
cream plants that carefully 
standardize the percentage of fat and total solids, in the 
mix. In such instances, after the cup has been once adjusted, 
it will require very little, if any adjusting thereafter. For in- 
stance, if the mix is standardized to 8 per cent fat and 34 per cent 
total solids, and kept at this standard by careful testing, no 
further adjustments of the overrun cup need be made thereafter. 
In all plants where the mix is standardized an overrun cup can 
be used, the body of which is made in one piece. In plants where 
more than one quality of ice cream mixes are made and standard- 
ized, overrun cups with solid bodies can be supplied for each 
quality of mix. This will simplify the problem, and help to pre- 
vent errors. Reference to Table 44, Chapter XIII, will show 
that at equal temperatures the weight of unit volumes of 
ice cream mix of comparatively wide differences in composition, 
varies relatively but little. Ice cream mix testing 8.00 per cent 
fat and 33.00 per cent total solids, at 40° F. weighs 9.19 pounds 
per U. S. gallon. Ice cream mix testing 18.00 per cent and 40.00 
per cent total solids at 40° F. weighs 9.04 pounds per gallon. The 



Pig-. 106. Phantom View of Scale Show- 
ing- "Where to Make Pointer Adjust- 
ments. 



470 



The Overrun in Ice Cream 



diffei'eiice is onl.y .15 pounds per gallon or a possible error of 1.66 
per cent upon the frozen ice cream. 

Daily Care to Give to Overrun Tester. 

Each day before freezing the overrun cup should be checked 
against the per cent counterpoise and the 100 per cent counter- 
poise to insure accuracy of test. 
The hollow handled construction of 
tlie cup will permit adding to or 
taking from the cup, the shot used 
in counterpoising. After the freez- 
ing is finished it is absolutely neces- 
sary that the overrun cups have the 
following attention every night : 

(1). Clean and dry the cups 
thoroughly. 

(2). Remove the telescopic 
base where this type of overrun cup 
is used and thoroughly smear all 
threads and screw connections with 
vaseline or oil. 

Unless the above rules are care- 
fully observed the j^crew base of 
tlie cup will become corroded and 
may "stick," making it very diffi- 
cult to adjust. 

Adjusting- the Overrun Cup 
Against the Mix. 

Pig-. 107. Adjusting- the Overrun Carefully study and carry out 
cup for any Composition of' Mix. ^j^j^ operation. The overrun cup is 

Remove the Cup of Mix from the ^ 

Scale, and Place the Slotted Base first balanced against the per cent 

on the Metal Cleat Under Weigrh- ,^,^,i i^^ Tj^^ tclcSCOpic baSC of the 
ing- Prame. ^ -^ 

overrun cup is unscrewed as far as 
is necessary to hold 500 grams of the mix. This will amount to a 
little more than one pint. Place the empty overrun cup in the 
suspended cup holder. Fill the dipper with the finished mix from 




i 



Adjustinc. the Cup 



471 



the aging tank and pour the mix into the cup until the dial in- 
dicator points to per cent. See Pig. 107. The mix at this time 
should contain all of the ingredients that enter into the frozen 
product. As already pointed out, there is ahvays a possibility of 
a certain amount of air becoming incorporated with the mix 
during the process of homogenizing. It is of the utmost im- 
portance when adjusting the overrun cup, to make the adjust- 
ment upon the basis of a mix that is free from air. 




Fig. 



108 . Emptying- Overrun Cup 
Into Freezer Hopper. 



Tij. 



109. Adjusting- Telescopic Bot- 
tom Upon Overrun Cup. 



Where to Get the Sample of Mix for Adjusting the Overrun 
cup. 

It is of great importance to obtain the sample of mix from the 
holding tank, before any air has been incorporated into the mix. 
If the sample should be obtained after air has been whipped into 
it, and the overrun cup adjusted upon the basis of such a sample, 
the overrun consequently obtained will not represent the true 
overrun, and there may be great danger under such a condition 
of producing ice cream with excessive overrun. 



472 



The Overrun in Ice Cream 



Adjust the telescopic base by turning the cup around so that 
the top of the mix comes exactly even with the top of the cup. 
Carefully lock the base of the cup tight by means of the knurled 
locking ring. 

Empty the mix back into the hopper over the freezer, see 
Fig. 108. and rinse out the cup in a pail or five gallon can of 
tepid water, making ready for the overrun determination. 

There is now a fixed relation between the capacity, and the 
weight of the cup, a]id the markings on the scale dial. The dial 
will indicate the percentage of overrun nearly instantaneously 
when the cui), filled with ice cream, is placed upon the suspended 

weighing frame. 




rigr. 110. rillingr overrun Cup With Ice 
Cream at the Freezer. 



Finding the Exact Per 
Cent of Overrun. 

DraAv a heaping cup of 
tlie frozen ice cream from the 
freezer, using the broad 
plated knife scrape off the 
excess to an even level with 
the top of the cup. See Figs. 
110 and 111. Place the cup 
in the suspended cup holder. 
The dial indicator will im- 
mediately show the percent- 
age of overrun. If it points 
to 60, it indicates 60 per cent 
of overrun. If to 90, it in- 
dicates 90 per cent overrun, 
etc. Two operators may use 
the same Overrun Tester at 
the same time if desired, one 
operating from either side. 
Eepeated use of the Over- 
run Tester will enable the 
operator to handle the Avork 
with dexterity and speed. 



Standardizing the Overrun 



473 



<9 




► 



Pig-. 111. Scraping- Overrun 
Cup Iievel Full of Ice Creani. 




Pig-. 112. 



Making- Reading- for 
Overrun. 



HOW TO STANDARDIZE THE OVERRUN. 

In standardizing the overrun, the Mojonnier Overrun Tester 
should be used on every freezer of ice cream drawn. As it takes 
only five seconds to make the test there is no good reason why 
this important part of the work should be omitted. 

First operation : When starting to freeze a new batch, see 
that the overrun cup is adjusted as described on page 470. 

Second operation : Draw not more than five gallons of mix 
into the hopper above the freezer when using a ten gallon freezer. 
If larger freezers are used, draw a volume into the hopper equal, 
but not to exceed, one-half the rated capacity of the freezer. 



474 



The: Overrun in Ice: Cre:am 



Third operation : Run the rnix into the freezers as usual, fill- 
ing all freezers while the}^ are running. 

Fourth operation : Turn on the brine and continue whipping. 

Fifth operation : Watch the ice cream through the freezer 
peep hole in front of the freezer during the time of freezing and 
whipping, and as soon as it becomes sufficiently viscous, make a 
test for the overrun. This will be when the overrun is between 
60 to 80 per cent. 



Plul 

T«t made by. 



FREEZING ROOM REPORT 



1 


OIUO. 


T„,| - 


Tow pouDd. n» 






























..... 










o„.™. ...1 








..... «... .«!. 










„. ..». 


■....• — 


>„.....». 1 I, 














j 








N. 1 


1... 


«.. 


».. 




"i.if.r' 


"i.lif 


"ii-S" 


"ijja 1 'iisf 














-— 




































— 









































- - 




























































- 






' — 
























- 












^...s 


































- 





















-- 

































-- 






















































































: 






























'IZ'Il 




- ■ - 




":z: 








- 





:zz 




























— 





























Tig. 113. Blank for Recordinif Overrun Beadingfs, 



Sixth operation : If aiming for 100 per cent overrun and the 
test shoAvs between 95 and 100 per cent, turn ofif: the brine and 
draw the freezer. Where the overrun is more than 110 per cent, 
the product is usually unsatisfactory, and the overrun should be 
brought back to the point desired, by momentarily turning on the 
brine. If the test shows less than 95 per cent turn off the brine 
and continue whipping until the desired percentage of overrun 
is obtained. The frozen ice cream should be sufficiently viscous 
to retain all of its overrun during the hardening process. 

Seventh operation: At this i)oint draw the ice cream into 
the cans, and record the percentage of overrun in the proper 



i 



Overrun in Fruit Ice; Cream 475 

column of the freezing room record sheet, illustrated under 
Fig 113. 

Ice cream of ideal texture will have the appearance of taify 
when it is frozen, and ready to be drawn from the freezer. If of 
the proper texture it will stand considerable handling, without 
suffering an^^ bad effects. 

The ice cream should be drawn from the freezer as rapidly 
as possible, inasmuch as the overrun keeps changing upon the 
part that remains in the freezer while the balance is being drawn 
out. The change may occur in both directions. If the critical 
phase has not been reached, the overrun will increase, making the 
last portion of higher overrun than the first portion. If the criti- 
cal phase has been passed, the overrun Avill decrease, making the 
last portion of lower overrun than the first portion. If the ice 
cream is drawn rapidly the danger from these fluctuations can be 
great!}' reduced. Proper manipulation of the brine valve may 
frequently assist in preventing the above changes. 

It is important to draw off the ice cream as rapidly as possible 
when the proper overrun is reached, so that the overrun does not 
increase during the time of drawing off. A helper may be used 
to advantage at this time to bring in empty cans, and take away 
filled cans. 

HOW TO DETERMINE OVERRUN IN ICE CREAM CONTAINING 
CRUSHED FRUITS. 

It is recommended that a different standard be set for ice 
cream containing crushed fruit, than for the plain varieties. For 
example if the standard for plain variety is 100 per cent, a stand- 
ard of 90 per cent in the case of ice cream containing crushed 
fruit will yield a very satisfactory product. 

REFERENCES. 

1 Washburn, R. M. "Principles of Ice Cream Making," Vermont Station 
BuUetin No. 155. 

- Baer, A. C. "Ice Cream Making," Wisconsin Station BuUetin No. 262. 

3 Mortensen, M. Factors which influence the yield and consistency oJ 
Ice Cream. Iowa Station Bulletin No. 180. 

* Hammer, B. M. and Johnson, A. R. The Specific Heat of Milk and Milk 
Derivatives. Iowa Station, Research Bulletin No. 14. 

5 Cutler, Thos. H. Ice Cream Trade Journal, 1920. 

Morse, James B. Homogenizing the entire mix. Ice Cream Trade 
Journal, 1920. 

' Hanna, E. C. The Viscolizer is an important factor in the ice cream 
industry. Ice Cream Review, 1921. 

» Hall, Thos. Microscopic and Thermal Analysis of Ice Cream, P. 71, Ice 
Cream Trade Journal, December, 1921. 



CHAPTER XVI 

MICROSCOPICAL AND BACTERIOLOGICAL 

TESTS OF DAIRY PRODUCTS WITH 

DIRECTIONS FOR THE CARE 

AND USE OF CULTURES 

THE USE OF THE MICROSCOPE IN THE DAIRY INDUSTRY. 

Th^ microscope is used to great advantage in dairy control 
work. It is indispensable in identifying bacteria, and it fre 
quently affords a rapid means of determining the physical con- 
dition of milk substances that would require a large amount of 
time and labor to determine by other methods, or would be al- 
together impossible. The quality of milk is fixed to a large de- 
gree by the number and kind of bacteria that it contains. Also 
the physical condition of some of the constituents of dairy prod- 
ucts influences the process of manufacture, the treatment they 
must receive, and their market value. 

The successful use of the microscope in determining these 
factors does not always require the services of a highly trained 
individual. Any resourceful, intelligent young man or woman 
of limited training can determine the number of bacteria in milk, 
the size of fat globules, and the presence of milk sugar crystals, 
when provided with necessary equipment, some instructions at the 
beginning, and the directions given in this chapter. 

These brief directions should enable any skillful person to 
use the microscope successfully in the simpler operations. If 
the instrument is to be used to a large degree it Avould be advis- 
able for the operator to obtain special training, and to consult 
books devoted especially to the subject. 

Care: Some knowledge of the microscope on the part of the 
operator is necessary in order to work to advantage, and to keep 
the instrument in good condition. Like all instruments of pre- 
cision, it should be handled Avith reasonable care, and kept free 

• [476] 



The Microscope: 



477 



of dust and all corroding elements. When the instrument is not 
in use it should be kept in a case, and stored in a reasonably dry 
place. If frequent use makes it impractical to return the in- 
strument to its case, a suitable cover should be placed over it 
when not in use to protect it from dust. The frequent removal 
of dust from its polished surfaces is liable to scratch them, and 
if the dust gets into the bearings and close fittings, they will work 
harder and cause unnecessary wear. 



■Rack & BniCN 
CoARse AoJuaTweNT 



NosEPiecE 



Objectives 




Grasuatcc Short SLic t — — 

flevOLVING 

Stage 

floJUSTABLE 

Spring Finger 

CoNDENSEI^ MoUNTmS 

Drop •5wing Arm—" 
Lower Iris Diaphragm -- 
roR OeuftuE Light. 

Stage CkNTCRiNG •Screw.s'^ 

Mirror 

lVliRRO*\ roR«>-. 
MiRftOR Bar 
T?ACK & PmiON 

£yTTOH 



Concentric Altutt- 
ng Buttons 

Grabuated Long 
L5lh>e 



Horseshoe 
.— -Bas e 



Tig, 114. Microscope with ITames of Various Farts. 

Courtesy Spencer Lens Company. 



Do not leave the microscope exposed to direct sunlight for 
a long time. Avoid rough handling of the instrument and when 
it must be removed, grasp the pillar below the stage. The oculars 



478 Bacteriologicai, Tests and Cultures 

and objectives should never be allowed to fall. Do not allow 
acids, alkalies, alcohol, turpentine or chloroform to come in con- 
tact with any part of the microscope, as they will dissolve the 
lacquer. For finger marks or material on the surface, that can- 
not be removed with a soft cloth or clean chamois skin, use a 
damp cloth and rub gently. In exceptional cases, it may be 
necessary to apply a little xylol, ether or chloroform to the sub- 
stance, and then rub it off gently so as not to remove the lacquer. 

Stage: This is the part that supports the slide while a speci- 
men is under examination. Should the stage become soiled with 
anything which water will not remove, apply a little xylol, or 
chloroform and rub it off with a clean cloth. If the stage turns 
to a dull gray color, it may be restored to its original black by 
rubbing a little of some heavy oil on it. When the black color 
has been restored wipe the stage free from oil. If any substance 
falls on the stage it should be removed immediately. 

Inclination Joint: This joint, which permits the body of the 
microscope to be inclined at anj^ desired angle, sometimes wears 
so loose that it will not support the body properly. The joint 
may be corrected by tightening the nuts on the end of the in- 
clination axis using a heavy screw driver if the nut is slotted, 
or a "spanner" if the nut is provided with two small holes. A 
round nosed pliers may sometimes serve to turn the nut. Do 
not mar the nut with the tools. The axis pin is slightly conical 
on most modern instruments. This makes it possible to tighten 
the joint by turning the nut on the end that will draw the pin 
tighter into its bearing.* The nut on the other end may first have 
to be slightly loosened, then tightened after the cone is drawn 
in to give the necessary friction. 

Coarse Adjustment: The bearing of this adjustment should 
work so smoothly that the highest power may be easily focused 
with it. But it should hold the body of the microscope securely 
in place. If any foreign matter interferes with the working of 
the bearings rub a little xylol or chloroform on them to remove 
it. Oil the bearing with parafin oil or ' ' watch ' ' oil after they are 
thoroughly cleaned. Keep the teeth of the rack free from for- 
eign substance at all times and use judgment in making necessary 
repairs to worn parts. 



Adjustments 479 

Fine Adjustment : This is much more delicate then the coarse 
adjustment, and of limited range. The micrometer head is lo- 
cated at the top of the arm in one type while in the other there 
are two micrometer heads, one on either side of the arm. 

The micrometer head should turn easily and smoothly, yet fit 
snugly, and hold the body of the microscope at all times from 
slipping down with danger of damaging the objective lens and 
the object. The range of the fine adjustment has been reached 
when no change of focus occurs while the micrometer head is 
being turned. The micrometer head should then be turned in 
the opposite direction until nearly the middle of the range is 
reached. If the thread is turned ofi: its bearing, as may happen 
with some of the older forms of microscopes, take great care to 
start it on correctly, and not cut the thread. If there appears 
to be any unusual friction do not force it. When anything ex- 
ceptional needs repairing it is better to have it done by an ex- 
perienced mechanic, or by the maker. If the fine adjustment is 
not so constructed that it ceases to work when the objective rests 
on the cover glass, great care must be exercised in focusing so 
as not to crush the specimen or damage the lens. 

Draw Tube. This should fit snugly, work easily and smoothly, 
and be kept clean. Always support the body tube, while push- 
ing the draw tube in, and thus avoid pushing the objective into 
the slide. 

Substage: If the threads on the quick acting screw become 
gummed, and make it work hard, clean them with xylol or chloro- 
form until they work easily. Clean the leaves of the iris dia- 
phragm with the same substances if they become dirty or rusty. 
Then oil them and work it over all the parts by opening and clos- 
ing them several times. If the leaves become bent or misplaced 
have them repaired by a skilled mechanic or by the maker. When 
working with the diaphragm nearly closed make certain that no 
particles of dust or lint have collected in the edge of the opening 
and interfere with the light. 

Nosepiece: This is the part of the instrument that supports 
the objectives. When the nosepiece supports two or more ob- 
jectives the latter should be parfocal. That is, they should be 
made so that when one objective is in focus, the other also will 
be in fairly good focus if it is swung into the optical axis ; and 



480 Bacterioi^ogicaIv Tests and Cultures 

the center of the field of one lens should fall within the field of 
the others. To obtain this result each set of objectives are fitted 
to a particular nose piece, therefore objectives should not be ex- 
changed. If the nosepiece is bent, the lens will be thrown out of 
center. Use care to avoid swinging the lens into the cover glass 
when changing from a lower to a higher power. When removing 
an objective from a nose piece always support it with one hand 
while screwing it off with the other and exercise every necessary 
precaution to prevent its injury. 

The Optical Parts. The- best results cannot be obtained with 
dirty lenses. In cleaning them remember that glass surfaces are 
soiled by coming in contact with the fingers. As the glass of 
the lenses is comparatively soft avoid rubbing it hard or using 
anything but soft clean cloth or lens paper in wiping it. Chamois 
skin should never be used for cleaning a lens. Japanese filter 
paper serves best. It is not expensive, and may be obtained from 
any dealer in microscopical supplies. 

Objective. Dust may be removed from the objective with a 
camel hair brush, or by wiping it with lens paper. Breathe on 
clouded lenses before wiping them. Kemaining cloudiness may be 
removed by wiping the lens with a corner of a piece of lens paper, 
or cloth that has been dipped in alcohol, then wipe dry. For oily 
substance, dampen the corner of the lens paper or cloth with 
chloroform, benzine, or xylol before wiping the lens, then wipe it 
dry. Clean immersion objectives with lens paper immediately 
after using them. If the immersion oil has dried on, use lens 
paper or cloth dampened with xylol or chloroform, theii wipe 
dry. 

Always keep an eyepiece in the tube to prevent dust from 
falling through the tube onto the back lens of the objective. 
Bust may be removed from this lens with a camel hair brush. 
An objective is too delicate and expensive to be repaired by any 
one but an experienced mechanic. If anything serious is the 
matter it should be returned to the maker for repairs. 

Oculars: These are cleaned by wiping in the same manner 
as described for objectives. If a gray film or specks of dust 
deposit on the inner surfaces of the lenses it will be necessary to 
remove the lenses from the tube and wipe them clean. 



OpiiRATiNG Tin-; Microscopf: 481 

Condenser: It is necessary to have a clean condenser to 
enable the instrument to do its best work. In cleaning it, follow 
the directions given for cleaning the oculars. 

Mirror: Keep the surface of the mirror clean by applying 
the methods used in cleaning the lenses. 

Operating the Microscope: Location: The microscope should 
be placed on a firm table that is large enough to hold the neces- 
sary material without crowding. The table should be in a roomy 
place free from distracting influences, and of a height to make 
the position of the worker comfortable. The use of the inclina- 
tion joint and a chair, the height of which may be adjusted, will 
assist in attaining this object. When working on fluids it may 
be necessary to have the stage in a horizontal position. For this 
reason, it is advisable to become accustomed to using it in this 
position for all work. 

Practice working with both eyes open and divide the work 
by using either eye. By doing this, and not working too long in 
the beginning, several hours' work will not tire the eyes. If the 
eyes feel fatigued stop work until they are rested. Proper light- 
ing is a great help toward making the work easy for the eyes. 

Lighting : North light from windows without cross bars gives 
the best light. Direct sunlight is to be avoided, and should be 
toned down by using white shades on the windows if the sun- 
light strikes the microscope. Wire netting on the windows or 
branches of trees near them interferes with good work. In order 
to avoid shadows from the hands while manipulating the mirror 
or other parts, the operator should face the light, and use a screen 
to protect the eyes. 

Almost any strong artificial light that can be placed reason- 
ably near the microscope will serve well. It has the advantage 
of constancy, and may be used at all hours. Placing a bull's eye 
condenser between it and the mirror will assist. When examin- 
ing opaque objects it may be necessary to have the light shine 
directly upon the object in place of passing through it. For this 
work ordinary daylight, or daylight that is condensed upon the 
object by means of a lens or concave mirror, serves fairly well. 

Focusing: Place upon the stage directly' under the objective, 
a semi-transparent specimen having sharp outlines and mounted 



482 Bactivriological Tksts and Cultures 

on a slide. With the ocular in place first use an objective of 
low power in focusing. While watching the objective lens from 
the side with the eye nearly on a level with the stage, turn the 
coarse adjustment to force the body tube down until the lens of 
the objective is almost in contact with the cover glass. Adjust 
the size of the opening in the diaphragm until the lighting effect 
is good but not too strong. . Then examine the field through the 
microscope while very slowly elevating tlie tube by means of the 
coarse adjustment, to bring the specimen into focus. When the 
specimen is clearly outlinetl, bring it into a sharp focus by using 
the fine adjustment. At this point move the mirror into different 
positions trying both the concave and plane sides, until the best 
lighting eft'ect is obtained. TJie fine adjustment will have to be 
used almost continuously to bring dift'erent parts of the specimen 
into the focal field while moving it around and examining it. 
Caution must be exercised at all times while focusing to avoid 
unconsciously forcing the objective through the cover glass on 
the slide. 

If it is necessary to obtain greater detail elevate the tube of 
the microscope by means of the coarse adjustment, then care- 
fully unscrew the objective and replace it with a higher power. 
If more than one objective is attached to a nose piece and they 
are parfocal, the nose piece may be turned without refocusing 
until the higher power objective is in the optical axis. While 
turning the nose piece, or while bringing the objective down close 
to the cover glass, look between the objective and the slide, and 
move the objective very slowly to avoid contact with the cover 
glass. If the specimen is not in focus after changing the objec- 
tive, it will be necessary to refocus as in the first instance. 

Two objectives and two oculars should be provided. Their 
magnifying powers, to order in purchasing, can usually be safely 
left to the maker of the microscope after explaining the character 
of the work in which they are to be used. 

Special Suggestions: It is a good practice for beginners to 
look through the microscope and examine the field with the slide 
removed. If specks or cloudiness are visible it may be due to 
dust or other material on the lenses. Specks on the ocular will 
move in the field when the ocular is revolved. Sometimes specks 
and filaments on the vitreous humor of the eye appear to be lo- 



Use of the Microscope 



483 



cated in the microscope field. No attention should be given to 
them. When examining fluids difficulty may be experienced in 
keeping objects in the field due to motion in the liquid. It should 
be remembered that specimens of considerable depth may 
change in form as the focal plane passes up or down. Particles 
at the bottom of a liquid may come into the focal plane and dis- 
appear as the objective and local plane are raised, other particles 
or crystals coming into view. Liquid used in mounting the speci- 
mens sometimes flows out and partly covers the cover glass, thus 
interfering with a clear field, or being mistaken for the liquid 
beneath the cover. Air bubbles are frequently found in the 
liquid mounts. A little experience will usually enable one to 
distinguish them from other objects. These are only minor 
troubles, and the remedies for them are obvious. 













OCULARS 










Objec- 


Initial 
Magnifi- 
















Objec- 


tives 


















tives 


mm. 


cation 


4X 


oX 


6X 


8X 


lOX 


12X 


15X 


20X 


mm. 


48 


2.2 


8 


11 


13 


18 


22 


27 


33 


44 


48 


40 


2.8 


11 


14 


17 


22 


28 


33 


42 


56 


40 


32 


4 


16 


20 


24 


32 


40 


48 


60 


80 


22 


30-32 


2-4.5 


4-9 


5-12 


8-19 


10-24 


15-35 


18-43 


20-48 


30-70 


30-32 


25.4 


6 


24 


30 


36 


48 


60 


72 


90 


120 


25.4 


16 


10 


40 


50 


60 


80 


100 


120 


150 


200 


16 


12 


15 


60 


75 


80 


129 


150 


180 


225 


300 


12 


8 


20 


80 


100 


120 


160 


200 


240 


300 


400 


8 


5 


36 


144 


180 


216 


288 


360 


432 


540 


720 


5 


4 


44 


176 


220 


264 


352 


440 


528 


660 


880 


4 


3 


60 


240 


300 


360 


480 


600 


720 


900 


1200 


3 


1.8 


95 


380 


475 


570 


760 


950 


1140 


1425 


1900 


1.8 


1.5 


109 


436 


545 


654 


872 


1090 


1308 


1635 


2180 


1.5 



THE USE OF THE MICROSCOPE IN DAIRY PLANTS. 

The microscope can be put to many important uses in dairy 
plants. These uses include the examination of solid particles 
found in milk or in its products ; the general physical appear- 
ance of all kinds of dairy products ; the examination of fat glob- 
ules ; the examination of milk sugar crystals, and finally com- 
plete bacteriological examination of all dairy products. 

The foregoing instructions are sufficiently comprehensive to 
enable one to operate the instrument for all minor microscopical 
examinations. Complete bacteriological examinations can be 
made only by those well versed in the subject. 



k 



484 Bacterioi^ogical Tests and Cultures 

HOW TO MAKE MICROSCOPICAL EXAMINATIONS OF FAT IN 
DAIRY PRODUCTS. 

In the case of skim-milk, whole milk, and usuallj^ in the ease 
of cream, the samples can be examined without being diluted 
with water. Place a small drop upon the slide, and with the 
cover glass spread the same uniformly between the slide and the 
cover glass. Use samples of uniform size. 

In the case of evaporated milk, concentrated cream, sweetened 
condensed milk, and all other fluid condensed products, it is 
usually desirable to dilute the sample with an equal volume of 
water. This is best accomplished b}^ placing a small drop of the 
condensed product upon the slide, and then adding to it a drop 
of water of equal size, and mixing the two very thoroughly be- 
fore placing the cover glass over the same. The dilutions can 
be made in a flask using equal volume of the product to be examin- 
ed and water. 

The best results are obtained by using 10 X ocular and 4 mm 
objective. This will give a magnification of 440 diameters. 

HOW TO MAKE MICROSCOPICAL EXAMINATIONS OF MILK 
SUGAR IN DAIRY PRODUCTS. 

The products that usually contain crystallized milk sugar are 
principally sweetened condensed whole and skim-milk. Plain 
and skim condensed milk, if of too great concentration, also some- 
times contain milk sugar crystals. The defect in ice cream known 
as "sandy ice cream", is due to the presence of crystallized milk 
sugar. All of the above products should be examined without 
diluting with water, inasmuch as the addition of water might 
cause many of the crystals to go into solution. 

It is usually desirable to examine the crystals under both low 
and high magnifications. The two combinations most commonly 
used are 10 X ocular and 16 mm objective giving a magnification 
of 100 diameters ; and 10 X ocular and 4 mm objective, giving 
a magnification of 440 diameters. By means of the lower magnifi- 
cation, a large field of crystals can be examined, and the uniform- 
ity of the crystals carefully studied, while with the higher mag- 
nification the individual crystals are better defined, and the same 
can -be subjected to close study. 



Organisms Found in Mil,k 485 

BACTERIA IN MILK. 

When milk is first secreted in the udder of a healthy cow, it 
is free from living organisms since these do not usually pass 
through the tissues of the digestive tract, and through those that 
supply the udder. As the milk descends in the udder it comes 
in contact with a few bacteria that probably gained entrance 
through the opening in the teat. Others are introduced later by 
dust from the air; by dirt from the hands of the milker; by 
particles of dirt or other material that fall into the milk; or by 
contact with bacteria on the walls of containers. 

Since milk affords a food supply in a condition readily avail- 
able for their growth, bacteria that gain entrance to it soon in- 
crease in numbers by reproduction, unless rigid measures are 
practiced to check their growth, or to destroy them. 

While all bacteria are considered objectionable in fresh milk, 
and some kinds are decidely harmful, some types are utilized to 
advantage in the manufacture of butter, cheese, and fermented 
milk products. For all of these reasons dairy bacteriology has 
been extensively studied, and methods of sanitary control de- 
veloped. The application of these methods adds considerably to 
the labor of handling milk, and to the cost of equipment for 
preserving it. 

The number of bacteria in a sample of milk ordinarily has 
little significance when the history of the sample is unknown, but 
where the bacterial count is high, and the sample's history is 
known, it may indicate that something is wrong, and thus be- 
come the basis for starting an investigation. Upon the other 
hand, a low bacteria count — other factors being considered, is 
usually an indication of good sanitary quality. The bacteria 
count and especially the determination of the kind of organisms 
present, is of unquestioned value to the industry for the purpose 
of locating and removing sources of contamination, and for 
measuring the effectiveness of sanitary methods. 

Types of Organisms Found in Milk. The organisms found in 
milk consist of bacteria, and usually a few yeasts and moulds. 
They comprise the lowest form of life in the vegetable kingdom, 
and like other plants, they must have suitable food and surround- 
ings in order to grow. As many bacteria are unable to move by 



486 



BacterioIvOGicaIv Tests and Cultures 



their own effort, and the others have only limited means of move- 
ment, all require a very moist, or liquid medium with a readily 
available food supply. Milk is a fluid of this character, and it 
meets the requirements of a number of varieties, although some 
after gaining entrance to it are unable to develop, and soon 
perish. 




Fig-. 115. 



Microscopic Siibstances Found in Milk, Sliowing Relatives Sizes, 
According to Melick.^ 



The above cut represents a portion of a drop of milk. F, fat 
globules ; L, leucocytes ; Y, yeast ; and B, b, c, s, t, 1 and 2 seven 
species of bacteria frequently found in milk. B represents the 
hay bacillus group ; b represents one species of bacillus viscosus 
which forms slimy milk ; c represents a streptococcus ; t represents 
bacillus typhosus ; 1 represents tetragenococci, and 2 one of the 
lactic acid group. 

Attempts have been made by a number of investigators to 
classify bacteria in groups, and describe varieties by their special 
properties. But' many difficulties have arisen because some of 
the properties of bacteria are transitory or extremely variable. 
It appears that permanent identifying characteristics, if they 
exist, are not understood with such clearness that it permits 
a satisfactory classification at present. The grouping that has 
been made, however, is used to advantage for the purpose of 



Orc.anisms Found in Milk 487 

separation, study and description. The group name is usually 
derived from the most pronounced characteristics of the type. 

In this way the principal organisms that are nearly always 
present in milk may be placed in two groups, namely the Bacillus 
lactis acidi group, and the Bacillus lactis aerogenes group includ- 
ing Bacillus eoli communis. The members of the former group 
vary in their ability to produce lactic' acid but do not develop 
gas. The varieties that produce lactic acid and curdle the casenj 
rather promptly are most universally distributed. Their presence 
like the presence of all bacteria is very undesirable in all fresh 
milk, but in the form of pure cultures some are used to advantage 
in the manufacture of butter, most varieties of cheese, and sonr 
milk beverages. The characteristics of this group of organisms 
are described under S. lacticus Kruse, p. 490 and B. lactic acidi 
Leichmann, p. 491. 

The members of B. lactis aerogenes, and B. coli communis 
groups are frequently present in milk. They are very commonly 
the source of fermentations that cause trouble and loss to tVte 
dairy industry. Some of the varieties of these groups are de- 
scribed under Acid Gas Producers, p. 495. 

A group of liquefying organisms, characterized by their ability 
to liquefy gelatin, not uncommonly cause the loss of dairy prod- 
ucts. They digest casein and have the power to bring about 
decidedly putrefactive decomposition. B. Subtilis is a spoi-e- 
bearing organism of this type. It sometimes causes the decom- 
postion of evaporated milk that has not been properly sterilized. 
Also, the pronounced bitter taste that sometim.es develops in 
whole milk and in evaporated milk may be due to protein decom- 
position products developed through the action of the members 
of this group. 

Another group sometimes known as Bacterium caucasicum 
is of some importance in the dairy industry principally because 
a few types are used in the production of fermented milk bever- 
ages. The better known variety is Bacillus Bulgaricus. When 
used as a pure culture it yields a buttermilk having a sharp acid 
flavor and heavy body. Sometimes from 5 to 15 parts of the 
pure culture is added to 100 parts of a pure culture of Bacillus 
Lacticus in order to give the resulting buttermilk a more pro- 
nounced acid flavor and heavier body. The use of Bacillus 



488 Bacterioi^ocicai, Tests and Cui.turi-:s 

Bulgaricus in the making of commercial cnltured bnttermilk is 
on the decline. 

Yeasts and torula are occasionally the cause of pronounced 
fermentation with production of gas in cream, is condensed 
milk, and in ice cream. In cream it causes foaming and prevents 
the fat globules from gathering in the churning process. It is 
liable to appear, with generous production of gas in sweetened 
condensed milk, and in ice cream when manufactured in un- 
sanitary surroundings or from infected products, and then held 
for a time. 

A few pathogenic organisms can live and develop in milk, 
and thereby disease may be transmitted to man. For this reason, 
their study is of importance in dairy bacteriology. The best 
protection for the public, however, is the practice of pasteurizing, 
and exercise of every reasonable precaution to keep the milk 
free from contamination. 

Wilcox'- drawing upon data from numerous sources con- 
cisely describes "the morphological characters, biology, and 
behavior of the pathogenic and saprophatic bacteria that have 
been found in milk". His description of several of the more 
important types are reproduced in the following paragraphs : 

PATHOGENIC BACTERIA MOST FREQUENTLY FOUND IN 

MILK. 

Bacillus tuberculosis Koch. 

Morphology. — fSlender, slightly bent, pointed ends, sometimes 
threads and branched forms, or club forms, longer in milk than 
in tissues, occurring singly or in twos, tliree or colonies. Size 
1.5 — 4X .4m. (m = micron). Acid — fast. Gram and Ziehl-Neel- 
sen stains positive. No spores or flagella. Non-motile. Capsule 
stains. Bouillon. — Growtli in 7 or 8 days if glycerine is added. 
Sometimes pellicle. Glyceriue-agar. — Growth begins in 6-12 
days. Colonies minute, whitish-yellow, later brown, lichen-like, 
elevated, sinuate, dry or moist. Potato. — Decided growth in 2 
or 3 weeks, best if potato is moist, small crumb-like masses, 
friable, yellow, dull. Blood serum. — Growth begins in 10-12 
days. Serum not liquefied. Colonies light, dry crumb-like coal- 
escing scales. Pathogenic for man and other animals. Aerobe. 
—Growth from 22° to 42° C, but best at ;{7= C. 



Organisms Found in Milk 489 

B. typhosus Eberth. 

Morphology. — Takes ordinary stains, Gram stain negative. 
Short, plump, rods, longer in cultures. Size 1-3 X .6 — .8m. cap- 
sule. Motile, 8-14 long flagella. Occurs in threads. Serpentine 
movements. Vacuoles in stained and unstained preparations but 
no spores. Bouillon. — Turbidity, abundant sediment. Gelatine 
plates and tubes. — Small, yellowish-white, punctiform, raised 
center, wavy elevations under microscope. In stab cultures gran- 
ular, grayish-white thread growth. Streaks culture similar, non- 
liquefying. Agar plates and tubes. — Colonies irregular, round, 
grayish-white, slightly raised, yellow line extending outward 
from the center. In stab cultures granular, grayish, thread 
growth with irregular outline and oily lustre, later yellow. On 
streak cultures spreading, wavy, smooth edge, shiny. Milk. — 
Appearance unchanged, not coagulated, slightly acid. Potato. — 
Variable. Delicate and moist, grayish or rarely brownish. May 
be readily differentiated from B. coli by the fact that the latter 
coagulates milk within 48 hours with abundance of acid. B. 
typhosus grows best as aerobe but also as anerobe and in CO. 
Produces typhoid fever in man, and a fatal intoxication in animals. 
Grows best at 37° C. on all ordinar}^ media, less well on non- 
albuminous media. No pigment nor iiidol. No gas in lactose. 

B. diphtheriae Klebs-Loeffler. 

Morphology. — Slightly curved rods usually with one end club- 
shaped and the other pointed, or may be short wedge shaped, com- 
ma shaped, or dumb bell form. Size 1.2-2 X .3-. 5m. In groups 
of 2-4, no long chains. Stained by aniline dyes. Gram, Loetfler 
and Nicolle. Capsule. No flagella. Non-motile. No spores. 
Bouillon. — Dust like granules, usually pellicle. Produces indol, 
acid and nitrites. Gelatine. — Yellowish-white, slightly elevated 
surface, non-liquefying, non-characteristic. Agar plates and 
tubes. — In 24 hours circular, round, white elevated colonies with 
smooth edges and moist. Potato. — Little or no growth if acid, 
scanty after a few days if alkaline. Milk — Abundant growth, 
amphoteric reaction, no curdling. Blood serum. — Rapid at 37° 

C. Characteristic within 12 hours, round, raised, grayish-white 
colonies, yellowish, translucent if young, moist, margin irregular, 
center thickened and opaque. Colonies not confluent, may reach 



VJU Bactkriological Tests and Cultures 

size of 4 or 5mni, Abundant growth on hen's eggs. Grows best 
at 37* C. Qnickly killed at 60° C. Aerobe. 

Streptococcus of contagious mammitis. 

Morphology. — Long, undulating chains, elements Im in diam- 
eter, shorter in old than in recent cases of mammitis. Aerobe or 
anaerobe. Takes analine dyes, but Gram stain poorly. Gelatin. 
— Small, translucent, whitish colony. Pellicle. Potato. — Poor 
growth. Bouillon. — Growth after 24 hours. Sediment, no turbid- 
ity. Milk. — Rapid growth. Curdled in 24-48 hours, strongly 
acid. Causes mammitis in cows and goats. A smaller form 
causes gangrenous mammitis in sheep. Possible cause of sterpto- 
coccie sore throat in children. 

Streptococcus scarlatinae Klein and Gordon. 

Morphology. — Polymorphic streptococcus with all transition 
stages between coccus and bacillus. Coccus forms prevails in 
bouillon, bacillus on agar. Takes simple stains and Gram. 
Bouillon. — After 24 hours at 37'' C. a single, coherent, white-gray 
mass appears at base of tube, floating as a flat conglomerage in 
the fluid medium. Gelatin. — Slow, small, gray, circular, firm 
edge. No liquefaction. Chain formation conspicuous. Agar. — 
After 24 hours colonies are gray, granular, irregular, tubercula- 
ted ; or similar without tubercles ; or with a frill of chains around 
a compact center. Milk. — Rapid curdling, acid. Blood serum, — 
Good growth of colonies. Aerobe. Found in cases of scarlet fever 
and sometimes thought to be the cause of the disease. Occurs 
also in diseased udders of cows. Pathogenic for mice and rab- 
bits. 

BACTERIA PRODUCING ACID BUT NO GAS. 
Ordinary Types Most Frequently Found in Milk. 

S. lactis viscosus Conn. 

• Morphology. — A streptococcus. Size .8-. 9m. Gram stain posi- 
tive. Gelatin colon3\ — Shiny, pale, yellow, round or lobate, 
usually viscous. Gelatin stab. — Needle and surface growth, pro- 
ducing a nail culture. Agar streak, — Lobate, luxuriant, vis- 
cous. Fermentation tubes. — Acid in all sugar bouillons and 
growth in the closed arm but no gas. Bouillon. — Sediment, tur- 
bidity and pellicle. Milk. — Acidified, curdled and rendered very 



Organisms Found in Milk 491 

slimy. Potato. — Luxuriant, dull, pasty growth. Grows at 20^ 
and 37° C. Facultative anaerobe. Variety A shows scanty, non- 
viscous growth on agar and no pellicle on bouillon. 

S. lacticus Knise. 

Morphology. — Long or short chains. Size .5-lm. Gram stain 
positive. Gelatin colony. — Minute, white, rough, dense. In lit- 
mus gelatin always acid. Gelatin stab. — Moderate needle grow^th, 
but no surface. Agar streak. — Barely visible, faint tilm. Fer- 
mentation tubes. — Acid in all sugars, usually growth in closed 
arm but no gas. Bouillon. — Almost invisible, slight sediment and 
turbidity. Milk. — Promptly acidified and curdled. Potato. — 
Uusually invisible. This species sometimes comprises 99 per cent 
of all the bacteria in a sample of milk. The type 8. lacticus I 
produces acid in dextrose but not in other sugars. Variety A of 
this type shows no turbidity but a slight pellicle in bouillon, • 
variety B, turbidity but no pellicle, variety C turbidity and 
pellicle with negative Gram stain, variety D luxuriant growth on 
potato. The type S. lacticus II produces acid in lactose and 
saccharose but not in dextrose. Gram stain negative. S. lacticus 
III shows pellicle on bouillon and acidifies or curdles milk. 

M. lactis Fluorescens Conn. 

Morphology. — Size .5 - .6m. Gram stain negative. Gelatin colo- 
n3\ — Round. Moderately thick, smooth, with greenish lique- 
faction. Gelatin stab. — Stratiform. Agar streak. — Luxuriant, 
narrow, thick, smooth, white. Fermentation tubes. — Dextrose 
acid, other sugars alkaline, no gas or growth in closed arm. 
Bouillon. — Sediment, turbidity, pellicle. Milk. — acidified, curdled, 
digested. Potato. — Scanty, thin, smooth, white. Grows at 20° 
and 37° C. Facultative anaerobe. 

M. lactis variens Conn. 

Yellow coccus, common in milk. Morphology. — Size .4-1.4m. 
Gram stain positive. Gelatin colony. — Deep and opaque or super- 
ficial and white, usually acid in litmus gelatin. Gelatin stab. — 
Napiform, liquefaction sIoav or rapid, sometimes a dry pit. Agar 
streak. — Luxuriant, rough, spreading pale orange. Fermentation 
tubes. — Acid in all sugars, closed arm growth, no gas. Bouillon. 
— Flocculent sediment, slight turbidity or pellicle. Milk — Acid, 
commonly curdled and digested. Potato. — Luxuriant or scanty^ 



492 BacterioIvOGicaIv Tests and Cultures 

pale orange, frequently dry. Grows better at 37'' than at 20° C. 
Facultative anareobe. Variety A produces acid only in dextrose 
and does not acidify milk. 

Sar. lactis aurantiaca Conn. 

Orange, liquefying. Morphology. — Size Im, Gram stain posi- 
tive. Not motile. Gelatin colony. — Liquefying pit, orange pig- 
ment. Gelatin stab. — Slow liquefaction, stratiform. Agar streak. 
— Filiform, raised, smooth, moist, orange. Fermentation tubes. — 
No acid, gas or closed arm growth in any sugar. Bouillon. — Pel- 
licle, slight sediment. Milk. — No change in reaction, curdling, 
digestion. Potato. — Spreading, capitate, luxuriant. Grows at 
20° and 37° C. Aerobe. 

B. lactis Viscosus Adametz. 

Slimy milk bacteria. Morphology. — Size. .5-1.2 x .5 - 2.5m. 

Filaments 15m long. Gelatin colony. — Flat, lobate, viscous. 
Gelatine stab. — Needle growth sometimes granular, thin, shiny, 
gray surface. Agar streak.— Luxuriant, viscous, white. Fer- 
mentation tubes. — No acid, gas or closed arm growth. Bouillon. — 
Sediment, turbidity, pellicle. Milk. — Alkaline, slimy, not 
curdled. Potato. — Thick, uneven, dirty gray. Grows at 20° 
and 37° C. Aerobe. 

B. lactis acidi Leichmann. 

Immensely numerous. Common cause of sour milk. Several 
varieties differing from type form. Morphology. — Size .7 - 1.2 x 
.5 - .8m. Sometimes cocci. Gram stain positive. No motility, 
spores or long chains. Gelatin colony. — Small points, opaque, not 
characteristic, mostly below surface. Acid on litmus gelatin. 
Gelatin stab. — Granular or linear needle growth, no surface. Agar 
streak. — No growth or barely visible, better on milk agar. Fer- 
mentation tubes. — Acid in all sugars, commonly closed arm 
growth, no gas. Bouillon. — Sometimes no growth, commonly 
slight sediment. Milk. — Acid, promptly curdled without gas, no 
digestion. Potato. — Thin, transparent or no growth. Grows 
better at 20° than at 37°. Facultative anaerobe. Variety A has 
a minute colony. Milk sometimes curdled in 6 hours. Variety B 
has a dense surface colony. Variety C is more anaerobic. Vari- 
ety D never curdles milk. 



Organisms Found in Milk 493 

B. lactis burri Conn. 

Reddish bitter-milk organism. Morphology. — Size 1.3 x .7m. 
No chains, spores or Gram stain. Gelatin colony. — Surface in 
liquefying area 1-3 mm. in diameter. Gelatin stab. — Begins to 
liquefy in 4 days, infundibuliform. Agar streak.-j^Luxuriant, 
smooth, lobed, reddish. Fermentation tubes. — No acid, gas or 
closed arm growth. Bouillon. — Turbidity, no sediment or pellicle. 
Milk. — Acid, not curdled or digested. Potato. — No growth. 
Grows at 20°, not 37°. Aerobe. 

B. lactis fluorescens Conn. 

Morphology. — Size 1.4, - 1.5 x .8 - .9m. No chains, spores, 
capsule or Gram stain. Gelatin colony. — Slow, race-like, dense 
center. Gelatin stab. — Needle growth, stratiform, liquefaction in 
one day. Agar streak. — Filiform, translucent, smooth, white, 
green fluorescence. Fermentation tubes. — No gas or closed arm 
growth, acid in dextrose and saccharose. Bouillon. — Sediment, 
turbidity, pellicle. Milk, — Alkaline, curdled at 20° C, digestion. 
Potato, — Filiform, raised, white. Grows at 20°, poorly at 37° C. 
Aerobe. 

P. lactis varians Conn. 

Common in milk. Morphology, — Size 1 - 1,4 x 8m, Chains, 
No spores, capsules or Gram stain. Gelatin colony, — Round, flat 
or umbilicate, rugose, brownish. Gelatin stab. — Stratiform or 
infundibuliform, slow. Agar streak, — Filiform, raised, opaque, 
white. Fermentation tubes. — No gas or closed arm growth, 
usually acid in dextrose only. Bouillon. — Sediment, turbidity, 
membranous pellicle. Milk. — slightly acid and curdled at 20° C, 
not at 37° C. Potato. — Variable, white to brown. Grows better 
at 20° than at 37° C. Aerobe Variety A. liquefies rapidly. B. 
acidificans presamigenes casei Gorini and P. fragariae probably 
belong here. 

B. lactis citreus Conn. 

No chains or spores. Size .8 x .5m. Gelatin colony. — White, 
opaque, later yellow. Gelatin stab. — Needle growth, lemon — yel- 
low surface. Agar streak. — Luxuriant, lemon-yellow, smooth. 
Fermentation tubes. — Probably acid without gas. Bouillon. — 
Sediment, turbidity, pellicle. Milk. — Acid, curdles. Potato. — 



494 Bacteriological Tksts and Culturi-s 

Luxuriant, white, then lemon yellow. Grows at 20° and 37^ C. 
Aerobe. 

B. lactis rubifacens Gruber. 

Bed pigment. Morphology. — Size 2 - 3 x .7m, Spores, no chains, 
capsule or gram stain. Gelatin colony. — Thick, gyrose, white. 
Gelatin stab. — Needle growth villous, spreading surface. Agar 
streak. — Linear, moderate, white. Fermentation tubes. — Acid 
and closed arm growth, no gas. Bouillon. — Sediment, turbidity, 
ring pellicle. Milk. — Acid, curdled like jelly. Potato. — Thick, 
white. Grows better at 20° than at 37" C. Facultative anaerobe. 

B. Subtilis. 

Very common in milk. Morphology. — Size 1.5 - 4 x .6 - 1,5 
mm. Chains, spores, no capsule. Gram stain positive. Gelatin 
colony. — Rapid liquefaction, irregular granular masses. Gelatin 
stab. — Liquefies in one day. Crateriform, later stratiform. Agar 
streak. — Filiform, spreading, cretaceous, wrinkled. Fermentation 
tubes. — No acid, gas or closed arm growth. Bouillon. — Sediment, 
turbidity, pellicle. Milk. — Alkaline, curdled, digested. Potato. — 
spreading, gray, raised, dry or moist. Grows at 20° and 37° C. 
Aerobe. Varieties with slow liquefaction and negative Gram 
stain. 

This bacillus, — also frequently called "Hay Bacillus," on ac- 
count of having been first found in hay, as well as other members 
belonging to the same group to which this one belongs, are among 
the most important encountered in the dairy industry. Spoilage 
in the case of improperly sterilized evaporated milk is usually due 
to the presence of this bacillus. 

Fig. 116 and 117 illustrate this bacillus in two forms. 

B. lactis gelatinosus Conn, 

Produces jelly-like milk. Morphology, — Size ,8 x ,6 m. No 
chains, spores, capsule or Gram stain. Gelatin colony, — Round, 
smooth, white, slow. Gelatin stab, — Slow, crateriform, white. 
Agar streak. — Filiform, raised, smooth, brownish. Fermentation 
tubes, — No acid, gas or closed arm growth. Bouillon. — Sediment, 
turbidity, membranous pellicle. Milk. — Acid, curdled, digested 
into jell3^ Potato, — Moderate, raised, brownish. Grows at 20° 
and 37° C, Aerobe, 



Organisms Found in IMilk 



495 



B. mesentericus fuscus Conn. 

Morphology. No chains. Size 1.2 - 1.5 x .4 - .6m. Central 
spores, gram stain positive. Gelatin colony. — Round, convex, en- 
tire, brownish-red. Gelatin stab. — Slow, napiforra. Agar streak. 
— Spreading, thin, rugose, gray. Fermentation tubes. — o gass or 
closed arm growth. Acid in dextrose and saccharose. Bouillon. — 





rig-. 116. Bacillus Sutotilis." Vegretating- Rods from a Very Young Culture of 
Ag-ar. Bacilli Showing Flagella. 



nfii^ts 



1 



>' * 







Fig: 117. Bacillus Subtilis and Spores.' The Spores Have Very Thick Cell 
Memhrane Almost Impenetrable by Heat, 



496 Bacteriological Tests and Cultures 

Slight turbidity, no sediment or pellicle. Milk. — Alkaline, 
curdled, digested. Potato. — Luxuriant, thin, rugose, brownish- 
red. Grows better at 37° than at 20'' C. Aerobe. 

ACID GAS PRODUCERS. 
Bacterium aerogenes type. 

B. lactis aerogenes Esch. 

Morphology.— Size 1.4- 5 X 1 -1.5m. Sometimes capsule. No 
chains or spores. Gram stain irregular. Gelatin colony. — Thick, 
round, smooth, moist, sometimes viscous, 2 mm. in diameter. Gela- 
tine stab. — Needle growth, thick, white surface. Agar streak. — 
Luxuriant, moist, gray. Fermentation tubes. — Acid, gas and 
closed arm growth in all sugars. Bouillon. — Sediment, turbidity, 
usually pellicle. Milk. — Strongly acid, curdles, gas. Potato. — 
Luxuriant, dirty white. Grows better at 37° than at 20° C. 
Aerobe. No indol. One variety produces indol, a second a thick 
colony, and two others bitter milk. 

The Coli Communis type. 
B. Coli aerogenes Conn. 

Flagellate. Morphology. — Size 1-3x1- 1.4m. No chains, 
spores or Gram stain. Gelatin colony. — Prominent, thick, smooth, 
moist, large. Gelatin stab. — ^Needle growth, thick white surface. 
Agar streak. — Filiform, raised, smooth opaque. Fermentation 
tubes. — Acid, gas and closed arm growth, not much gas. Bouillon. 
— Sediment, turbidity, usually pellicle. Milk. — Strongly acid, 
curdles with gas. Potato. — Luxuriant, white or straw color. 
Grows better at 37° than at 20'' C. Aerobe. Indol produced, or 
sometimes not. 

B. coli communis Esch. 

Like the last species, but produces a thinner, umbonate colony 
on gelatin with a granular lobate edge. Indol is produced. B. 
coli is very common in milk on account of the frequent contamina- 
tion with feces. 

Typical characters. Morphology. — Size l-1.6x.4-lm. No 
chains, spores, capsule, or Gram stain. Flagella peretrichic. Gela- 
tin colony. — Thin, spreading umbonate, smooth center, lobate. 
Gelatin stab. — Filiform needle growth, spreading, moderate sur- 



Organisms Found in M11.K 497 

face. Agar streak. — Filiform, raised, smooth, white, sometimes 
lobed. Fermentation tubes. — Acid, gas, and closed arm growth 
in all sugars. Bouillon. — Turbidity, sediment, ring pellicle. Milk. 
— Acid, curdling, no digestion. Potato. — Moderate, smooth, gray- 
white. Grows better at 37° than 20° C. Aerobe. Indol produced. 
One variety produces gas in dextrose only, and another renders 
milk slimy. 

P. Coli communis Conn. 

Gas-producing Pseudomonas. Morphology. — Size 1 - 1.5 x 
.8 - .9m. No spores, chains, capsule or Gram stain. Gelatin colony. 
— Round, thick, smooth, auriculate, gray. Gelatin stab. — Fili- 
form, umbonate, bluish sui-face. Agar Streak.— Moderate, linear, 
raised, gray. Fermentation tubes. — Acid, gas and closed arm 
growth. Bouillon. — Sediment, turbidity, flocculent pellicle. Milk. 
— Acid, curdling, no digestion. Potato. — Moderate, thin, spread- 
ing. Grows better at 20° than at 37° C. Facultative anaerobe. 
Almost identical with B. coli communis except that there is only 
one flagellum, which is long and characteristic. 

Common types of fungi found in milk. 

In addition to the bacteria which may occur in milk and cause 
various changes in it a number of fungi other than bacteria may 
gain entrance to milk. Of these perhaps Oidium Lactis and 
Torula amara are most common. Brief descriptions of these fungi 
may be given in this connection. 

Oidium lactis. 

This is the conidial form of a mildew belonging to the same 
geJius with the powdery mildew of the grape. It occurs normally 
in sour milk. Morphology. — Fruiting hyphae simple, erect, color- 
less, bearing at the tips chains of conidia which germinate to form 
septate hyphae. Takes ordinary aniline stains. The spores or 
conidia are short cylinders. Gelatine. — Colonies at first white 
points, becoming stellate and finally covering the entire surface 
with a mycelial network. Makes similar growth on agar. 

Torula amara Harrison. 

Morphology. — Oval cells. 7.5 - 10 m. long, showing vacuola- 
tion after a few days, budding at smaller end of cell. Singly or 
in clumps or chains. No spores. Wort. — Abundant growth at 



498 Bactkriologicai, Tksts and Cultures 

25° C. No pellicle. Yeast rings form at 37° C. Wort Gelatin. — 
Pin-point colonies becoming round and grayish white in 4 days. 
Gelatin stab. — Beaded line becoming dense and spiny. Surface 
waxy becoming brown at center. Wort Agar. — Rapid, luxuriant. 
Agar. — Glistening, flat. Potato. — In 3 , days slightly raised, yel- 
lowish growth. Milk. — Bitter in 5 or 6 hours, curdled in 10 days, 
much gas, no butyric acid, 

QUANTITATIVE DETERMINATION OF ORGANISM IN MILK. 

Laboratory and apparatus : The suggestion given in Chapter I 
should be found helpful in fitting out a small laboratory but much 
will depend upon the ingenuity of the individual, the space avail- 
able, and the funds that may be used for purchasing equipment. 
Where a room is used for a variety of purposes, there is likely 
to be an excess of dust whereas bacteriological work should be 
carried on in a place as free from dust as. possible. It would 
therefore be well to x>artition off a portion of the room where 
sterile apparatus and the reagents may be kept and the plating 
and other work may be done. As plenty of light is necessary, the 
partitions may be made largely of glass. 

The autoclave or steam sterilizer should maintain a steam 
pressure of at least 10 pounds to insure convenient and'reasonably 
quick means for thoroughly sterilizing the media and water. 
Any kind of an oven that can be maintained at a temperature of 
175° C will serve as a sterilizer for glassware. It should be fitted 
with a thermometer. An incubator, in which the temperature can 
be accurately controlled is indispensable. It is much better to 
purchase a good one especially designed for the purpose than to 
try to use a cheaply built substitute. 

Methods : The American Public Health Association published 
in 1921 Standard Methods for the Bacteriological Examination of 
Milk.'' As these methods are representative of the best work in 
America they are given here.'' 

COLLECTION OF SAMPLES FOR BACTERIOLOGICAL COUNTS. 

Although the technique of the plating method is funda- 
mentally dift'erent from that involved in microscopic counting, 
microscopic counts are readily made from the same samples as 
those used in making agar plates. As the precautions necessary 



Cor.Livcriox or Sami'Lf:s 499 

for securing a fair sample are identical, the method of collecting- 
samples for both methods are des bribed under a single heading. 

All collecting apparatus, glassware, pipettes, collecting tubes, 
bottles, etc., shall be sterilized at a temperature of at least 175° C. 
for one hour. 

Each sample shall consist of at least 10 cc. of milk. Before 
taking the sample the milk shall be mixed as thoroughly as pos- 
sible. If the original container can be inverted the mixing of the 
milk should be done by inverting it several times. If this is 
impossible, the milk should be stirred wth some sterile stirrer. 
Any stirrer already in the container may be used. If there is 
none in the container, the sampling pipette (or any other sterile 
article) may be used ; but it shall be used for one container only 
until it is again sterilized. 

A sample merely poured from a large can is not a fair sample 
unless the milk in the can is thoroughly stirred. Neither is a 
sample of mixed milk, taken after it is poured into an unsterilized 
weighing vat, a fair sample from which to judge the quality of 
the milk before it was poured into the vat. The sample shall be 
taken from cans by means of a glass or aluminum tube with 
straight sides, long enough to reach the bottom of the original 
container and inserted, not too rapidly, with the top of the tube 
left open. This will result in the tubes containing a cylindrical 
section of the milk from top to bottom of the can. The finger 
then placed on the top of the tube will make it possible to with- 
draw the tube full of milk and transfer it to the sampling bottle. 
The sampling bottle should be large enough to hold the entire 
contents of the tube, all of which must be reserved as the sample. 
Each tube shall be used for collecting a single sample only, and 
must be washed and sterilized before it is used again. If the 
sample is taken from a bottle, the bottle should be first shaken 
to ensure thorough mixing and the milk may be poured into the 
sample bottle, although it is better here also to use a sampling 
tube. 

If the temperature of the milk is desired, it should be taken 
from a different container from that used for the bacteriological 
sample, or after the bacteriological sample has been withdrawn. 
All records shall be made immediately after taking the sample. 
The milk sample shall be placed in a properly labeled bottle. The 



500 Bacterioi^ogical Tests and Cultures 

most convenient kinds of sample bottles are glass stoppered, or 
those closed with a cork lined screw cap. Cotton plugs are not 
satisfactory method of closure. The sample bottles shall be 
placed at once in a carrying case containing cracked ice, so that 
the milk is promptly cooled to near the freezing point. 

The samples shall be transferred to the laboratory as quickly 
as possible and shall be plated with as little delay as possible. 
The samples placed in cracked ice and water may be kept for 
several hours (12) without an appreciable increase in bacteria. 
If the plates are not made within four hours from the time of 
collection, the number of hours that did elapse should be stated 
in the report. If the milk is kept at 40° C. a slight and somewhat 
variable increase may be found in twelve to twenty hours. Up to 
twenty hours this will not be more than 20 per cent in normal 
cases. The larger increases may be expected in milk which has 
been stored at low temperatures for some time previous to sampl- 
ing. Continued shaking of the milk during its transit to the 
laboratory tends to break up the clumps into smaller masses and 
so increases slightly the number of colonies. 

In the case of samples to be used for direct microscopic 
examination, icing of the samples may be dispensed with under 
some conditions where it is possible to add preservatives (forma- 
line 2 to 3 drops of a 40 per cent solution of formaldehyde for each 
10 cc. of milk) to the samples as taken. Samples containing pre- 
servatives that have been allowed to stand until the cream is 
compact are not satifactory, and are likely to give a lower count 
than fresh samples. 

(A) MACROSCOPIC COLONY COUNT (PETRI PLATE METHODS). 

Composition of medium. 

Standard beef extract agar* shall be used for all routine work 
and shall contain the following ingredients :** 

Agar (oven dried) 1.2% 

or 



*Beef infusion may be substituted for beef extract in those laboratories 
where past records are based on the use of beef infusion agar; but in the 
interest of uniformity, it is urged that beef extract be used. 

**Thi,s medium is essentially the same as that recommended in the last 
edition of the Standard Methods of Water Analysis except for the reaction 
preferred. 



Composition of Medium 501 

Agar (market) *. 1.5% 

Beef extract ' 0.3% 

Peptone 0.5% 

Distilled water 

The beef extract shall be Liebig's where this is obtainable, or 
some other brand giving comparable results. 

Witte peptone, if available, can be used with assurance that 
the reaction of the medium will be neutral (pH=7.0) ; other 
brands — such as Armour's, Digestive Ferments Co.'s, Parke Davis 
Co.'s, — although more acid can often be used for milk analysis 
without necessitating change of reaction ; and nearly any good 
commercial peptone may be used with comparable results pro- 
vided special attention be given to H-ion concentration of the 
medium. 

The agar must be of the best quality. If oven-dried at 105° C. 
just before using, take 1.2% ; if used just as obtained in the 
market without oven-drying, use 1.5%. Remove salts and any 
dirt present by soaking, washing and draining. Distilled water 
is to be used for dissolving the ingredients. 

Reaction, 

A medium consisting of the above ingredients, including a 
suitable peptone, ordinarily has a reaction between pH^6.2 and 
7.0. If within these limits, the reaction requires no adjustment 
for m.ilk analysis. The most desirable reaction is about pH=6.5 
to 6.6 ; but any reaction between pH^6.2 and 7.0 is allowable. 
No change in reaction should be made without carefully deter- 
mining the H-ion concentration of the finished medium by the 
method described below. 

Inasmuch as the range of H-ion concentration recommended 
for water analysis^ is pH==6.8 to 8.4, it is permissible, if desired, 
to use a single agar for both purposes with a reaction of pH=6.8 
to 7.0. If Witte's peptone is used in the above formula, this will 
ordinarily be the reaction without adjustment. 

Each batch of finished medium should be tested before use as 
to its final reaction after sterilization. This test is to be made 
as follows : 

Put 4 cc. of distilled water at 30 to 40° C. (not warmer) in a 
test tube. Add 1 cc. of the agar to be tested and then 10 drops 



502 BacterioIvOGical Trsts and Cultures 

of the indicator, brom thymol blue* (0.04 per cent solution in 95 
per cent alcohol). The resulting color should be either a yellowish 
green or vary to a deeper shade of grass green. To one whose 
eye is trained this shade of color is sufficient. 

These shades may be accurately determined by means of the 
buffered solution'' of Sorensen or of Clark and Lubs. 

However, they may be approximately determined by comparing 
the tube of agar containing the indicator with a set of color tubes 
after the method of Barnett and Chapman.^" 

Select 12 test tubes of even caliber and place in two rows of 
6 each. In each tube of one row put 5 cc. of a dilute alkali (as, 
for example, twentieth normal sodium hydroxide). In each tube 
of the other row put 5 cc. of very dilute acid (one drop of con- 
centrated sulphuric or hydrochloric to 100 cc. of distilled water is 
sufficient). Avoid stronger acid. 

Add indicator to the tubes as follows : 



Acid tubes 


Alkali tubes 


H-ion 
concentration 


9 drops 


1 drop 


pH 6.2 


8 drops 


2 drops 


pH 6.4 


7 drops 


3 drops 


pH 6.7 


6 drops 


4 drops 


pH 6.9 


5 drops 


5 drops 


pH 7.1 


4 drops 


6 drops 


pH 7.3 



The tubes are to be viewed in pairs of acid and alkali, each 
pair containing the sum of ten drops of indicator. 

If preferred, double these quantities may be used throughout 
and the indicator measured in fractions of a cubic centimeter 
instead of drops. That is, two cc. of agar should be taken for 
testing. This should be added to 8 cc. of distilled water. One 
cc. of indicator should be used. In comparing with the Barnett 
and Chapman tubes, use 10 cc. of dilute acid or alkali in each 
tube, and add the indicator in tenths of a cubic centimeter instead 
of in drops. 

All of the test tubes used in this determination must be of the 
same diameter and of clear glass. 



•Prepared by Hynson, Wescott & Dunning, Baltimore, Md. 



Pri;paration of Agar 503 

Another indicator, brom cresol purple,* (0.04 per cent solution 
in 95 per cent alcohol) may be used as an alternative for brom 
thymol blue. Its use is especially desirable if the reaction of the 
agar is more acid than pH=6.4, because brom thymol blue is not 
very sensitive at this point. Brom cresol purple, on the other 
hand, is not sensitive at pH=::7.0 and therefore cannot be used if 
the medium is of neutral reaction. 

The pH values corresponding to the color pairs (acid and 
alkali) prepared by the method of Barnett and Chapman have 
been worked out b}^ Medalia.^'^ The color of brom cresol purple 
is a good shade of purple at pH=6.8 with increasingly lighter 
shade to pH=6.2. At pH=6.0 the color is a grayish hue not 
easily confused with that of pH==6.2. 

Adjustment of reaction. 

If the correct color of the indicator does not appear in the 
agar as tested, add dilute NaOH (e. g. N/20) from a burette 
until the shade is obtained which represents the desired H-ion 
concentration, that is between pH=:6.8 and 7.0. Fifty times the 
amount of N/20 NaOH added from the burette equals the amount 
of normal NaOH to be added to one liter of the medium if 1 cc. of 
the agar is being tested. When testing 2 cc. of agar, multiply by 
25 instead of 50. 

In this adjustment, it is permissible to use any strength NaOH, 
but the strength of that added to the medium must be an exact 
multiple of the strength of NaOH used in titration ; if the ratio 
is not 1 :20 proper allowances must be made. 

Method of preparing agar. 

The important point is to secure an agar of the correct re- 
action and composition which contains no troublesome precipi- 
tates. Methods of cooking and filtering to accomplish this vary 
with the ingredients used. Those suggested below have been 
found satisfactory in practical use ; but other methods securing 
the same results are allowed. White of egg, however, must not be 
used for clarification. 

The finished medium may be tubed or bottled, placing 10 cc. 
in each tube or 55 cc. (enough for five plates) in each bottle. 



•Prepared by Hynson, Wescott & Dunning, Baltimore, Md 



504 Bacteriological Tests and Cultures 

Sterilization shall be accomplished by heating in the autoclave 
for 20 minutes after the pressure reaches 15 lbs. ; or after the agar 
is completely melted, heat in flowing steam on three successive 
days for 20 minutes each day. 

All glassware and all apparatus such as kettles, funnels and 
filtration flasks, must be kept scrupulously clean by running hot 
water over or through them after use before the agar has had 
time to harden. There is danger otherwise of dried particles of 
agar chipping off and giving rise to sediment in future batches 
of agar which in the poured plates may be mistaken for colonies. 

Procedure No. 1. Mix all of the ingredients together cold. 
Heat in an autoclave at 15 lbs. pressure for 40 to 90 minutes 
according to the quantity of medium being made in each batch. 
Allow the autoclave to cool very slowly so as not to disturb the 
sediment. Decant through a cotton filter taking care not to pour 
the sediments on the cotton until the bulk of the liquid has passed 
through. 

This simple procedure with certain brands of peptone and 
grades of agar gives excellent results. 

Procedure No. 2. Where large quantities of agar are to be 
prepared the following procedure has been found useful. Pre- 
pare two separate solutions : 

Mixture A. — Beef extract 0.3 per cent of total quantity of 
medium to be made. 

Peptone 0.5 per cent of total quantity of medium to be made. 

Distilled water 40 per cent of total quantity of medium to be 
made. 

Place in a kettle. Weigh kettle with contents. Heat on stove 
to boiling, and boil five minutes. If absolutely necessary to 
adjust reaction (see Reaction) do so at this point and boil again. 
Make up with hot distilled water that lost by evaporation. Do 
this by weight. Filter through paper or paper pulp in a Buchner 
funnel (see below). 

Mixture B. — Agar oven dried 1.2 per cent (market 1.5 per 
cent) of total quantity of medium to be made. Soak and wash 
under tap in sieve. Weigh before and after soaking to determine 
quantity of water absorbed. Distilled water 60 per cent of total 



PrKparation 01? Agar 505 

quantity of medium to be made, minus that absorbed by the agar 
during the washing. 

Mix A and B (agar not yet melted). Heat mixture over stove, 
stirring at frequent intervals until agar is entirely melted. Then 
boil and stir constantly for 20 minutes. Make up by weight 
water lost by evaporation by adding liot distilled water. Keep 
kettle of agar in chamber of flowing steam while preparing 
funnel for filtering. 

Filter through cotton until clear. For 10 liter amounts it is 
suggested that either a Sharpies centrifuge or a nine inch Buchner 
funnel with a suction pump be used. The ordinary filtration 
pump attached to a water faucet producing about 11 inches of 
vacuum gives good results. 

Prepare paper pulp by soaking scraps of ordinary filter paper 
for 36 to 48 hours in a large w4de-mouthed bottle. The paper and 
water should be in the ratio of six sheets of soft absorbent filter 
paper (20 by 20 inches) to 2^/2 liters of hot water. Moisten the 
paper and tear it into fragments about ^ to 3^ inches square. 
Shake vigorously at intervals to make the suspension fine and 
uniform. When ready to prepare the nine inch funnel, take 400 
to 500 cc. of the paper pulp and dilute it with about three liters 
of very hot water. Cut a piece of surgeon's lint (or cotton, 
flannel) to fit the bottom of the funnel exactly. Rinse the funnel 
with hot water. Place in it the lint with the fleecy side upermost. 
Pour in the hot paper pulp suspension carefully so as to cover the 
lint Avith an even layer about }i to 34 ii^cli thick. Over this lay 
a disk of filter paper. Place a four liter suction flask under the 
funnel and apply the suction to draw the water into the filtration 
flask until the pulp is firm, yet somewhat moist. The agar will 
not go through too dry a filter. 

The funnel and the paper pulp must be hot when the agar is 
poured in carefully and slowly, striking the disk of filter paper 
which prevents the breaking of the surface of the paper pulp. 
Discard the first 100 cc. of agar which come through as they con- 
taih some of the water from the pulp. 

Even in the first filtration the agar should come through very 
clear. Keep the remainder of the unfiltered agar hot in flowing 
steam while the first part is rumiing through the filter. 



506 Bactkriological Trsts and Cui^turrs 

Ordinarily the temperature of the agar in the funnel is 80° to 
85° C. but the last portions will come through well as low as 50° 
to 55° C. 

Keep the filtered agar hot in flowing steam while preparing a 
second funnel in the same way as the first. Then filter as before. 
Plating. 

For miscellaneous milk samples, the character of which is not 
known, three dilutions shall be made; 1 : 100, 1 : 1,000 and 1 : 
10,000. Where the character of the milk is known, the number 
of dilutions may be reduced. If the milk is pasteurized, certified 
or known to be fresh, and of high grade, the 1,000 and 10,000 
dilutions may be omitted. If the milk is knoAvn to be old and of 
high bacterial count, the 100 and 1,000 dilutions may be omitted, 
and dilusions in excess of 10,000 prepared. In no case shall less 
than two plates be made from each sample. Where two satis- 
factor}' plates are obtained it is advisable to count both of them. 

The water used for dilutions may be placed in dilution bottles 
(99 cc, 49.5 and 9 cc. are convenient sizes) are sterilized for one 
hour in an autoclave at 15 lbs. pressure. The bottles should be 
marked so that it can be determined that they have neither gained 
nor lost water during or subsequent to sterilization. Or, the 
water may be sterilized in bulk, if kept in a properly guarded 
container, and subsequently measured directly into the dilution 
bottles with sterilized pipettes. 

The dilution bottles should have glass or cork stoppers, or 
some other type of closing that makes shaking possible. Cotton 
plugs are a less satisfactory method of closure because a small 
portion of the dilution water will soak into the cotton.^ - 

Straight sided pipettes graduated to deliver 1 cc, are the best. 
They may be either the two mark or the one mark style. In 
either case, the errors of measurement are caused more by faulty 
calibration or by faidty manipulation of the pipettes than by the 
particular form of pipette used. In using two mark pipettes, 
great care must be taken to see that the quantities used are 
exactly 1 cc, while many one mark pipettes in use are calibrated 
to contain 1 cc. rather than to deliver 1 cc. Breakage of tips of 
the latter type of pipette also cause errors. 



Plating 507 

In making dilutions the original sample and each dilution 
bottle shall be rapidly shaken 25 times, each shake being an up 
and down excursion of about one foot (entire shaking not to take 
longer than about seven seconds). After the final dilution fill a 
pipette to the mark and allow contents to run into an empty petri 
dish, the end of the pipette touching the dish as the liquid runs 
out. If the pipettes are of the one mark style be sure that they 
are so manipulated as to deliver a full cubic centimeter. Use care 
to raise the cover only as far as necessary to insert the end of 
the pipette. 

Pipette should be placed immediately in water after using to 
make subsequent cleaning easier. 

The flasks (or test tubes) of agar shall be melted in boiling 
water or steam and after melting shall be cooled to a temperature 
of between 40 and 45° C. before using. 

Pour about 10 cc. of the melted agar in each inoculated petri 
dish, and by a gentle rotary motion thoroughly mix the agar and 
the diluted milk. As nearly as possible the same amount of agar 
should be poured into each petri dish so that the depth of agar 
will be uniform in all. If desired 10 cc. may be measured out 
from the flask with a sterile pipette. 

It is important that the plating shall be completed as rapidly 
as possible. The work should be so planned that no more than 
15 minutes shall elapse after the dilution of the milk and before 
the agar is poured into the petri dishes; and in no case shall the 
interval be allowed to exceed 20 minutes. 

After the agar has been thoroughly hardened, place the petri 
dishes in an incubator. The danger of spreaders may be reduced 
either by the use of clay tops or by inverting the plates as pre- 
ferred. 

Incubation. 

Only one period of incubation, and one temperature is regard- 
ed as standard, 48 hours at 37.5° C. Piles of plates should not be 
packed too closely together and in crowded incubators ventila- 
tion should be provided. 

Counting Plates. 

If among the different dilutions there are plates containing 
from 30 to 300 colonies these should be counted,^^ and the num- 



508 Bacterioi^ogical Tests and Cultures 

ber, multiplied by the dilution, be reported as the final count. All 
colonies on such plates should be counted, and the numbers from 
the different plates averaged. If there are no plates within these 
limits, the one that comes the nearest to 300 is to be counted. No 
plate that contains less than 20 colonies shall be counted, unless 
it happens that there are no other plates. If the number of col- 
onies on the plates to be counted are in excess of 300 per plate, a 
part of the plate may be counted and the total number estimated ; 
but such plates are admittedly overcrowded and the counts are 
less than they should be. 

Countings shall be done with a lens, and all recognizable col- 
onies included. A lens magnifying 2^ diameters (or what the 
opticians call a 3j/2 x lens) is recommended for general use. In 
case any particles visible by this method are of doubtful nature 
they should be examined with a compound microscope to deter- 
mine whether they are colonies or dirt specks. 
Common sources of error in counts. 

Agar plate "counts" per cc. are to be regarded as estimates 
of numbers rather than as exact counts, since only a portion of a 
cubic centimeter is used in preparing the plates. As such they 
are (like all estimates) subject to certain well known and recog- 
nized errors whose size can be largely controlled by the care taken 
in the analysis. Among these errors are : (a) Failure of some of 
the bacteria to grow because the incubation temperature, or the 
composition reaction of the medium, is not suitable, (b) Inac- 
curacies in measurement of the quantities used, (c) Mistakes in 
counting, recording data, computing results and the like. (4) 
Incomplete sterilization or contamination of the plates, dilution 
waters, etc. The possible errors caused by these things makes it 
highly important for all routine laboratories to follow carefully a 
standard procedure. 

Recent investigations make it clear that these largely control- 
able errors, are not likely to cause serious misconceptions of 
the accuracy of results as are the errors due to the fact that bac- 
teria in milk usually cling together in groups of from two to 
many hundreds of individuals. These groups are only partially 
broken apart by the shaking given in preparing the dilutions so 
that at best the counts from the agar plates represent the number 
of isolated individuals and groups of two or more bacteria that 



RiiPuRTiNG Results 509 

exist in the final dilution water. Thus the colony counts from 
the plates are always much smaller than the total number of bac- 
teria present. This error would not be troublesome if the groups 
were of constant average size ; but the best information available 
shows that the groups in ordinary market milk commonly vary 
in size so that they contain an average of from 2 to 6 individual 
bacteria. Some samples contain groups of even smaller size than 
this, while others, such as those bearing long chain streptococci, 
may show groups containing an average of 25 or even more in- 
dividual bacteria. The irregularity of this error (whose size is 
not indicated in any way by the appearance of the plates) should 
be kept in mind in interpreting the results obtained. 

Reports. 

Because of the fact that agar plate counts only represent a 
fraction of the total number of bacteria present, they should not 
be reported as showing the ''number of bacteria per cc." Ac- 
curately speaking the counts from agar plates give the estimated 
number of colonies that would have developed on standard agar 
per cc. of milk if an entire cubic centimeter of milk had been 
used for inoculation. Because this statement of fact is cumber- 
some, and also because a certain ratio exists in each case be- 
tween the colony count and the total number of bacteria, it has 
become a common practice to speak of the plate counts as showing 
the number of bacteria per cc. This is very confusing now that 
microscopic methods of counting have been developed which per- 
mits counts of the actual bacteria to be made. These counts 
average approximately five times the size of the counts as made 
by the standard agar plate technique. 

It is therefore recommended that all agar plate counts obtained 
by the standard technique shall not be stated in the form "2,000,- 
000 bacteria per cc." but rather as follows : "official plate count, 
2,000,000." This latter form of expression shall be considered an 
abbreviated method of saying : " a count of 2,000,000 colonies per 
cc. as obtained by standard methods." Moreover analysts shall 
be careful to avoid giving a fictitious idea of the accuracy of the 
official plate count. There is ample justification for thinking 
them sufficiently accurate to justify drawing conclusions as to 
the general quality of a given sample of milk, and when a series 



510 Bacteriological Tlsts and Cultures 

of samples from the same source are examined the average result 
may permit much more specific conclusions to be drawn with 
confidence. 

Specific data showing the actual percentage error in these 
counts has been difficult to obtain, and has only recently been 
obtained by means of comparisons made between microscopic and 
agar plate counts. The conclusions reached by Breed and Stocking 
are that the margin between two plate counts made from similar 
samples of marketed milk must be as great as one to five before it 
becomes a practical certainty that the larger count actually repre- 
sents the larger number of bacteria. 

It is, however, self evident that between any two samples the 
one having the higher count probably contains the greater num- 
ber of bacteria, and this probability can be made a practical 
certainty by the examination of a series of samples. It is there- 
fore required that a series of samples, preferably four or more, 
be examined before judgment shall be rendered as to the general 
quality of a given milk supply. Under no conditions is the 
practice sanctioned of publishing exact counts from individual 
samples as showing the quality of a given milk supply. 

All laboratories conforming to standard procedure will keep a 
record of the exact number of colonies developed on the plates 
that are counted ; but will render their reports in round numbers 
only. Never use more than two significant left hand digits in any 
report, raising the number to the next highest round number in 
any case ; but never lowering it. Those wishing to be still more 
conservative may use a form of report such as "official plate 
count less than 10,000," "official plate count between 10,000 and 
30,000," and the like. 

STANDARD METHODS OF BACTERIAL MILK ANALYSIS. 

Plating apparatus. 

For plating it is best to have a water bath in which to melt 
the media and a water jacketed water bath for keeping it at the 
required temperature ; a wire-rack which should fit both the water 
baths for holding the media tubes ; a thermometer for recording 
the temperatur(^ of the water in the water jacketed bath, a sterile 



DlI,UTlONS 511 

one c. c. pipette, sterile petri dishes and sterile dilution water in 
measured quantities. 

Dilutions. 

Ordinary potable water, sterilized may be used for dilutions. 
Occasionally spore forms are found in such water which resist 
ordinary autoclave sterilization ; in such cases distilled water may 
be used or the autoclave pressure increased. With dilution water 
in eight-ounce bottles calibrated for ninety-nine cubic centi- 
meters, all the necessary dilutions may be made. 

Short wide mouthed "Blakes" or wide mouthed French square 
bottles are more easily handled and more economical of space 
than other forms of bottles or flasks. 

Eight ounce bottles are the best, as the required amount of 
dilution water only about half fills them, leaving room for 
shaking. Long fibre, non absorbent co'tton should be used for 
plugs. It is well to use care in selecting cotton for this purpose 
to avoid short fibre or "dusty" cotton, which gives a cloud of 
lint-like particles on shaking. Bottles and tubes should be filled 
a little over the 99 c. c. and 9 e. c. marks to allow for loss during 
sterilization. 

The 'dilutions recommended are 1-10, 1-100, 1-1,000, 1- 
10.000, 1 - 100,000, and 1 - 1,000,000. 

For certified milk the 1 - 100 dilution should be used, while 
1 - 100 and 1 - 10,000 will usually be found best for market milk. 

The 1-10 dilution is prepared by shaking the milk sample 
twenty-five times and then transferring 1 c. c. of the milk to a 
test tube containing the 9 c. c. of sterile water. 

The 1 - 100 dilution is prepared in the same way, except that 
a bottle with 99 c. c. of sterile water is substituted for the test 
tube. 

The 1 -1,000 dilution is prepared by first making the 1 - 100 
dilution, shaking twenty-five times and, transferring 1 c. c. of the 
dilution to a test tube containing 9 c. c. of sterile water. 

The 1-10,000, 1-100,000, and 1,000,000 dilutions are made in 
the same manner by dilutions of 1-100, 1-1,000, and 1-10,000 
dilutions, 1 c. c. to 99 c. c. of sterile water. 

It is recommended that that dilution be used which will pro- 
duce about 200 colonies to a plate, ranging from 40 - 200 where a 
1-10 dilution exceeds this number the 1 - 100 dilution is more 



512 BacterioIvOGicaIv Tests and Cultures 

accurate, etc. The number of bacteria present may if desired, be 
approximately estimated before dilutions are made by direct 
microscopic examination of a properly prepared sediment. 
Otherwise, it is necessary to make a range of dilutions thereafter 
selecting for record the count obtained on that plate which yields 
between 40 and 200 colonies. 

Plating whole milk is unreliable, whatever quantities be used, 
since the bacteria are not so well separated as in the dilutions, 
and often, owing to the crowded conditions, only a portion of 
the bacteria present will develop into visible colonies. Moreover, 
if a cubic centimeter of the milk is used, the turbidity of the jelly 
due to the presence of the milk hides the colonies present from the 
eye. 

Porous earthenware Petri dish covers are recommended as 
superior to glass since they absorb the excess moisture. They 
also have the advantage of being cheaper and more durable than 
glass, they are easily marked with ordinary lead pencil. With 
long incubation a tendency of plates with these covers to dry 
out has been observed by some workers ; for ordinary routine 
work, however, they are perfectly satisfactory using 10 c, c. of 
media to the plate and incubating in a saturated atmosphere. 
These covers should never be washed but always thoroughly dry 
sterilized before use. 

Another method of preventing spreaders is by inverting the 
dishes and placing in the glass cover of each a strip of sterile 
filter paper moistened with one large drop of glycerine. Plates 
so treated do not dry out as quickly as with the porous tops and 
the glassware does not become scratched. 
Pipettes. 

Straight sides 1 c. c. pipettes are more easily handled than 
those with bulbs ; they may be made from ordinary 3-16 inch glass 
tubing and should be about 10 inches in length. 
Plating Technique. 

The agar after melting should be kept in the water jacketed 
water bath between 40 degrees C. for at least fifteen minutes 
before using to make sure that the agar itself has reached the 
temperature of the surrounding water. If used too warm the 
heat may destroy some of the bacteria or retard their growth. 



CoNTRor.s 513 

For routine work in cities in order to bring down the actual 
number of colonies in a plate to about the standard of two 
hundred, it is well to use a dilution of 1 - 10,000. To make this 
dilution use two bottles of sterile water each containing 99 c. c. 

Shake the first dilution twenty-five times, then with a fresh 
sterile pipette transfer 1 e. c. to the second dilution water, rinsing 
the pipette to the mark as before ; this gives a dilution of 1 - 
10,000. Shake the second dilution twenty-five times, then with a 
sterile pipette transfer 1 c. c. to the Petri dish, using care to raise 
the cover only as far as necessary to insert the end of the pipette. 

Take a tube of agar from the water bath, wipe the water from 
the outside of the tube with a piece of cloth, remove the plug, pass 
the mouth of the tube through the flame and pour the agar into the 
plate, using the same care as before to avoid exposure of the plate 
contents to the air. 

Carefully and thoroughly mix the agar and diluted milk in the 
Petri dish by a rotary motion, avoiding the formation of air 
bubbles or slopping of the agar, and after allowing the agar to 
harden for at least fifteen minutes at room temperature place the 
dish bottom down in the incubator. 

Controls. 

Plating should always be checked by controls. A blank plate 
should be made with each series of milk plates for control on the 
agar, water, air, Petri dishes, pipettes, etc. 

For control of the technique of plating, it is recommended 
that for work on "market milk" duplicate plates be made each 
day on several samples. 

"Certified milk" should always be plated in duplicate and 
where it is possible it is well to have one man's work occasionally 
checked by another. 

Unless duplicate plates show as a rule approximately the same 
count the worker should see if there is error in his technique. 

Plating should always be done in a place free from dust or 
currents of air. 

In order that colonies may have sufficient food for proper 
development 10 c. c. of agar shall be used for each plate. In 
plating a large number of samples at one time the dilution and 
transfer of diluted milk to the plated may be done for four or 
eight samples then the agar poured, one tube to each plate, then 
another eight samples diluted, etc. 



514 BactkrioIvOgical Tests and Cultures 

INCUBATION AND COUNTING. 

Two standard temperatures are recognized : 

1. 48 hour incubation at 37 degrees C. 

2. Five day incubation at 21 degress C. 

Regulations governing the number of bacteria allowable in 
milk should direct the method to be used in examination and in 
all reports, papers, etc. on the bacterial count of milk this factor 
should be explicitly stated. 

Incubators should be carefullj^ regulated. Whatever tempera- 
ture of incubation may be used it is important that the incubator 
air sliould be saturated with moisture ; this may be accomplished 
by either having a depression in the floor of the incubator filled 
with water or by setting a pan of water on one of the shelves. 
Counting. 

Expressing of results. Since minor differences in milk counts 
are within the working error of methods and are of no significance 
in practice, the following scale has been adopted for recording- 
results of market milk examination : 

Counts below 50,000 are distinguished by five thousands. 

Counts between 50,000 and 100,000 are distinguished by ten 
thousands. 

Counts between 100,000 and 500,000 are distinguished by fifty 
thousands. 

Counts between 500,000 and 5.000,000 are distinguished by 
hundred thousands. 

Counts above 5,000,000 are distinguished by millions. 

Therefore only the following figures are used in reporting : 



5,000 




400,000 


10,000 




450,000 


15,000 etc 


to 50,000 


500,000 


60,000 




600,000 


70,000 




700,000 


80,000 




800,000 


90,000 




900,000 


100,000 




1,000,000 


150,000 




1,000,000 etc. to 5,000,000 


200,000 




6,000,000 


250.000 




7,000,000 


::;00,000 




8,000,000 etc. by millions 



Microscopic Counts 515 

Counts on "Certified" or "Inspected" milk shall be expressed 
as closely as the dilution factor will allow. 

The whole number of colonies on the plate shall be counted, 
the practice of counting a fractional part being resorted to only 
in case of necessity, such as partial spreading. 

Various counting devices have been recommended by diiferent 
workers. The more simple ones, where the whole plate can be 
seen at once, are more desirable on account of there being less 
likelihood of recounting colonies. Colonies too small to be seen 
with the naked eye or with slight magnification shall not be 
considered in the count. 

(B) MICROSCOPIC COUNT OF BACTERIA^ (BREED METHOD). 

Various methods for counting bacteria in milk by microscopic 
examination have been described, but the method that is com- 
monlj^ described as a direct microscopic exajnination of a dried 
film of milk has been found to be the simplest and most reliable 
method of counting the bacteria as they exist in the milk itself. 
It is recognized in this report as a standard or official technique 
of equal standing with the colony count from agar plates where 
used for judging the quality of unpasteurized milk. 

Apparatus required. 

In addition to a microscope, microscopic slides, stains, etc., the 
only special apparatus required is a capillary pipette which dis- 
charges 1/100 cc. of milk. The most satisfactory form of pipette 
is made from a straight piece of thick walled capillary tubing 
with a bore of such a size that the single graduation mark is from 
1^ to 2^4 inches from the tip. The tip shall be blunt and of such 
a form that it will discharge the milk cleanly without running back 
on the side of the tip. Pipettes of this type are now listed by all 
of the usual supply houses. The pipettes shall be calibrated so as 
to deliver 1/100 cc, not to contain 1/100 cc. Because there are 
many inaccurately calibrated pipettes on the market, the calibra- 
tion of all pipettes shall be tested by weighing the amount of milk 
discharged on chemical balances. The weight for milk should be 
.0103 grams. 

Only a single pipette is needed in making a series of tests, 
provided this is kept clean while in use. In this kind of work 
cleanliness of glassware is more important than sterilization. 



516 Bacterioi^ogicai. Tests and Cultures 

Clean towels may be used for wiping the exterior of the pipettes 
while making the microscopic preparations, and their bores may 
be kept clean by rinsing them in clean water between each sample. 
The small amount of water left in the bore may be rinsed out in 
the milk sample under examination. This method of procedure, 
while adding a small number of bacteria to each sample, intro- 
duces only a theoretical error, tests showing that such bacteria 
cannot subsequently be detected, and make no difference in the 
final result. After use, the pipettes should be kept in a glass- 
cleaning solution, such as the commonly used mixture of sulphuric 
acid and potassium bichromate. 

Routine laboratories will find it convenient to use larger 
microscopic slides than the ordinary 1 by 3 inch slide. The 
largest slides that have been found to be conveniently examined 
with the use of a mechanical stage are cut 2 by 4^/2 inches. Such 
slides may be stored in ordinary card catalogue cases and may be 
very cheaply prepared from thin window glass or old photo- 
graphic negatives. A margin of ground or etched glass on the 
longer edges of the slide about 34 ii^ch in width allows lead 
pencil labeling. The margins may be ground with an emery 
wheel, or they may be etched with hydroflouric acid. The cost of 
these home made slides ought to not to exceed 2 to 3 cents each, 
Avhereas the similar slides listed by supply houses cost much more 
than this, A special guide plate (size 2 by 4^/2 inches) marked 
off with 16 square centimeter areas is also needed. This can be 
obtained from regular supply houses. Only one of these is needed 
as it is used as a guide plate underneath the slides on which the 
milk preparations are made. 

Preparation of films of dried milk. 

After a thorough shaking of the sample, 0.01 cc, of milk or 
cream shall be deposited upon a clean glass slide by means of the 
pipette above described. Spread the drop of milk uniformly over 
an area of one square centimeter by means of a clean, stiff needle. 
This may be most conveniently done by placing the slide upon 
the guide plate just described, or upon any other form of guide 
plate of glass or paper which is ruled in square centimeter areas. 
The marks showing through the glass serve as guides. After 
spreading, the preparation shall be dried in a warm place upon a 
level surface protected from dust. In order to prevent notice- 



Microscope; Standardization 517 

able growth, this drying must be accomplished within five to 
ten minutes ; but excessive heat must be avoided or the dr}^ films 
may crack and peel from the slide in later handling. 

After drying, the slides are to be dipped in xylol, or any other 
suitable fat solvent, for a sufficient time to remove the fat (at 
least one minute), then drained and again dried. After this, 
the slides are to be immersed in 90 per cent grain or denatured 
alcohol for one or more minutes, and then transferred to a fresh 
aqueous or carbolic acid solution of methylene blue (about 1 
per cent, exact strength unimportant) that has previously been 
tested and found to stain the bacteria satisfactorily in milk prepar- 
ations. Some methylene blue now on the market in powder form 
is very unsatisfactory in that solutions will dissolve the milk 
films, or will wash them with an even blue color in which the 
bacteria fail to show distinctly. Old or unfiltered stains are to be 
avoided as they may contain troublesome precipitates. 

The slides are to be left in the stain until overstained. They 
are then to be rinsed in water and decolorized in alcohol. The 
decolorization takes from several seconds to a minute or more, 
during which time the slide should be under observation, in order 
that the decolorization may not proceed too far. When properly 
decolorized the background of the film should show a faint blue 
tint. Poorly stained slides may be decolorized and stained with- 
out apparent injur3^ After drying, the slides may be examined 
at once, or they may be preserved indefinitely. 
Standardization of the microscope. 

The microscope used must be so adjusted that each field covers 
a certain known fraction of the area of a square centimeter. This 
adjustment is simple if a micrometer slide, ruled in hundreths of 
a millimeter, is at hand (sometimes called a stage micrometer as 
it is used under the objective on the stage of the microscope). 
The microscope should have a 1.9 mm. (1/12 inch) oil immersion 
lens, and an ocular giving approximately the field desired (for 
example a 6.4 x ocular). It sould also be fitted with a mechanical 
stage. If the large slides described above are used, this must be 
a special stage allowing a larger area of the slide to be examined 
than can be examined with the usual mechanical stage. 

To standardize the microscope, place the stage micrometer on 
the stage of the microscope, and by selection of oculars or by 



518 Bacteriological Tests and Cultures 

adjustment of the draw tube, or both, bring the diameter of the 
whole microscopic tield to .205 mm. When so adjusted, each field 
of the microscope covers an area of approximately 1/3000 cm. 
(actually 1/3028 cm). This means that the dried milk solids 
from 1/300,000 part of a cc. of milk are visible in each field of the 
microscope. Therefore if the bacteria in one field only are 
counted, the number found should be multiplied by 300^,000 to 
give the estimated number of bacteria per cc. In practice, how- 
ever, more than a single field is examined so that the number used 
for multiplication is smaller than this. 

As the microscopic examinations must be made with greater 
care where the bacteria are relatively few in number, it is required 
that, in grading low count milk, a special ocular micrometer with 
a circular ruling divided into quadrants shall be used. In using 
this micrometer, the microscope shall be so adjusted that the dia- 
meter of the circle on the eye piece micrometer shall be .146 mm. 
In this case the amount of dried milk solids examined in eacli 
field of the microscope is 1/600,000 part of a cc. of milk. The 
limitation of the examination of the slide to the central portion 
of each field, avoids using the margins of the field where definition 
is hazy, and lessens the danger of overlooking bacteria. Like- 
wise the magnification used is greater than that used where the 
whole field is examined. 

Counting and Grading' Milk. 

The number of fields of the microscope to be examined varies 
Avith the character of the milk, and with the character of the data 
desired. Experience has shown that where the purpose is primar- 
ily to detect and eliminate the worst milk from ordinary market 
milk supplies, it is entirely permissible to use the entire field of 
the microscope for examination. At least thirty representative 
fields of the microscope should be examined for each sample of 
milk. Wliere the average number of individual bacteria (not 
groups of bacteria) is less than one per field, it may be assumed 
that the milk will ordinarily give an official plate count of less 
than 60,000 per cc. Where the number is less than 100 in 30 fields 
(average of less than 3 1/3 bacteria per field) it may be assumed 
that the official plate count will be less than 200,000 per cc. 
Where less than 1000 per 30 fields (average of less than 33 1/3 



Standards 519 

per field) is may be assumed that the official plate count will not 
exceed one to two million per cc. 

Where counts are made in order to enforce stringent standards, 
as at Grade A plants^^' or as a basis for premiums on milk giving 
an official plate count of less than 10,000 per cc, the special eye- 
piece micrometer described above shall be used and the micro- 
scope so adjusted that only the central portion of each field is 
examined for counting. Where less than 5 bacteria are found in 
60 fields (average of less than 1/12 of a bacterium per field) it 
may be assumed that the milk would ordinarily give an official 
plate count of less than 10,000 per cc. The grading of milk of 
tills type must be done with especial care as persons inexperienced 
with microscopic work have been found readily to confuse ex- 
traneous objects with bacteria, in milk containing very few 
organisms. Where the number is less than 30 per 60 field 
(average of less than ^/^ a bacterium per field), it may be assumed 
that the official plate count will be less than 60,000 per cc. Where 
the number is less than 100 per 60 fields (average of less than 
1% bacteria per field), it may be assumed that the official plate 
count will be less than 200,000 per cc. Where the number is less 
than 1,000 per 60 fields (average of less than 16% bacteria per 
field), it may be assumed that the official plate count will be less 
than one to two million. 

The standards given are computed (with the exception of the 
poorest grades) on the assumption that the official plate count 
will be normally average 1/5 of the total number of individual 
bacteria present. As many cases Avill be found which diverge 
markedly from the average, it is self evident that this average 
represents only an approximation to the real conditions in any 
specific case so that in some cases the microscopic grading will be 
more severe than that based on the plate counts, and vice versa. 
There is still a lack of sufficient data from which to judge fairly 
which system of grading is the more accurate. The indications 
are, however, that where the work is done with equal skill and 
care, and the allowances indicated are made, a reasonably close 
agreement in grade will be secured^ ^. This fact is highly reassur- 
ing as to the general accuracy of both systems of grading. 

In the routine grading of milk by the microscopic method it 
is not expected that exact counts will be made. A high grade 



520 Bactrrioi^ogical Tests and Cultures 

milk will show field after field of the microscope in which no 
bacteria are seen, while a poor grade of milk will show numerous 
bacteria in every field examined. It is only where the number of 
bacteria present is close to the border line between grades that 
counts need to be made. The examination, however, must be 
sufficiently thorough to make sure of the grade as specified above. 
In order to ensure careful work in grading, it is required that 
laboratories conforming to standard procedure shall preserve 
microscopic preparations until a reasonable period has elapsed 
after the reports are rendered to the person or persons whose 
milk has been examined. It is an excellent custom occasionally 
to have the grading done by one analyst repeated by a second 
analyst, particularly in those cases where punitive actions are to 
be based on the reports made. 

Common Sources of Error in Count. 

Routine microscopic counts, like all bacterial counts, are to be 
regarded as estimates of numbers only. They cannot be made 
with absolute accuracy even with the most careful technique. 
Errors will arise from inaccuracies in measurement of the minute 
quantities of milk examined at any one time, from faulty staining 
or preparation of slides, from mistakes in observation and the like. 
These limitations, while important, are not difficult to overcome 
in sufficient measure to make microscopic grading a satisfactory 
method of controlling the quality of unpasteurized milk. As it 
is oidy in this way that counts of the bacteria themselves can 
be made, it must be recognized that accurately carried out micro- 
scopic counts of individual bacteria give the truest picture of 
the actual conditions of raw milk that can be obtained with any 
technique. 

Where there is reason to fear the presence of large numbers 
of dead organisms, as for example in pasteurized milk, it is 
improper to place reliance upon microscopic counts. Valuable 
information may, however, sometimes be obtained by making 
both plate and microscopic counts from samples of pasteurized 
milk. 

Reports. 

As only a few ordinances^" have yet been adopted in which 
both official and microscopic count standards have been given. 



Vkrification MiiTHODS 521 

the form of report used will need to be adapted to the circum- 
stances under which each laboratory is working. Specific counts 
should not be given under normal circumstances, and care should 
be taken to avoid making finer distinctions in grade than are 
justified by the accuracy of the grading. A series of samples 
should be examined in all cases before rendering judgment as 
as to the quality of any milk supply. 

VERIFICATION AND RESEARCH METHODS. 

Because of the fact that the Committee on Technique of the 
Society of American Bacteriologists has undertaken the study of 
methods of making bacterial counts for research purposes, it is 
not necessary to discuss further the use of standard methods as 
research methods. The standard methods are designed for use 
in routine analytical work and should also be used in those cases 
where investigations involving routine milk control are under 
consideration. They may also be suitable for use in other cases, 
but ordinarily will not be found to give the grade of accuracy 
expected in research work. 

There is in all routine laboratories a very important use for 
methods giving more accurate data than can be obtained from the 
use of the routine count. These may be termed verification 
methods ; and they should be used in all cases where administra- 
tive actions are taken which depend upon the analytical results^^. 

The simplest form of verification for official plate count in the 
case of raw milk is to make a count from the same sample of milk 
by direct microscopic examination, and vice versa. If the counts 
found from the second examination are such that they are readily 
understandable under the known conditions, a very large part of 
the uncertainty existing in regard to the first count is eliminated 
at once. Under other conditions it may be found advantageous 
to verify the routine plate counts by making plate counts in which 
additional dilutions, or plates are used. Likewise more careful 
microscopic counts may be obtained either by examining dupli- 
cate preparations from the same sample of milk, or by making a 
more careful examination of the original preparation than that 
made for routine purposes. 

If procedures of this sort were more common in bacteriological 
laboratories, control officials would have much firmer ground 
upon which to defend their actions in court if necessary. 



522 BACTERioLor.icAL Tests and Cultures 

DETECTION OF SPECIFIC PATHOGENS IN MILK. 

There is no part of the field of sanitary analysis of milk where 
routine laboratory methods have so failed to meet the need of the 
control official as at this point. Some notable attempts have been 
made to secure the elimination of the bacillus of bovine tuber- 
culosis from market milk supplies through routine laboratory 
examinations of milk samples ; but none have been found to be 
sufficiently practical to have been widely followed. Other 
pathogenic organisms, such as those of typhoid fever, are rarely 
sought for in milk, though methods for detecting this organism 
have been suggested." In all of these cases, it has become 
necessary to rely on elimination of the pathogens in market milk 
supplies through pasteurization, or by veterinary inspection of 
the herds, and medical supervision of dairy employees. 

Several of our important control laboratories are, however, 
using a laboratory method for the elimination of long chain 
streptococci derived from inflamed udders. Certain precautions 
must, however, be used in this case as false interpretations of 
findings are easily possible. The long chain streptococci are 
readily found by microscopic examination of dried films of milk 
or sediments from centrifuged samples of milk. Perhaps the two 
most frequently used routine methods are the Breed method 
already described, and the Stewart-Slack method described in 
detail in the first edition issued by the American Public Health 
Association. 

The use of these methods for this purpose lias shown that 
even the presence of large numbers of long chain streptococci 
may be of little significance where there has been opportunity for 
their groAvth after the milk has been drawn. Streptococci of the 
long chain type occur frequently in apparently normal udders, 
and may even occur in very large numbers where there is no 
clinical evidence of inflammation.-" Nevertheless, where samples 
of milk can be taken from individual cans as delivered within 
6 hours after milking, it has been found that it is almost invar- 
iably possible to find a cow sufifering from an inflamed udder if 
the count of individual cocci in long chains is in excess of 1,000,- 
000 per cc. Such milk usually contains leucocytes in excess of 
1,000,000 per cc. ; but this relationship is not an invariable one. 
Because of the presence of alkaline substances from blood serum, 



Comme;rciai, Application 523 

milk from cows with inflamed udders usually has a pH value 
greater than 6.8 and may also contain detectable mucin fibers.-^ 

Where milk is centrifuged and the sediment examined, even 
greater caution should be used in drawing conclusions, as the 
concentration of material may cause insignificant numbers of 
these organisms to be regarded as significant. In this connection 
it should be remembered that many entirely satisfactory butter 
starters are composed of streptococci which occur in fairly long- 
chains. These supposedly saphrophytic streptococci cannot be 
distinguished from the udder streptococci through microscopic 
examination alone. 

Under these conditions, the laboratory findings should in 
every case be confirmed by clinical examination of suspected 
herds before action is taken. 

COMMERCIAL APPLICATIONS OF BACTERIA TO DAIRY 
PRODUCTS. 
Preliminary. 

As already pointed out several types of bacteria find a most 
useful application in several branches of the dairy industry. The 
products in which they play a useful role are of great commercial 
and economic importance, and include butter, cheese and cultured 
buttermilk as the best representatives in the list. The product 
carrying the bacteria is known as the culture or the starter. In 
this chapter the term culture will be used. 

STRAIN OF BACTERIA RECOMMENDED. 

In the experiments reported in this chapter, the bacteria used 
was a strain of Streptococcus Lacticus Kruse described upon 
page 491. This is illustrated under Fig. 118, The culture has 
been propagated continuously for about four and one half years 
under ideal conditions so that as a result of this intensive breed- 
ing, all undesirable properties had been bred out, and the culture 
was one of unusual virility which yielded in practice products of 
most desirable flavor and keeping qualities. Under similar con- 
ditions, the same favorable results can be duplicated in any dairy 
plant. 

TEMPERATURE TO USE IN RIPENING. 

It is practically universally agreed that the best temperature 
for the propagation of Streptococcus Lacticus of the strain used 



524 Bactrriologicai. Tksts and Cultures 

in cultures employed in the dairy industry is 20^ C. (68° F.) 
The control of temperature during the propagation period is of 
vast influence upon the resulting culture. 

Cultures of the Bulgaricus type have an optimum temperature 
of growth of 37" C (98.6° F.). The use of this type is greatly 
upon the decline, and is but little used in commercial work. 




Fig. 118. Streptococcus Lacticus. Fhotomicrograpli from Research labora- 
tories, Telling--Bene Vernon Co. Magnified 950 Diameters. Isolated 
from Cultured Buttermilk. 

FACTORS RELATING TO THE GROWTH OF CULTURES IN 
DAIRY PRODUCTS. 

Several investigators have shown that the rate of growth of 
the organisms in a culture varies during different periods or 
phases of its life. By its life is meant a condition of environment 
in which the culture is permitted to grow without any unfavor- 
able interference. 

Buchanan^- divides the life cycle of a culture into given 
phases, each phase having a different rate of growth per organism 
than the phase next preceding it as follows : 

(1), The initial stationary phase. During this phase the bac- 
teria remain constant or nearly so. 

(2). The lag or positive growth acceleration phase. During 
this phase the average rate of growth per organism increases with 
the time. 



Reaction of Acid 525 

(3). The logarithmic growth phase. The rate of growth per 
organism in this period is constant. The organisms are dividing 
regularily, and the number of organisms are increasing in a 
geometric ratio. 

(4). The phase of negative growth acceleration. The 
average rate of growth per organism decreases during this period. 

(5). The maximum stationary phase. There is little or no 
increase or decrease in the number of organisms during this period. 

(6). The phase of accelerated death. The number of bac- 
teria decreases slowly at first, but the rate of death per organism 
gradually increases until it reaches a maximum. 

(7.) The logarithmic death phase. During this phase, the 
rate of death per organism is constant. 

Barber-^ observed that the age of the culture influenced 
the lag phase. He found that if a sub-culture was made in the 
same medium during the logarithmic period, this sub-culture does 
not go through a lag period, but continues to grow, at the same 
rate per organism as the parent culture. If the sub-culture is 
made after the logarithmic period there is a distinct lag period. 
These observations were confirmed by Penfold and by Ches- 
ney.-* 

RELATION OF ACID, DEVELOPMENT AND TIME OF 
RIPENING. 

Frohring-' conducted a series of careful experiments with 
a strain of Bacillus Streptococcus Lacticus using the 'development 
of the lactic acid in the culture as the criterion of the growth of 
the organisms. This method was selected because of the con- 
siderable errors that may result when counting bacteria by the 
plate method. Another important reason for this choice was the 
desirability of obtaining exact data regarding the relation be- 
tween time and acidity in culture growth. 

Frohring points out that this method of study gives a fairly 
good conception of the first four growth phases mentioned above, 
but that it is valueless in determining the last three. 

The results obtained by Frohring are given in Fig. 119. 

As the results in Fig. 119 indicate, the acid development is 
not in direct proportion to the time, as is commonly believed to 
be the case by many accustomed to using cviltures. The results 



526 



Bacteriologicai, Tests and Cultures 



are typical of the acid development curve produced by a fresh 
vigorous culture which is being propagated daily under optimum 
conditions which are under exact control. 15 cc. of this culture 
was added to 750 cc. of the media. 




Figr. 119. The Belation Between Time of Incubation and Acid Development 
in the Growth of Culture. 



As shown in the graph, there is scarcely any increase in 
acidity during the first four hours. From the fourth to the tenth 
hour, the increase is a gradual one. In this particular experiment 
coagulation started at the tenth hour, with a total acidity of .64 
per cent and from that point the growth was very much retarded, 
but it continued to increase until the ripening had continued for 
seventeen and a half hours, at which point it became constant 
with a total acid content of 1.00 per cent, being still of thi^i 
acidity at the end of 74 hours. 

INFLUENCE OF QUANTITY OF CULTURE ADDED TO MEDIA. 

In another series of experiments Frohring studied the influ- 
ence of the addition of varying quantities of culture to a given 
media. The cultures were fresh, vigorous ones, similar to those 
employed in the previous experiment, and these were added to a 



Quantity of Culture 



527 



good quality of pasteurized skim-milk. The results obtained 
are given in Table 93. 

TABLE 93. 

Influence of Quantity of Culture Added to Media. Acidity Gi/en Is That 

Developed in Addition to Initial Acidity, and Acid Added in Starter. 



Experi 
ment No. 



Quantit}' o 
culture add- 
ed to 750 c 
c. of media 



Per cent of 
lactic acid 
in media p 
end of 15 
hours. 



Experi- 
ment No 



Quantity o 1 
cxilture add- 
ed to 7.50 (• 
c. uf media. 



Per cent of 
lactic acid 
in media at 
end of 1 
hours. 



5 c. c. 

10 c. c. 

20 c. c. 

30 c. c. 

40 c. c. 



.89 
.91 
.92 
.93 



5 c. c. 

10 c. c. 

20 c. c. 

30 c. c. 

40 c. c. 



.94 
.90 
.94 
.99 
.97 



.70f 
.605 

I 

.xos 



Aeld isYslopeii urtnr IJ nour« Inoubatlon (at iO»C) 
In adaiUon to Ir.ltUi acUSty a-M icH adlod ir sta 



Amount of 

culture aiaad 

(C.:.) 



ic 15 20 30 io 50 



5 *o 15- 20 30 40 50 



5 10 15 ;o 30 40 50 



*^- "»■ 3 m, 



Tig. 120. Influence of Quantity of Culture Used Upon Acid Development 

in Media. 



The results of another series of experiments by Frohring are 
given in the graph under Fig. 120. 



528 



Bacteriological Tests and Cultures 



The results of the preceding experiments by Frohring indicate 
that the amount of culture added is not so important as the grow- 
ing condition of the organisms that are introduced, and their 
ability to divide, and go through the logarithmic stage of growth 
after a few hours of incubation. The determining factor in judg- 
ing the value of a culture is not the total number of organisms 
contained, but rather the number of organisms capable of prop- 
erly reproducing themselves. He has applied this knowledge in 
practice with marked success. 









ututi 
•we 




^ 


4» 0.0. 








.ao 


■ __„-.,r«-^ 


:::ri 


WO. 0. 








^^,-*— -^ " 


-t——^"P^ 








>? 




.70 ^.y"""^ 


y"' 




. 




2 


















/ *' 








i 


S' 




.60 / y 










i 




/ ^' 






; 




1 


.10 


,*0 _y^ .-" 

Hours ol inCiJbatiua 
% 2 i 4 ^ 6 7 8 9 . M J^ W 


i 
W M IS 


»6 


■ ' j 

^ 1 
— -l 



Pig-, 121. Increase in Titratable Acidity Using- 15 c.c. and 40 c.c. of Culture 

to 750 c.c. of Media. 



In the above figure it is shown that the same results are 
obtained at the end of the ripening period when only 15 cc. 
(About 2.0 per cent), or when 40 cc. (about 5.0 per cent) of 
culture are added to the media. 

In the manufacture of cultured buttermilk, cottage cheese, 
cheddar cheese, soft cheeses, margarine and butter made from 
ripened cream, or where the culture is worked directly into the 
butter, it is universally conceded that the quality and uniformity 
from day to day of the culture is of the greatest importance to 
the manufacturer who is endeavoring, to maintain a uniform 
product. 

A careful study of culture propagation reveals a great many 
factors which, when properly controlled, will insure the successful 



Time and TiiMPHRATuRe "529 

propagation of a uniform culture free from contamination. 
Under ordinary factory conditions, painstaking care may eliminate 
some of the variables. There still remains, however, many vari- 
ables over which the operator has no control. This means a 
constant risk, or hazard of meeting unfavorable conditions, and 
as a consequence, frequent off flavored or inferior products. 

TIME OF RIPENING. 

Frohring has proved that if too much time is taken for the 
ripening period, undesirable types of bacteria may gain the 
ascendency'- before the logarithmic stage of growth is reached, 
and as a result bad favors may appear in the finished product. 
This condition may exist if too small an amount of culture is 
added to the media. 

Upon the other hand, if the ripening time is too short, due to 
the addition of an excessive amount of culture, the results are also 
not satisfactory. 

In general, it can be stated that the least amount of culture 
should be added to produce a satisfactory product. No more acid 
should be added mechanically than necessary. The most practi- 
cal ripening; time is 14 hours. 

EFFECT OF HOLDING CULTURE AT VARIOUS TEMPERATURES. 

In handling cultures it is important to know the influence of 
the holding temperature upon tlie growing qualities of the culture. 
This is the determining factor in establishing the frequency of 
repropagation. This was carefully studied by Frohring, under four 
different temperature conditions. In one experiment the mother 
culture was frozen ; in a second experiment it was kept in ice 
water; in a third experiment it was kept at 45° F., and in a 
fourth experiment at 68° F. Inoculations from each of the 
above mother cultures were made in pasteurized skim-milk media 
upon successive days as indicated. In each test 15 cc. of the 
four respective cultures were inoculated into 750 cc. of skim-milk, 
and these sub-culture were incubated for 15^^ hours at 68° F. 
The titratable acidity was determined at the end of each incuba- 



530 



Bacteriological Tests and Cultures 



tion period, and this was used as the criterion of the growing 
qualities of the respective cultures. 

The results in the following chart show plainly how the grow- 
ing qualities of a culture are influenced by the temperature at 
which it is kept following the end of the incubation period. The 
culture that was frozen lost little of its reproductive powers up to 
eight days. After that it deteriorated rapidly, and at the end of 
eleven days it had practically lost its ability to grow. The fol- 
lowing table gives the main conclusions that can be derived from 
this experiment. 



ACIDITY OF SUBCULTURE OBTAINED FROM MOTHER 
CULTURE, THE L/\TTER BEING KEPT AT TEMPERATURES 
INDICATED DURING EXPERIMENT. 

HOURS OF INCUBATION-Isi HOURS AT eb'F 
AMOUNT OF CULTURE ADDED- IS CC. TO 750 CO. 6KIM-MILK 




TIME IN PAYS 



Tig. 122. Influence of Holding Temperatures of Cultures Upon the Growing 
Qualities of the Same. 



Apparatus for Propagating Culturks 



531 



TABLE 94. 

Summary of Experiment to Deteimine Influence of Holding Temperature 
Upon the Growing Qualities of Cultures. 



T e m p e rature at 
which cultures 
were held. 


Number of days 
held at tempera- 
tures indicated 
before growing 
qualities began 
to deteriorate. 


Number of days 
held at tempera- 
tures indicated 
when cultures 
had pi-actically 
lost their ability 
to grow. 


Number of days 
during which 
cultures can be 
kept at temper- 
atures indicated 
before requiring 
repropagation of 
culture. 


Frozen 


8 


12 


5 






Ice water, 32° F. . 


11 


15 


7 


45° F.. 


7 


8 


2 


68 F°.. 


2 


7 


1 



The results given in the above described experiment show 
plainl}^ the great influence of holding temperature upon the grow- 
ing qualities of cultures. The best results are obtained where 
the cultures are kept in ice water. In practice even when the 
cultures are kept in ice water, a limit of one week should not be 
exceeded, before repropagating the culture. When held between 
32 and 45° F. the limit should not exceed two days. At 
temperatures above 45° F. the deterioration of the culture is so 
rapid, as to render such temperatures impractical for holding 
purposes. 

APPARATUS DESIGNED TO PROPAGATE PURE CULTURES. 

To W. 0. Frohring, Director of Laboratories of the Telling- 
Belle Vernon Co., belongs the credit for the origin and develop- 
ment of the Mojonnier Culture Controller. The principles under- 
lying the construction and operation of this apparatus were 
established by him in a large plant devoted to the manufacture 
of numerous dairy products requiring the use of pure cultures, 
the principal being commercial buttermilk, cottage cheese and 
butter. 

The Mojonnier Culture Controller illustrated under Fig. 123 
places the propagation of pure cultures upon a scientific basis. It 
is a highly specialized apparatus by means of which all variables 
are eliminated. It makes the propagation of the culture a 



532 



Bacteriological Tlsts and Cultures 



definite and a simple operation. It eliminates the necessity of 
obtaining cultures from outside sources. Its great advantage is 
the fact that it insures a uniform culture from day to day. This 
in turn is reflected in the uniformity of the finished product, 
since a good culture is the starting point of a good finished 
product. 




Pig-. 123. Mojonnier Culture Controller, Model "B" 



DESCRIPTION OF MOJONNIER CULTURE CONTROLLER. 

It consists of two chambers. The chamber to the right is 
intended to hold a sufficient supply of ice to maintain a tempera- 
ture of 68° F. in the other chamber, over a considerable period 
of time. Or it is also furnished so that it can be used inter- 
changeably for ice, or for circulating brine through the lead coils 
placed in the chamber. Either method works out satisfactorily 
in practice, and the choice is governed by the conditions prevail- 



The MojoNNiER Culture Controller 



533 



ing at the plant where the apparatus is to be used. The ice 
chamber also frequently serves as a refrigerator for holding the 
cultures after the same have been incubated. 




Tig. 124. Cross Section, Mojonnier Culture Controller. 

A — Incubator Chamber. B — Refrigerator Chamber. C — Relay and Pan 
Motor Housing. 

With electro-thermostatic control showing- cross section of the two com- 
partments. The arrows indicate complete circulation of air in the chambers. 
The relay cabinet on side insures positive and continuous control of tempera- 
tures in the incubation chambers. 



The chamber to the left is the incubating chamber. It can be 
used for the propagation of both Bacillus Lacticus which is 
incubated at 68° F., and of Bacillus Bulgaricus which is incubated 
at 98.6^ F. When desired to change from one culture to the 
other, all that is necessary is to change the thermostat inside the 
chamber using the one that gives the proper temperature 
control. The incubating chamber is provided with a fan oper- 
ated by means of a motor, thus insuring uniform temperature 
in all parts of the chamber. It is fitted with heating elements of 
the proper design. Ports fitted with shutters connecting with the 
ice chamber makes possible the necessary air circulation. The 
temperature control is based upon the use of a mercury thermo- 



534 



Bacteriological Tests and Cultures 



stat operating with special design of relay. Only 1/100 of an 
ampere passes through the thermostat thus eliminating all oxida- 
tion at points of contact. The operation is entirely automatic. 
The ice chamber has a capacity of about 400 pounds of ice. 
The incubating chamber has a capacity of 54 quarts or bottles or 
125^ gallons of milk, in one model, and 17 quarts or 41^ gallons 
in another model. 

STERILIZER USED IN CONNECTION WITH THE MOJONNIER 
CULTURE CONTROLLER. 



The sterilizer that was 
especially designed for use in 
connection with the Mojon- 
nier Culture Controller is 
illustrated under Fig. 125. 
The quart culture jars can be 
both heated and cooled to the 
proper temperatures in it, 
and the entire design and 
arrangement is such as to 
facilitate this important op- 
•. eration. 

How to propagate cultures 
using the Mojonnier Culture 
Controller. 

rig-. 125. SterUizer Recommended to Be The SUCCeSSlVC StcpS in the 

Used in Connection with the Mojonnier propagation of pure Cultures 
Culture Controller. 

need to be well understood, 
and the details of each step closely followed from day to day no 
matter how trivial the same may seem, otherwise satisfactory 
results cannot be obtained. 

The kind of media to use. 

Although the pure culture organisms will grow in a variety 
of different mediums, such as nutrient broth, gelatin, etc., the 
preponderance of evidence is in favor of the use of skim-milk 
of first class quality. Whole milk is the next best, but should not 




Preparation of AIedia 535 

be used if skim-milk is obtainable. If whole milk is to be used, 
remove as much cream as possible by the gravity method. Skim- 
milk produced by centrifugal or gravity methods, — the former 
method of course, being preferable. It is needless to say that 
this should be as fresh as possible, and of the best quality obtain- 
able. It is desirable that as little change as possible should have 
taken place in the milk, not on account of any danger from the 
organisms present, as the media is subsequently pasteurized, but 
on account of undesirable by-products that may be present vs^here 
change has occurred as a result of chemical action wrought by 
bacteria differing from pure culture varieties. It is possible to 
have such chemical changes take place in milk which may later 
tend to have an inhibiting effect upon the growth of the Bacillus 
Lacticus organisms. The use of skim-milk of good quality, 
promptly sterilized, will eliminate the above factor. 

STERILIZATION AND PREPARATION OF MEDIA. 

Probably the most common method of sterilization in labora- 
tories is by means of steam pressure of 15 to 20 pounds for 
fifteen minutes to one half hour, in an autoclave. This method 
is a quick and positive means of sterilization, however, it has a 
decided disadvantage as a method of sterilizing milk used in 
propagating cultures. It is practically impossible to sterilize 
under pressure without causing an appreciable change in the 
milk. The most important change is probably in the )milk 
sugar, which is caramelized more or less by the high temperatvire 
used during sterilization. In the metabolism of the bacteria 
during the process of growth, some of the milk sugar is changed 
to lactic acid. It would seem reasonable to conclude that any 
decided change in the milk sugar would be undesirable. This 
proves in actual practice to be the case, and can be easily 
demonstrated. At the same time a change takes place in the 
casein. This is not definitely understood at present, but all the 
evidence is in favor of the view that certain chemical changes 
take place in the casein molecule. While this is probably not 
so important from the standpoint of food material of the bacteria, 
yet it is very undesirable as it makes it next to impossible to 
judge accurately the degree of ripening by the extent to which 
the milk is curdled. Two possible explanations of the chemical 



536 BacterioIvOGical Tf:sts and Cultures 

changes in casein due to heating are advanced. One theory is 
that part of the calcium is split off from the casein molecule. An- 
other theory is that the casein is partly dehydrated. The more 
change that has taken place in the casein the less it will be 
curdled, by the same amount of acid. A culture may thus be 
over ripe, and at the same time not set in a good firm curd. Due 
to these physical changes, the end point in ripening may be 
easily misjudged. Overheating of the milk .probably causes 
changes in the mineral salts, and it exerts an unfavorable effect 
upon water soluble C vitamine, all of which may have some 
possible bearing upon culture development. 

By means of intermittent sterilization, the milk is heated 
to a temperature above 212° F. Heating for one hour at 212° F. 
will destroy almost all organisms, except the spore formers. By 
allowing the milk to incubate between the heatings, the spores 
are given a chance to vegetate, and by the end of the heating on 
the third day they are nearly all destroyed, being caught while 
in the vegetative or non-resistant state. This method of steriliza- 
tion has not the disadvantage of the one previously mentioned, 
and the heat may be applied uniformly. However, it has the 
disadvantage in time, and is not very practical for this purpose. 
Where the milk used as media is of first class quality, it will be 
found that heating to 170" F. for one and one half hours in the 
sterilizer described under Fig. 125, will be sufficient to insure 
good results. At the end of the heating period, cold water is to 
be turned into the sterilizer to displace the hot water, and the 
milk in the jars cooled as promptly as possible to about 68° F. 
It must be remembered that this cannot be called sterilization but 
rather high temperature pasteurization, and the results may not 
be an absolutely sterile media. However, where the milk is of 
first class quality the organisms left will be insignificant numeri- 
cally, and of a type that will cause no trouble in the culture if 
it is inoculated the same day. 

CULTURE JARS USED— HOW TREATED. 

Several types of culture jars can be successfully used. In 
some cases pint size or quart size milk bottles, sealed with a 
paper cap, are very successfully employed. Experience has 
proved that culture jars such as illustrated under Fig. 126 are 



Prockdurr 



537 



the most satisfactory to use. Both the jars and the covers can be 
successfully sterilized by inverting the same in the sterilizer 
described in this chapter (See Fig. 125) and heating with flow- 
ing steam. 

To seal the jars, parchment paper is placed 
between the lid and the jar. This paper can itself 
be sterilized by dipping it in hot paraffine, grain 
aleoliol, or sodium hypochlorite. 

FILLING THE JARS \YITH SKIM-MILK. 

After the jars illustrated under Fig 126 are 
thoroughly cleansed and sterilized they are 
weighed upon a balance, and for the quart size. 
750 grams of the sterilized skim-milk are added to 
each jar from the metal percolator suspended 

Tig. 126. Type of above the balance. This is done with all the jars. 

Jars for Culture pj^^^ ^^j^^ -^ ^^^ ^^^^^^ where Only a fcw cultures 

Propagation. '' "^ 

are made daily, and they may also be used for 
the culture held over to propagate the next day's culture. 
Measuring may be done by volume if more convenient. The 
essential thing is to use a definite amount every day. Half gallon 
glass jars can frequently be used to good advantage. 




SEALING THE JARS. 

The method of sealing must accomplish the following results: 

(1). It must eliminate the possibility of bacteria getting into 
the milk after it is sterilized. 

(2). At the same time, it should not be so the air cannot 
expand without breaking the bottle while sterilizing, or form a 
vacuum when cooled. 

(3). It must protect a sterilized lip surface over which the 
culture is poured when emptying. 

(4). It must protect the lip surface while handling. 

(5). It must be air and water tight after inoculating. 

(6). It must pi'otect against molds. 

All the^e things are accomplished by using the glass jars 
illustrated above. The method of sealing is as follows : 



538 Bacterioi^ogicaIv Tests and Cur.TuRE:s 

The jars with the covers must be first thoroughly cleaned and 
sterilized in an inverted position in the sterilizer using just 
enough steam pressure to insure circulation, and kept in this posi- 
tion until ready for use. After the proper amount of milk is 
weighed or measured into the jars, two circles of parchment paper 
previously sterilized, are placed over the jar opening, and the 
cover then placed in position and loosely clamped in place. 

STERILIZING OR HIGHLY PASTEURIZING THE MILK. 

Without further delay the jars of milk are placed in the 
sterilizer, and heated for one to one and a half hours at 170° F. 
using preferably, flowing steam. This has the advantage of 
heating the jars rapidly, and of reaching with the heat, all parts 
of the joint between the lid and the jar. However, it is usually 
equally satisfactory to use hot water of the temperature indicated, 
instead of flowing steam. At the end of the heating period the 
cold water valve is opened, and the jars with their contents are 
rapidly cooled to 68° F. without removing from the sterilizer. 
The media in the jars is now ready to inoculate. The inoculation 
should be done promptly, and before the media has undegone 
a change in temperature. The method to use in inoculating the 
media immediately follows. 

PREPARATION OF CULTURE PIPETTES. 

These pipettes are especially designed with bulb for holding 
cotton, and they are of 10 cc. capacity graduated to 1 cc. all 
being as illustrated under Fig. 127. The top, which is placed 
in the mouth, should be plugged (not too tightly) with the non- 
absorbent cotton. This cotton is for the purpose of preventing 
the possibility of contamination of the culture from the mouth, 
or saliva getting into the pipette. After the pipettes are 
thoroughly cleaned and the cotton plug is inserted near the 
upper end, they are wrapped in ordinary cheap wrapping paper, 
using just enough to cover them, and fastened by twisting the 
end. While tlius wrapped, they should be sterilized either under 
steam pressure of 15 pounds for 15 minutes, or they may be 
steamed in the sterilizer under low pressure using streaming 
steam. They are kept wrapped after sterilizing and. until ready 
to use. 



Amount of CuvruRE: 



539 



HOW TO DETERMINE THE PROPER AMOUNT OF CULTURE TO 
ADD FOR A GIVEN LENGTH OF TIME OF INCUBATION. 



1 TO BE 

I PLUGGED 

>, NON-ABSORBENT 
COTTON 
THEN 
STERILIZED 



When starting out to use the Mojonnier Culture Controller, 
it is necessary to determine the amount of culture to be added 
in order to have the new culture ripened to the 
proper degree in a given length of time. This time 
should not be over 15 hours nor less than 8 hours. 
Prepare six quart jars containing 750 grams each 
of sterilized milk. After sterilizing, cooling and 
adjusting the temperature at 68° F., hold them 
at that temperature in the incubator until the 
regular time for propagating the cultures. This 
should not exceed one hour. At that time, to 
No. 1, add 3.75 grams of culture from the pipette ; 
to No. 2, 10 grams ; to No. 3, 15 grams ; to No. 4, 
20 grams; to No. 5, 25 grams, and to No. 6, 30 
grams. The bottles are then resealed. They are 
shaken up thoroughly, and placed in the incu- 
bator, and left until the time convenient to take 
them out every day. At this time they should be 
removed from the incubator, — carefully, so as not 
to break the curd, and examined. The proper 
amount of culture to use every day is the quantity 
placed in the bottle in which the milk is curdled 
with a rather tirm, jelly-like consistency without 
showing traces of whey on the top. This proportion should then 
be used and continued, unless the culture increases in strength, 
in which case the amount is reduced in proportion. 

In this connection, it must be remembered, that, although the 
amount of culture may be changed to take care of the ripening in 
the desired length of time, the temperature at which the culture is 
incubated must never be changed. This, of course, means the cul- 
tures of the same type, for the Bulgaricus type requires a higher 
temperature as Avill be explained later. Ordinarily this will be 
sufficient range to find the proper amount for ordinary cultures 
where the incubating time is about 14 hours. 

A culture of ordinary strength should require the addition of 
about 15 grams to 750 grams of sterile milk in order to coagulate 



Pig-. 127. Pipette 

for Measuringr 

Cultures Into 

Media. 



540 Bacteriological Tests and Cultures 

or ripen the new culture properly in 14 hours. If less than these 
amounts are found to be sufficient it will indicate that the culture 
is possibly a little stronger, or more active than ordinarily. Of 
course, if it is necessary to add more than this amount, it will indi- 
cate that the culture is not as vigorous as the average. After the 
right proportion has been established, the same time and amounts 
should be used regularly. In this way, an increase or decrease 
in the activity of the culture can be quickly noted. It has been 
found that wherever practical the 12-14 hour incubation using 
15 grams of culture to 750 grams of milk gives the most satis- 
factory control. 

If the culture is of a good type, it Avill gradually tend to 
increase in strength or activity, and a decrease would indicate 
that it is either an undesirable strain of Bacillus Lacticus. or 
there is some mistake being made in the method of handling. 
Prohring has proved that when cultures are given improper 
environment, they may have sufficient life and vigor to reach 
the curdling point of milk, but not sufficient to pass through the 
logarithmic phase of growth. Be sure to see that the ice con- 
tainer is filled with cracked ice each time, and that the ther- 
mometer in the incubator shows that the temperature control is 
working properly. From the relation established by the trial 
propagation described above, it is also possible to arrive at the 
proper amount of starter to add to the big starter can, or to the 
finished product to be ripened. Since the temperature in these 
subsequent operations is generally not under as exact control as in 
the culture controller, a slight diflPerence in the relation may be 
noted. However, this may easily be determined by observation 
of the first ripening. 

FINAL SEALING OF CULTURE JARS. 

After the proper amounts of culture has been added to the 
jars of milk to be incubated, the parchment paper and the glass 
top are replaced upon the jars, care being taken that the milk 
in the jar does not become contaminated. The jars are then 
tightly sealed, and the tops of the same properly dated. 

INCUBATION. 

After tlie final sealing, it is very important that each jar be 
well shaken to mix the culture with media. The jars are then 



COOI.ING THE Culture 541 

placed in the incubator which is kept in operation at 68° F. The 
ice container should be filled with block ice ; the door on the 
refrigerating chamber closed tightly; the shutter between it and 
the incubating chamber should be opened to the proper degree, 
and the fan in the incubating chamber set in operation. The 
jars should not be disturbed, or the incubator door opened until 
the time of incubation has passed, which is usually 12 to 14 hours. 

COOLING. 

After removing the jars containing the culture from the 
incubator, — being careful not to break the curd, they should be 
quickly cooled by placing in the sterilizer to which has been 
added water containing a generous amount of ice. They must be 
kept in ice water but not frozen, until ready for use. A culture 
may be all right to use after being in ice water for as long as 
one week, and sometimes even longer, but the best results are 
obtained when the cultures are used within 48 hours of ripening. 
The cultures to be used in re-propagating should be given special 
attention, and as a rule should be reinoculated at least every 
other day. They should be stored in ice water. 

When the desired length of time has intervened for incubation, 
the milk should be found coagulated to about the consistency of 
jelly, without the presence of anj^ whey. The whey indicates 
over ripeness which if continued will weaken the culture. 

Overripening of the culture is undesirable since the culture is 
carried through the phase following the logarithmic phase, after 
Avhich the culture may reach the phase of accelerated death in 
Avhich the organisms die off very rapidly. The appearancei 
occasionally of a small amount of whey on one or two cultures 
should not indicate that the ones having this whey are not all 
fit to use. however, if this continues, either the time of incubation 
should be shortened or the amount of culture added decreased, 
preferably the latter. The best way is to run another trial batch 
as described above, using the same time of incubation, and vary- 
ing the amount of culture added to each of the trial jars. At no 
time should the culture show the presence of gas forming organ- 
isms which is indicated by the presence of bubbles or "pin heads" 
in the curd. 

When ready to inoculate again, the cultures kept for this 
purpose are taken from the ice water carefully wiped dry with 



542 Bacteriological Tests and Cultures 

a clean cloth, and the same precedure carried out with the 
exception of course, of the trial incubation. It is always a good 
plan to have one extra culture which may be left in the ice 
container in case of an accident to the growing culture such as 
the power being turned off, and the temperature going down too 
low for ripening. 

The propagation of B. Bulgaricus is conducted the same as 
described above, excepting that the thermostat in the incubating 
chamber is changed from 68 to 98.6° F, 

A BRIEF SUMMARY OF DIRECTIONS FOR OPERATING THE 
MOJONNIER CULTURE CONTROLLER. 

(1). Jars to be thoroughly cleaned and steamed. 

(2). Secure best fresh milk or skim-milk available, pref- 
erably the latter. Pour off or remove the cream so that approxi- 
mately 750 grams of skim-milk are left in the jar. Weigh off 
exactly this amount in each jar. 

(3). Place the jars containing the milk in the sterilizer, and 
heat to 190° F. for one hour, if short of time. Preferably heat to 
170° F. for one hour and a half. 

(4). Cool the skim-milk in the jars until it has a temperature 
of 68° F. 

(5). Remove the cap and inoculate with the exact amount of 
culture found necessary by previous experiment. 

(6). Replace the caps and seal the jars. Shake the jars 
thoroughly. This is very important. Jars cannot be shaken 
too much. 

(7). Place the jars in the incubator. 

(8). Turn on the fan and the thermostatic control; close 
doors tightly, and leave the jars undisturbed for 14 hours. Make 
sure that there is plenty of ice in the ice compartment. 

(9). At the end of incubating period examine the jars, and 
see that a heavy culture is produced. It should not show the 
presence of any whey on the top, or any signs of gas. 

(10). Place the jars in the ice chamber with plenty of cracked 
ice, or preferably keep it in ice water. Do not allow it to freeze. 
Culture is now ready to use. 

(11). Always keep in reserve one jar to make succeeding 
inoculations of the mother culture. 



Commercial Appucation 543 

THE APPLICATION OF PURE CULTURES TO THE 
MANUFACTURE OF BUTTERMILK. 

In the manufacture of commercial buttermilk, there are 
various essentials that must be kept under careful control if the 
desired results are to be obtained. The success of the business 
will depend upon the ability to produce buttermilk with a good 
aroma, and a good flavor; one that is free from gas, and that 
will not separate, but that will remain smooth and creamy. Such 
a result can only be obtained by the application of scientitid 
methods of control, in its manufacture. 

The factors of the greatest importance are : 

(1). The use of a culture of the desired bacteria. This can 
be obtained and maintained only if propagated under conditions 
insuring uniform temperature control. 

(2.) A proper understanding of the process underlying the 
care, propagation and application of pure cultures as related to 
the production of buttermilk. 

(3). The use of skim-milk of the proper quality, the same 
to be successively pasteurized, cooled, inoculated, propagated, 
cooled again, and finally bottled at a low temperature. Butter 
fat may, or may not be added depending upon the trade 
requirements. 

QUANTITY OF CULTURE TO USE. 

The method of determining the quantity of culture to use as 
outlined earlier in this chapter, and which method is used so 
successfully by Frohring, is especially recommended. The suc- 
cess of the method hinges upon the use of a strain of culture of 
unusual vigor due to having been propagated under ideal con- 
ditions over a large number of unbroken generations. The 
potential ripening possibilities of such a culture is much greater 
than in the case of ordinary Cultures produced under usual 
factory conditions. A culture propagated under these ideal 
conditions possesses the ability to reach and pass through the 
logarithmic stage of growth in minimum time. 

Highly satisfactory results are obtained in practice by using 
two quarts of culture propagated as described above to every 100 
gallons of skim-milk. The use of such a limited amount of culture 
effects several economies. Intermediate propagations between 



544 



Bacteriological Tests and Cultures 



the Culture Controller and the skim-milk to be inoculated can 
be entirely dispensed with. This makes it possible to propagate 
sufficient culture for relatively large amounts of buttermilk in 
the Culture Controllers only. No harm is likely to result if 
more than .50 per cent of culture is added, but the limit should 
be 2.00 per cent. When using ,50 per cent of culture great care 
must be taken to thoroughly distribute the culture in all parts of 
the skim-milk. 

WATER TO ADD TO THE SKIM-MILK. 

A good quality of skim-milk must be used. It is seldom 
possible to make a satisfactory product if the skim-milk is 
derived entirely from skim-milk powder. Fat may or may not 
be added in the form of milk, or cream, depending upon the kind 
of butter milk that it is desired to make. A high quality of 
commercial skim-butter milk is obtained when 10 per cent of 
water is added to the skim-milk before pasteurizing. The product 
thus obtained is of the viscosity usually demanded. 




Fig*. 128. Buttermilk Machine. 

Courtesy Creamery Package Manufacturing Co. 



HOW TO PASTEURIZE, INOCULATE AND INCUBATE THE 

SKIM-MILK. 

The skim-milk obtained as above is heated in a suitable butter 
milk vat ; either tinned copper or glass enameled, to 190° F., held 
at this temperature for one hour, and cooled promptly by means 
of both well water and ice water, or brine to about 70^ F. Equally 



Adding Culture to Skim-Milk 545 

satisfactory results are obtained if the skim-milk is heated to 
170° F. for one hour and a half and then promptly cooled sai 
described. 




Figf. 129. Buttermilk Machine. 

Courtesy J. G. Cherry Co. 



At this point the culture is added at the rate of two quarts 
to every 100 gallons. This refers to the culture propagated in 
the Mojonnier Culture Controller by the use of methods de- 
scribed in this chapter. The use of so little culture could not 
be advocated if the culture is obtained from different sources. 
The mixture is now thoroughly agitated for half an hour, and the 
cooling is continued to 68° F. The agitation is now stopped, 
and the milk in the vat held at 68° F. without agitating it, for 
about 14 hours. In practice the best plan is to so prepare the 
skim-milk that the pure culture can be added to it at about 
5 p. m. At 7 a. m. the batch is then completely incubated, 
provided the proper method was used throughout. If the milk 
is propagated below GS^ F. a bitter flavor may develop, and if 
over 68° F. gassy fermentation may result. In summer the 
incubation should be started when the milk is a little under, 
and in winter a little over 68° F. This is of course, on account 
of the tendency of the milk to go to a temperature approaching 
room temperature. The critical point at the end of the ripening 
process is the point where whey begins to appear upon the top 



546 



Bacterioi^ogicai, Tksts and Cuwures 



of the milk. When the ripening is properly completed the curd 
will break clear and sharp when a spoon is inserted into the 
coagulated mass. The acidity at this point will be about .70 per 
cent. 




Pig-. 130. Pf audler Buttermilk Tank. 

Courtesy The Pfaudler Co. 



The agitation after ripening must not be too violent, nor 
carried on too long, as there is danger of a physical separation 
of the curd. The use of a centrifugal pump in handling the butter- 
milk should be avoided on account of its tendency to cause 
mechanical separation of the curd in the buttermilk. 

After the inoculation and agitation are complete, the butter- 
milk should be cooled immediately to at least 50° F., preferably 
under 50° F., but not under 40° F., and kept cold until delivered 
to the consumer whether in bottles or in bulk. If the buttermilk 
is cooled under 40° F., there is danger of freezing, causing ice 
crystals and subsequent dehydration of the casein which changes 
the physical properties of the product. 

All utensils must be kept clean and sterile and well tinned, 
otherwise bad flavors may be introduced into the product. 



1 



BuLGARicus Cultures 547 

HOW BULGARICUS CULTURES ARE USED. 

Bulgariciis cultures are added for the purpose of giving to the 
buttermilk a characteristic sharp flavor, and particularly for 
advertising purposes in order to call the product Bulgarian 
buttermilk. Equally good results are obtained without using 
any Bugaricus culture, and its use is largely upon the decline. 




Fig*. 131. ButteTinilk Machine. 

Courtesy Davis-Watkins Dairymen's Mfg. Co. 



HOW TO PREVENT WHEYING-OFF, OR SEPARATION IN 
BUTTERMILK. 

It sometimes happens that the coagulated constituents in 
buttermilk Avill settle slightly upon standing, either in bottles 
or in cans, after the incubation and the cooling of the product 
have been completed. This will cause the appearance of a small 
layer of whey upon the top of the container. Sometimes this 
defect is objectionable, but as a rule by simple agitation the 
product can all be remixed. Inasmuch as this defect has no 
effect upon the flavor, remixing restores the buttermilk to its 
original condition. This defect sometimes occurs in the opposite 



548 Bactkriological Tests and Cultures 

direction than as indicated above, — namely the water appears 
upon the bottom instead of upon the top of the container. Butter- 
milk containing no fat, or but little fat generally wheys off upon 
the top. That containing much fat wheys off upon the bottom. 
The difference is due to the relative density of the curd, in the 
two cases. Buttermilk in which the curd contains the proper 
amount of fat to balance the specific gravity of the milk serum 
obviously will not whey-off so readily. This relation at the 
present time is not well established. 

The exact cause of wheying-off is not clearl,y understood at 
this time. The two most important factors causing this defect 
are over-ripening and insufficient cooling after incubating. Other 
important factors are the use of too much starter, the use of 
skim-milk of inferior quality, the use of skim-milk containing 
too much fat, and too high holding temperatures. 

This emphasizes the importance of proper incubation as already 
described, and of prompt cooling at the close of the incubation 
period to at least 50^ F., and keeping the buttermilk at this low 
temperature until used. Likewise only skim-milk with a low fat 
content, of good flavor, and of good quality should be used. 

THE APPLICATION OF PURE CULTURES IN THE 
MANUFACTURE OF ICE CREAM. 

A new use for pure cultures that promises well, is in the 
manufacture of ice cream. Such a culture, imparts to ice cream 
a sharp, pleasing flavor; it gives increased viscosity to the mix, 
and it inhibits the growth of certain bacteria that cause bad 
flavors. This is a comparatively new application for pure 
cultures, and much remains to be learned upon this subject. 

THE APPLICATION OF PURE CULTURES IN THE 
MANUFACTURE OF COTTAGE CHEESE. 

The manufacture of cottage cheese is in many respects similar 
to the manufacture of buttermilk. The pure culture is added, 
in the same amounts as when manufacturing buttermilk ; the 
propagation is continued at 68 '^ F. for about 14 hours, or until 
the titratable acidity amounts to about .8 per cent. The coagu- 
lated milk is now gently heated to about 95° F., taking thirty 
to forty minutes, and the liberated whey is drained off. The 



Usii 01' CuivTUREis IN Cheese: 349 

process of manufacture is then continued as usual, and is 
subject to several modifications that influence the composition, 
and also the physical properties of the product. 

The yield of cottage cheese ranges from 15 to 22 pounds per 
100 pounds of skim-milk depending upon the composition of the 
skim-milk used, and the methods of manufacture employed. The 
total solids vary between quite wide limits, ranging from 
20 per cent to 30 per cent. By using more scientific methods of 
control a product more uniform in composition can be manu- 
factured. The reader is especially referred to the works of Hall, 
Van Slyke and Hart-^ and Stocking'-^ for more detailed informa- 
tion upon this subject. 

THE APPLICATION OF PURE CULTURES IN THE MANUFACTURE 
OF BAKERS' CHEESE AND POT CHEESE. 

These are soft cheeses and the same are fully described b}^ 
Stocking.-^ 

In the case of bakers' cheese. Stocking recommends the use 
of from 1 to 3 pounds of culture for every 1000 pounds of milk. 
Likewise the addition of from % to 3^ ounce of rennet dissolved 
in water in the proportion of one part of rennet to forty parts of 
water. The incubating period is from twelve to fifteen hours, at 
a temperature of 75" F. The titratable acidity is then about .45 
to .50 per cent. The curd is separated without heating. 

In the case of pot cheese, Stocking recommends the use of 
from .50 to 5.00 per cent of culture. The skim-milk from the 
separators is cooled to about 80° F. before adding the culture. 
The separation of the curd is hastened by heating slightly, before 
removing the whey. 

The curd from either bakers' cheese or pot cheese can be used 
to make cottage cheese. 

THE APPLICATION OF PURE CULTURES IN THE MANUFACTURE 
OF CHEDDAR CHEESE. 

The principle underlying the manufacture of all kinds of 
cheese is based upon condensing certain of the milk solids by 
separating the same from the water and certain other solids 
contained in the milk. 

If properly used pure cultures may be of very great value in 
the manufacturing of either American Cheddar Cheese or of 



550 BacteriologicaIv Tests and Cultures 

many other types of cheese. The pure culture inhibits the growth 
of undesirable bacteria and hastens the proper ripening of the 
sweet milk. Only the best and purest culture should be used. 
The presence of undesirable bacteria may later cause serious 
defects in the cheese. 

According to Stocking, "ordinarily from 2^ to 5 per cent of 
culture will be sufficient to give the desired results." The 
growing power of the culture is no doubt a large factor in 
determining the quantity to use. 

The use of pure culture in cheese making helps to develop 
sufficient acidity to make it unnecessary for the curd to remain 
in the whey longer than is desired for the best results. The 
proper degree will usually be shown by an acid test of .19 to .21 
per cent. At this point both color — if any is desired, 'and rennet 
or pepsin are added. 

The principles enumerated for making cultured buttermilk 
can be applied with marked advantage in the manufacture of 
cottage cheese. This applies particularly to the advantages 
derived from pasteiTrizing the milk before adding the culture, 
the quantity of culture to use, and the temperature to employ. 

THE APPLICATION OF PURE CULTURES IN THE 
MANUFACTURE OF RUTTER. 

One of the most important applications of pure cultures is 
in the butter industry. A good quality of culture inhibits the 
growth of bacteria that may cause the development of bad flavors 
in the butter, and it in itself helps to insure a good flavor in the 
finished product. These advantages are especially apparent in 
the case of butter that is held for some time before being 
consumed. 

Through the courtesy of the Telling-Belle Vernon Co.-^ 
we give outline of method used by them in applying cultures in 
making butter. 

In the case of cream that is to be churned the day that it is 
received, the cream is neutralized to about .16 to .18 per cent of 
acid. The neutralizer is added after the cream has been cooled 
from pasteurizing temperature to a temperature of about 90° F. 
Great care is taken to mix the neutralizer properly with the 



Use op Cultures in Butter 551 

cream. The reader is especially referred to Hunziker-^ for 
detailed information regarding the best methods of neutralizing 
cream. After neutralizing about ten per cent of pure culture is 
added, and the cream is cooled immediately to 48 to 52° F. 
It is held at this temperature for 3 to 4 hours, at which time the 
acidity is about .23 to .24 per cent, and the cream is then churned. 

In the case of cream that is to be held over night, the pro- 
cedure is slightly different than that outlined above. After 
pasteurizing the cream is cooled from pasteurizing temperatures 
to about 90- F. The cream is now neutralized carefully to a 
final acid content of .10 per cent. The cream is then cooled to 
52° F., and about 7 per cent of pure culture is added. The cream 
is held for about 12 hours, at the end of which time the acidity has 
reached about .30 per cent. The cream is now churned, and it 
yields a high quality of butter. The cream is held over night 
as described above, whenever this is possible. 

REFERENCES. 

1 Melick, Chas. W. Dairy Laboratory Guide, p. 79, D. Van Nostrand Co. 
1907. 

2 Wilcox, E. V. Production and Inspection of Milli. 1912 Hawaii Agri. 
Sta. Bui. U. S. Dept. of Agri. 

3, < Duckwall, E. W. Canning and Preserving, p. 365, plate 122. 

6 Committee on Standard Methods for the Bacteriological Examination of 
Milk. Report, 3rd ed., American Public Health Association, 1921. 

" Committee on Standard Methods of Bacteriological Analysis of Milk. 
Report. Amer. Jour. Pub. Health, 6, 1315 — 1326, 1916. 

Committee on Bacterial Milk Analyses. Report of Progress. Amer. Jour. 
Pub. Hygiene, 4, 425 — 435, 1908. 

Slack, Francis H. Some observations on the bacterial examination of 
milk. Amer. Jour. Pub. Health, 7, 690 — 697, 1917. 

Berry, Jane L. Studies of laboratory media. Collected Studies, Bur. 
Laboratories, N. Y. City. S, 288 — 293, 1915. 

Sherman, J. M. The advantages of a carbohydrate medium in the routine 
bacteriological examination of milk. Jour. Bact., 1, 481 — 488, 1916. 

Conn, H. W. Standards for determining the purity of milk. The limit of 
error in bacteriological milk analyses. U. S. Pub. Health Service, Pub. Health 
Repts., 30, 2349 — 2395, 1915. 

Committee on Standard Methods for the Bacterial Examination of Milk. 
Report. Amer. Jour. Pub. Hygiene, 6, 315 — 345, 1910. 

Brew, J. D. and Dotterrer, W. D. The number of bacteria in milk. 
N. Y. Agr. Exp. Sta., Bull. 439, 1917. 

Breed, R. S. and Stocking, W. A. The accuracy of bacterial counts from 
milk samples. N. Y. Agr. Exp. Sta., Tech. Bull. 75, 1920. 

' Breed, R. S. and Brew, J. D. Counting bacteria by means of the micro- 
scope. N. Y. Agr. Exp. Sta., Tech. Bull. 49, 1916. 



552 Bacteriological Tlsts and Cultures 

REFERENCES. 

Werner, Percv. Plan for control of milk supplies in small cities. Jour. 
Dairy ScL. 1. 284"— 289, 1917. 

8 Committee on Standard Methods for the Examination of Water and 
Sewage. Report, 4th ed., 115 pp., American Public Health Assn. 1920. 

» Sorensen, S. P. L. Ztschr. Biochem., 21. 131, 201, 1909; Ergebn. Physiol., 
12, 393. 1912. 

Clai'k, W. M. and Lubs, H. A. The color i metric determination of hydrogen 
ion concentration and its applications in bacteriology. Jour. Bact., 2, 1 — 34, 
109 — 136, 191 — 236, 1917. 

Clark, W. M. The determination of hydrogen ions. Baltimore, 1920. 

lo Barnett, G. D. and Chapman, H. S. Colorimetric determination of re- 
action of bacteriologic mediums and other fluids. Jour. Amer. Med. Ass., 70, 
1062 — 1063, 1918. 

" Medalla, Tj. S. "Color standaj-ds" for the colorimetric measurement 
of H-ion concentration pH 1.2 to pH 9.8. Jour. Bact., 5, 441—468, 1920. 

'=Dearstyne, R. S. A study of the effect of cotton stoppers used in dilu- 
tion blanks on the numerical bacterial count, and of other practices in the 
technique of bacteriological laboratories. Jour. Dairy Sci., 1, 512 — 516, 1918. 

13 Hill, H. W. The mathematics of the liacterial count. Amer. Jour. 
Pub. Hygiene, 4, 300—310, 1908. 

Breed, R. S. and Dotterrer, W. D. The number of colonies allowable on 
satisfactory agar plates. N. Y. Agr. Exp. Sta., Tech. Bull. 53, 1916. 

i'' American Public Health Ass'n., 370 7th Ave., New York. 1921. 

's Commission on Milk Standards. Third report. U. S. Pub. Health Serv- 
ice. Pub. Health Repts., 32, 271 — 296, 1917. See also N. Y. City and N. Y. 
State Sanitary Codes. 

16 Breed. R. S., and Brew, J. D. The control of bacteria in market milk 
by direct microscopic examination. N. Y. Agr. Exp. Sta., Bull. 443, 1917. 

1" Model ordinance, Penn. State Dept. Health. Uocal ordinances. Butler 
and Reading, Penn. 

Frost. W. D. Comparison of a rapid method of counting bacteria in milk 
with the standard plate method. Jour. Inf. Dis., 19, 273 — 287, 1916. 

Frost, W. D. Counting the living bacteria in milk. A practical test. 
Jour. Bact., 2, 567 — 583, 1917. 

^8 Tonney, F. O. Organization of control of pasteurization. Amer. Jour. 
Pub. Health, 10, 716 — ^723, 1920. 

Schroeder, M. C. Dirt sediment testing. A factor in obtaining clean 
milk. Amer. Jour. Pub. Health, 4, 50 — 64, 1914. 

Ruehle, G. L. A., and Kulp, W. L. Germ content of stable air and its 
effect upon the germ content of milk. N. Y. Agr. Exp. Sta., Bull. 409, 1915. 

Prucha. M. J., and Weeter, H. M. Germ content of milk. 1. As in- 
fluenced by the factors at the barn. 111. Agr. Exp. Sta. Bull. 199, 1917. 

Ayers, S. H., Cook, L. B., and Clemmer. P. W. The four essential factors 
in the production of milk of low bacterial content. U. S. Dept. Agr., Bull. 
642, 1918. 

Ander.son, J. F. The frequency of tubercle i)acill! in the market milk of 
the City of W'ashington, D. C. U. S. Pub. Health and Marine Hosp. Ser., Hy- 
gienic Lab., Bull. 56, 167 — 197, 1909. 

i» Jackson, D. D.. and Melia, T. W. Differential methods for detecting 
the typhoid bacillus in infected water and milk. Jour. Infect. Diseases, 6. 
194 — 204, 1909. 

-" Hastings, E. G., and Hoffman, C. Bacterial content of the milk of in- 
dividual animals. Wis. Agr. E'xp. Sta., Research Bull. 6, 1909. 



References 553 

references. 

Sherman, J. M. Studies on the production of sanitary milk. Penn. 
State Co — — Assn. Report for 1914 — 15, p. 299 — 305, 1916. 

-^ Baker, J. C, and Breed, R. S. The reaction of milk in relation to the 
presence of blood cells and of specific bacterial infections of the udder. N. Y. 
Agr. Exp. Sta., Tech. Bull 80, 1920. 

--Buchanan (Journal of Infectious Diseases, 1918, 23, p. 109). 

"3 Barber (Journal of Infectious Diseases. 1908, 5, p. 379). 

'^* Penfold (Journal of Experimental Medicine in 1916, 24, p. 387). 

Buchner, Lougard & Riedlin (Centralblath f. Bakteriol, 1887, 11, p. 1). 

-6 W. O. Frohring, Creamery and Milk Plant Monthly, 1919, Vol. 8, No. 11, 
p. 61. 

-" Hall, F. H. Van Slyke. L. I^., and Hart, E. B. The Chemistry of Cot- 
tage Cheese. N. Y. Station Bulletin 245, 1904. 

-" Stocking, W. A.' Manual of Milk Products. The McMillan Co., New 
York, 1921. 

=" Submitted by VV. O. Frohring. 

-* Hunziker, O. F. The Butter Industry. La Grange, Illinois. 



CHAPTER XVII 

ANALYSIS AND MISCELLANEOUS TESTS 
OF DAIRY PRODUCTS 

Methods for determining the percentages of fat and solids in 
dairy products are given in Chapters III, VII, VIII. This 
chapter contains methods for determining the percentages of 
other constituents of milk and its products and various tests of 
value in the dairy industr3^ 




Pigr. 132. Specify Gravity ChainomatJc Balance. 

Courtes^■ Christian Becker Co 



SPECIFIC GRAVITY DETERMINATIONS. 

Equal volumes of the same, or of different milk products, 
usually do not have equal weights. This is due both to difference 
in the quantity of solid matter present and to dift'erences in the 
density of the various components of the solid matter. 

[554] 



Specific Gravity 555 

In the metric system the unit of volume is the cubic centi- 
meter, and the unit of weight is the gram. 

A mass of one gram of water at its temperature of greatest 
density (4°C.) has a volume of 1 cubic centimeter, and the specific 
gravity of a substance is the weight of one cubic centimeter ex- 
pressed in grams. Therefore, it follows that the specific gravity 
of water at 4°C. equals 1. The specific gravity of any other 
liquid, or of a solid, may be obtained by dividing the weight of any 
volume of it by the weight of an equal volume of water. 

When the temperature of water changes in either direction 
from 4°C. the volume expands and its specific gravity decreases. 
In practice, however, it is customary to make specific gravity 
determinations at 15.55° C. (60° F.) and to assume that water at 
that temperature has a specific gravity of 1. 

The specific gravity of liquids is most accurately determined 
by using a specific gravity bottle, and a delicate chemical balance. 
The best form of specific gravity bottle is fitted with a ther- 
mometer that also serves as a ground glass stopper, the bulb of 
the thermometer extending down into the center of the bod}^ of 
the bottle. A side arm with capillary tube opening and extend- 
ing upward a short distance from the shoulder permits the bottle 
to be filled completely. 

Before making a determination the bottle must 
be thoroughly cleaned, dried, and cooled to the 
temperature to be used in the determination, until 
its weight is constant. It is then weighed ac- 
curately on the chemical balance and the weight 
is recorded. The bottle is then filled with water 
and brought to the temperature it had when it 
was first weighed. The bottle is wiped dry, 
Pigr. 133. Specific Weighed and the weight recorded. The exact 
Courtesy Arthur temperature of the water in the bottle when the 
H. Thomas Co. weighing is made should be noted. 

The bottle is then emptied, rinsed free of water with some of the 
liquid the specific gravity of which is to be determined, and 
finally filled with the liquid, wiped dry and weighed. The 
weight of the liquid divided by the weight of the water gives the 
specific gravity of the liquid. If milk is the liquid under observa- 





556 Analysis of Dairy Products 

tion, great care must be taken to have it thoroughly mixed before 
rinsing and filling the bottle. 

A Sprengel Tube may be used in place of 
a specific gravity bottle. It is a U shaped 
glass tube, holding about 15 cc, the free 
ends being drawn to narrow capillaries and 
bent outward at right angles. Ground glass 
caps are fitted to the free ends and a line to 
be used in exact adjustment of the liquid, is 
etched on one of the capillary tubes. ^.^ ^^^ sprengei Tube. 

In determining the specific gravity of ^,.^,,^1- h. Thomas co. 
milk the weight of the empty dry tube is 

accurately determined. The tube is then filled with water and 
weighed again after bringing its contents to the desired tempera- 
ture by immersing the tube in water the temperature of which 
is controlled at 15.5° or 20° C. as desired. The operation is then 
repeated placing the milk in the tube in place of water. Divide 
the weight of the milk by the weight of the water to obtain the 
specific gravity. 

The Westphal balance is an instrument devised especially for 
the purpose of making specific gravity determinations of liquids. 
It consists of a perpendicular rod supporting a beam that has a 
glass plummet suspended at one end and a pointer attached to 
the other. When the plummet is suspended in the air the pointer 
indicates zero. When the plummet is immersed in a liquid its 
weight is decreased in amount equal to that of the liquid dis- 
placed. The arm carrying the plummet is provided with notches 
and respective riders which indicate definite weights. The riders 
are added until the loss of weight due to the displaced liquid is 
overcome and the pointer again rests at zero. The sum of the 
weights represented by the riders used equals the weight of the 
liquid displaced. The weight of the liquid displaced, divided by 
the weight of water displaced when determined in a like manner, 
gives the specific gravity of the liquid. A single weight is pro- 
vided with the instrument which brings the pointer to zero when 
the plummet is suspended in water. The temperature of the 



SpKcific Gravity of Milk 



557 




liquid aud the water should be the same (15.55° C.) when the 
determination is made. 

Determining the specific gravity of 
milk by means of lactometers: — Hy- 
drometers are instruments used for the 
purpose of determining the specific 
gravity of liquids. They consist of hol- 
low cylindrical shaped bodies of glass 
weighted at one end with shot or 
mercury and drawn out to a long nar- 
roAv stem at the other end. The weight 
is added to make the instrument take 
a perpendicular position when it is 
floated in a liquid. The stem contains 
a scale that indicates the specific grav- 
ity of the liquid. In the better form 
Tig. 135. westphai Balance. ^^ instrument the bulb of a thermome- 

Courtesy Arthur H. Thomas Co. 

ter is sealed in the lower end, the stem 
of the thermometer extending up through the hollow body and 
the thermometer scale appearing in the stem of the hydrometer 
above, or on the side opposite the hydrometer scale. 

Lactometers are forms of hydrometers made for the purpose 
of determining the specific gravity of milk. While the results ob- 
tained by their use are not quite as accurate as those obtained by 
means of a delicate balance, they enable an operator to make a 
large number of specific gravity determinations in a comparatively 
short time with sufficient accuracy to serve the purpose of routine 
inspection work. 

Several different lactometers have been devised in this country 
and Europe. They all depend upon the same principle, namely, 
that bodies floating in a liquid displace a mass of the liquid equal 
to their weight. The only real difl^erence between the varieties of 
lactometers is in the graduations on the lactometer scale. 

Only two kinds af lactometers have come into general use in 
the United States. They are the Quevenne lactometer and the 
N. Y. State Board of Health lactometer (B. of H. lactometer) The 



558 



Analysis of Dairy Products 



Quevenne instrument derives its name from the man who invented 
it. The scale in its stem is graduated from 15 at the top to 40 
at the bottom, each graduation representing a difference of 1.0 on 
the lactometer scale. When the instrument is floated in milk 
of average composition the reading on the scale at the surface of 





riff. 136. 
Quevenne Iiactometer. 



Pig-. 137. 
Baume Hydrometer. 



Tig. 138. 

N. Y. Board of Health or 

Spence Iiactometer. 



the liquid should be about 32. By prefixing "1.0" to the lacto- 
meter reading, the specific gravity is obtained. Thus the specific 
gravity of average milk is 1.032. A vessel that holds exactly 



Lactometers 559 

1000 pounds of water when full Avoiild hold 1032 pounds of milk 
of average composition. It is considered that the Quevenne lacto- 
meter reading of pure milk should not fall below 29.0. 

Lactometers are made to show correct readings at 60^ F. In 
practice, however, it is permissible to make the lactometer reading 
when the temperature is within 10° of 60 either above or below. 
As changes in temperature affect the density of liquids, it is 
then necessary to make a temperature correction. The correction 
on the Quevenne scale is made by adding 0.1 to the lactometer 
reading for each temperature degree above 60° F. and to subtract 
0.1 from the lactometer reading for each degree below 60° F, 
Assuming that the Quevenne lactometer reading of a sample of 
milk was 31 at 67° F., the correction to be added would be 0.7. 
Then 31.0+0.7=31.7. And the specific gravity of the milk would 
be 1.0317. 

Shaw and Eckels^ devised a modification of the Quevenne 
lactometer the graduations of which indicate variations in specific 
gravity as small as 1 in the fourth decimal place. Such an instru- 
ment must have a very slender stem and large body, which makes 
it very fragile, and while it can be used sometimes to advantage 
in the laborator}^, the stronger though less accurate instrument is 
favored for general inspection work. 

The B. of H. lactometer, somtimes known as Spence's lacto- 
meter (from the name of the man who devised it) has a scale 
that is graduated from to 120. There are 60 divisions in the 
scale, each division equaling 2 B. of H. lactometer degrees. When 
the instrument is floated in water the point on the scale is 
located at the surface of the liquid, and when it is floated in 
milk of average composition the reading at the surface of the 
milk is about 110. The instrument shows correct readings in milk 
at 60"^ F., but when the temperature of the milk is within 10 de- 
grees of 60 a correction factor may be used. The correction is made 
by adding 1.0 to the lactometer reading for each 3° F. above 60. 
and subtracting 1.0 for each 3° F. below 60. Thus if a sample 
of milk gave a B. of H. lactometer reading of 112 at 51° F. it 
Avould read 109 at 60° F. 



iV^) 



112— I ^ I =109 



560 



Analysis of Dairy Products 



The relation between the lactometer scales. A reading of 29 
on the Quevenne scale corresponds to a reading of 100 on the B. 
of H. scale. Therefore 1 on the B. .of H. scale equals 0.29 on the 



n\ 



Em 



-.hO: 



-. JE).\A 






il5 



r^ 



-23. 



34.8 



4a 



^~\ 



Lo^ 



I.OZ g 



IDI5 



IP20 



lei^ 



r>k 



^-^ 



.7^ 



1.4, 



-U. 



r23 



.2^ 



3.5 



4.1 



4.3 



v5.6 



-3- 



-4- 



5- 



-6 



N.Y. 

BOARD OF 

HEALTH 

LACTOMETER 



QUEVENNE 
LACTOMLTtR 
5CALL 



SPECIFIC 

GRAVITY 

SCALE 



TWADDELL 
5CALL 



BAUME 
5CALE 



Tig. 139. Relation between B. of H. Iiactonieter, Quevenne Iiactometer 
and Specific Gravity Scales. 



Quevenne scale. (29-^100=0.29.) To convert the B. of H. read- 
ing to the Quevenne reading, multiply the B. of H. reading by 
0.29. Then, by prefixing "1.0" to the product the specific gravity 
is obtained. 



Lactometer Readings 561 

As a result of the extended study of the density of pure milk 
it has been learned that the lactometer readings with rare excep- 
tions fall between 29 and 33.5 for the Quevenne lactometer and 
between 100 and 116 for the B. of H. lactometer. But a correct 
lactometer reading alone is not a guarantee of purity, as removing 
a part of the fat increases the reading and the addition of water 
decreases it. By operating skillfully the lactometer reading may 
be held constant as long as any fat is present. For this reason 
experienced inspectors depend to a considerable extent upon the 
appearance of the milk, especially the richness of the coating and 
the rate of its flow off of the lactometer when the instrument is 
removed from the mass of milk. If the coating appears thin a 
sample may then be taken for chemical analysis. 

The relative effect of fat and solids not fat on the lactometer 
reading". The fat is the lightest solid that milk contains. Any 
increases in its percentage, without an increase in the other 
solids, tends to lower the lactometer reading. It happens that, in 
the elaboration of milk in the udder of the animal, when an in- 
crease in the fat occurs, there is also a sufficient increase in the 
solids not fat to a little more than offset the lowering of the 
density occasioned by the increase in fat. Therefore, it is 
normally found that naturally rich milk gives a higher lactometer 
reading than poor milk. If the percentage of fat rises much 
above 6%, however, the increase in solids not fat is usually not 
enough to counterbalance the fat and the lactometer reading is 
then lowered a little. 

The relative effect of the percentages of fat and solids not 
fat on the density of the milk may be explained by an example. 
Suppose that a sample of milk containing 4 per cent of fat and 
9 per cent of solids not fat gives a Quevenne lactometer reading 
of 33, and that after all of the fat is removed by skimming the 
lactometer reading is 37. The increase in density due to the 
removal of the fat is 4 on the lactometer scale. As there was 
4 per cent of fat in the milk each per cent of fat caused a decrease 
of 1 on the lactometer reading. The whole milk contained 96 
parts of skim-milk (milk serum) and 4 parts of fat, but when the 
fat was removed the remainder was 100 parts skim-milk. As the 
whole milk contained 9 parts of solids not fat the solids not fat in' 
the skim-milk may be calculated by the following proportions : 



562 Analysis of Dairy Products 

96 : 100 : : 9 : X 

X=9.37, or the percentage of solids not fat in the skim-milk. 

If there were no solids not fat in the skim-milk the remainder 
would be water and the lactometer reading would be 0. There- 
fore 37, or the lactometer reading of the skim-milk, divided by 
9.37 gives the effect of 1 per cent of solids not fat in increasing 
the lactometer reading. 

37.00 ^9.37=3.94, or the increased reading due to 1 per cent of 
solids not fat. 

As it was shown above that 1 per "cent of fat decreased the 
lactometer reading 1, it appears that 1 per cent of solids not 
fat has 3.94 times the effect in raising the reading that 1 per 
cent of fat has in lowering it. 

The use of formulas in calculating the composition of milk. 
When the percentage of fat in a sample of milk and the lactometer 
reading are known the approximate composition may be derived 
by the application of a formula. As a result of much study 
different formulas have been developed by Fleischmann, Rich- 
mond, Babcock and others. Babcock's formula is more generally 
used in the United States. 

Babcock's formula: 

(1.) L 

-r +.2F=solids not fat. 
4 ' 

Another formula which gives good results especially with 
naturally rich milk is the following : 

(2.) L+F 

— - — ^solids not fat. 
4 

L=Quevenne lactometer reading at 60^ F. 

F:=Per cent of fat. 

The following example shows the application of forrniila (1). 
A sample of milk contained 3.60 per cent of fat and gave a lacto- 
meter reading of 31.6. What was the percentage (a) of solids 
not fat, (b) of total solids, (c) of water. 
31.6-^4=7.9 
3.6X.2=0.72 
7.9+0.72=8.62, or per cent of solids not fat 



Use; of Lactometers 



563 



8.62+3.60=12.22, or per cent of total solids. 
100.00—12.22=87.78, or per cent of water. 
Another formula- for calculating the solids not fat in milk 
when the N. Y. State Board of Health lactometer is used, is the 
following : 



[{r.O-'] 



+ - =S. N. F. in which 



L=N. Y. Board of Health lactometer reading, 
F=per cent of fat. 

This formula gives fairly good results with milk of average 
composition and with rich milk but the results are liable to be 
a little too high when it is used on milk of low solids content. 

Lactometers used to determine the specific gravity of concen- 
trated milk product. The determination of specific gravity is 
frequently of very great importance in arriving at the approxi- 
mate total solids content of various concentrated milk products. 
The lactometers most commonly used for this purpose are the 
Baume and the Twaddell. In order to permit of closer readings, 
the practice is to make lactometers of various ranges, to suit the 
products upon which they are to be used. In the case of the 
Baume lactometer, the ranges given in Table 95 are those most 
commonly used. 

TABLE 95. 

Range of Baume Lactometers with Products Upon Which They Are to Be 

Used. 



Baume readings 
upon scale 60° F. 
1/10 degree 
divisions. 


Corresponding 

specific gravity 

scale. 


Name of products upon which lactom- 
eters are to be used. 


to 15 


1 to 1.1154 


Evaporated milk, plain condensed 
milk, ice cream mix, condensed but- 
termilk. 


15 to 27 


1.1154 to 1.2288 


Extra heavy plain condensed milk 
and light sweetened condensed 
milk. 


27 to 36 


1.2288 to 1.3302 


Sweetened condensed whole and skim- 
milk. 



564 Analysis of Dairy Products 

The corresponding readings, with converting formulas upon 
true specific gravity, Baume and Twaddell scales are given in 
several tables in appendix, covering a wide range. This affords 
a ready means of converting one scale into another. A compari- 
son of the scale readings of the different instruments used in 
determining the specific gravity of milk and its products is 
shown in Fig. 139. 

CALCULATING THE PERCENTAGE OF ADULTERATION WHEN 
MILK HAS BEEN SKIMMED OR WATERED. 

The forms of milk adulteration that are practiced most fre- 
quently are watering and skimming. They may be very difficult 
to detect where the adulteration is small, and especially difficult 
when there is no means of learning the composition of the 
original pure milk. This must be known where accurate calcu- 
lations are to be made, and it is necessary to also know the per- 
centages of fat and solids not fat in the adulterated sample. The 
latter may be determined by any of the means of analysis at hand. 
In routine work where the aim is to obtain the approximate com- 
position of a large number of samples the solids not fat may be 
determined by means of the formulas given on page 562. 

In the absence of means for determining the composition of the 
original pure milk, it becomes necessary to take as a basis for 
the calculation, the prevailing standard fixed by Legislative or 
Health Board enactments for the location where the adulterated 
milk was exposed for sale. 

Calculating- the percentage of fat removed by skimming". 

Subtract the percentage of fat found in the suspected sample 
from the percentage of fat in the pure milk, or in the absence 
of this information, subtract it from the percentage fixed as a 
standard. Then divide the difference by the percentage of fat 
in the pure milk, or by the standard as the case may be. Multiply 
the quotient by 100 and the product equals the percentage of 
fat that was removed by skimming the pure milk. 

Problem : Suppose that a sample of partially skimmed milk 
contained 2.8 per cent of fat, and that before it was skimmed 
it contained 3.8 per cent of fat. What percentage of the fat was 
removed by skimming? 



Calculating Adultkrations 565 

Solution : 

3.80—2.80=1.00 

1.00-^.038=25.78. per cent of fat removed by skimming. 

Calculating the per cent of water added to milk. This calcu- 
lation should be made on the solids not fat. 

Problem : Suppose that a sample of milk contained 8.8 per 
cent of solids not fat before it was watered, and 7.00 per cent of 
solids not fat after it was watered. What percentage of water 
was added 1 

Solution : 

8.80—7.00=1.80 

1.80-^8.80=.2045 

.2045X100=20.45. or per cent of water added. 

Calculations when the milk is both skimmed and watered. 

The specific gravity of milk is increased by skimming and de- 
creased by watering. Therefore by skimming off some of the fat 
and skillfully adding water the specific gravity or lactometer 
reading may be kept the same after the adulteration that it was 
before. When naturally rich milk is adulterated lightly in this 
way, the adulteration is very difficult to detect unless it is pos- 
sible to learn the composition of the original pure milk. 

Problem : A sample of pure milk contained 4.6 per cent of 
fat and 8.86 per cent of solids not fat. After adulteration by 
skimming and watering the milk contained 3.00 per cent of fat 
and 8.10 per cent of solids not fat. 

What percentage of the fat was removed by skimming and 
what percentage of water was added? 

Solution: (1). Calculate the percentage of water that was 
added as indicated by the relative amounts of solids not fat in 
the two samples : : 

8.86— 8.10=.76 

.76-~8.86=.0857 

.0857X100=8.57, or per cent of water added. 

(2). Calculate the total loss of fat: 

4.6—3.00=1.6 

1.6^4.60=.3478 

.3478X100=34.78, or total per cent of fat lost. 

(3). Calculating the fat removed by skimming: When 
water is added to milk it reduces the percentages of all the 



566 Analysis of Dairy Products 

solids present in the same proportion. Therefore the loss of fat 
by watering must have been 8.57 per cent, or the same per- 
centage as the solids not fat, then : 

34.78 — 8.57=26.21, or percentage of the fat removed by skim- 
ming. This answer is not absolutely correct as the percentage of 
solids not fat in the partly skimmed milk is slightly increased by 
the removal of some of the fat from the pure milk. 

THE DETERMINATION OF VISCOSITY IN LIQUID DAIRY 
PRODUCTS. 

The viscosity of liquid dairy products is most easily and most 
accurately determined by means of the Mojonnier-Doolittle Vis- 
cosimeter, illustrated under Fig. 140. This instrument embodies 
all the principles of the original Doolittle viscosimeter. 

The viscosity readings obtained by this method are relative 
only. Under equal conditions they are strictly comparable. The 
standard viscosimeter is fitted with viscosity balls giving three 
ranges of viscosity as follows : 

(1). Large viscosity ball. Applicable to fresh whole milk or 
skim-milk or other fluids of similar viscosity. 

(2). Medium viscosity ball. Applicable to evaporated milk, 
cream, plain condensed milk, or products of similar viscosity. 

(3). Small viscosity ball. Applicable to sweetened condensed 
milk, superheated milk, or products of heavy viscosity. 

The wires, balls and dials of equal range can all be accurately 
calibrated, and the results obtained within a given range are 
closely comparable. The results are expressed in terms of "de- 
grees of retardation." The dial is graduated in single degree 
divisions up to 360 degrees. 

Temperature exerts a large influence upon viscosity. In 
expressing viscosity the reading should always be reduced to a 
standard temperature. In the case of evaporated milk the cor- 
rections to make for temperature are expressed in Table 141. 
The most satisfactory results are obtained where the viscosity 
determination can be made under standard temperature 
conditions. 



ViSCOSI METER 



567 



DIRECTIONS FOR OPERATING MOJONNIER-DOOLITTLE 
VISCOSIMETER. 

(1). Fasten one end of the wire in the knurled nut upon the 
top of the bent support, and the other end in the dial knob. 
Adjust the vertical position of the dial by raising or lowering 




rig-. 140. Mojonnier-Doolittle Viscosimeter. 



the wire holder until the small lug upon the bottom of the 
dial is in the proper position to engage the trip upon the under 
right hand side of the stand. 



568 Analysis of Dairy Products 

(2). Adjust the horizontal position of the dial until 0^ is 
in a line with the pointer upon the front of the frame when the 
dial is in balance in the air. Center the dial in the open space 
by means of the adjusting screws. 

(3). Place the sample in a cup, or make the test directly 
in the can. Temperature exerts a large influence upon viscosity. 
Viscosity increases as the temperature decreases, or vice versa. 
Therefore, test at constant temperature, or correct for the differ- 
ence in the temperature, using the proper corrections to apply 
upon the product under test. Obviously the correction will vary 
with the product. Properly center the cup or can. 

(4). Lower the ball into to^lt.turnin 

\ ' THIS DIRECTION 

the sample. Turn the dial 
clockwise through one revolu- 
tion, stopping at the 0° in the 
line with the pointer. Hold 
dial in place by means of the 
lug and trip. When ready, 
sharply release the trip. Note 
the degree where the dial stops 
just before it starts upon return ^ "^'^^iki^^ canbeta><ln 

-, „, . .„ „^ WHEN RELLASED, I DiRtCT ftT POINTE.R. MAGNIFYING 

round. This will occur atter dial revolves in I class ovlrpcntlrassurls 

This DIRECTION ACCURACV 

tlu' dial has made one complete, j.^^, 141. Mojonnier-Dooiittie viscosi- 
and part of a second revolution. meter Dial. 

The degree at which the dial stops Avill represent the viscosity of 
tlu' sample, to be expressed as degrees of retardation. 

THE DETERMINATION OF CASEIN IN MILK. 

A. 0. A. C.' Method. "The determination should be made 
wlieii the milk is fresli, or nearly so. When it is not practical to 
make this determination within 24 hours, add 1 part of formalde- 
hyde to 2,500 parts of milk, and keep in a cool place. 
Place about 10 grams of milk in a beaker with about 90 cc. of 
water at 40" to 42° C, and add at once 1.5 cc. of a 10 per cent 
acetic acid solution. Stir with glass rod and let stand from 
three to five minutes longer. Then decant into a filter, wash 
three times with cold water by decantation, pour the wash water 
on the filter each time, then transfer the precipitated casein com- 
pletely to the filter. Wash once or twice on the filter. The 




Casein Tests 



569 



filtrate should be clear or very nearly so. If it is not clear 
when it first runs through, it can generally be made so by two 
or three separate filtrations. after which the washing of the pre- 
cipitate can be completed. Determine the nitrogen in washed 
precipitate and filter paper by the Kjeldahl-Gunning method," 
page 570. 

To calculate the equivalent amount of casein from the nitrogen 
multiply the percentage of nitrogen by 6.38. 

In working with milk which has been kept with preservatives, 
acetic acid should be added in small proportions, a few drops 
at a time, with stirring, and the addition continued until the 
liquid above the precipitate becomes clear, or nearly so. 

The Walker casein test for milk.* In this test, advantage is 
taken of the fact that when formaldehyde is added to proteins 
the neutral character of the protein molecule disappears and the 
acidic properties predominate. In the Walker test, these acidic 
properties are neutralized with standard alkali and the value of 
the alkali in terms of protein is given. ,«a^^ 

Operation. Titrate 9 cc. of the milk in a white cup 
or beaker with tenth-normal sodium hydroxide, 
using 1 cc. of a one per cent phenolphthalein solution 
as an indicator. Stir constantly with a glass rod 
during the titration and titrate to a fairly deep pink 
color. Then add 2. cc. of neutral 40 per cent formalde- 
hyde. Take the reading on the burette containing 
the alkaline solution and again titrate the mixture 
until the same degree of pink color develops. The 
number of cc. of tenth-normal alkaline solution used 
in the second titration multiplied by 1.63 gives the 
percentage of casein in the milk. 

The Hart CEisein test.' Hart makes use of chloro- 
form to dissolve the fat in milk, dilute acetic acid to 
precipitate the casein, a special test tube to measure fo^^Ha'rt^casein 
the volume of casein and a centrifuge to collect it. ^®^*- 

_,, Coui'tesy Louis 

The chloroform-fat solution is throw to the bottom f. Nafts, inc. 
of the test tube in the centrifuge owing to its high specific gravity, 
and the casein collects over the fat solution in a compact layer 




570 Anai^ysis of Dairy Products 

that permits its percentage to be read by means of graduations 
on the side of the tube. 

Operation. Place 2 cc. of chloroform in the casein test tube, 
add 20 cc. of a 0.25 of 1 per cent solution of acetic acid at a 
temperature of 65° to 75° F. (The Acetic acid solution is made 
by diluting 10 cc. of glacial acetic acid with 100 cc. of water, 
then dilute 25 cc. of this solution to 1000 cc. with water). Then 
place 5 cc- of milk at a temperature of 65 to 75° F. into the 
test tube, cover the tube with the thumb, invert and shake the 
tube vigorously for exactly 20 seconds. Within 20 minutes 
centrifuge the tube for 7 minutes at a speed of 2000 revolutions 
per minute. After the tube has been centrifuged, it should stand 
for 10 minutes before reading the percentage of casein. 

DETERMINING THE TOTAL NITROGEN IN MILK. 

A. 0. A. C. Official Method. Place about 5 grams of milk in 
a Kjeldahl digestion flask and proceed without evaporation as 
directed under the Kjeldahl-Gunning metliod for determining 
nitrogen which follows. Multiply the nitrogen by 6.38 to obtain 
the nitrogenous compounds. 

KJELDAHL-GUNNING METHOD FOR DETERMINING NITROGEN. 

Official Method. Place the substance to be analyzed in a 
digestion flask, employing from 0.7 to 3.5 grams, according to 
its proportion of nitrogen. Add 10 grams of powdered potas- 
sium sulphate and from 15 to 25 cc. (ordinarily 20 cc.) of sul- 
phuric acid Sp. Gr. 1.84. Place the flask in a slanting position 
in a holder under a ventilated hood. Heat slowly for 20 or 30 
minutes raising the temperature gradually until foaming ceases 
and the boiling point is reached. Digest for a time after the 
mixture becomes colorless or nearly so, making certain that 
oxidation is complete and all of the nitrogen is in the form of 
ammonia. Let the mixture cool, then dilute with 200 cc. of 
water and add 50 cc. of saturated sodium hydroxide solution 
until strongly alkaline. In order to prevent the loss of am- 
monia, it is a good practice to allow the sodium hydroxide 
solution to run down the side of the flask and under the liquid 
where it is allowed to remain while adding a little zinc dust or 
a few pieces of granulated zinc or pumice stone to prevent 



Casein Tests 



571 



bumping, and a few drops of phenolphthalein indicator. Quickly 
connect the flask to the distilling apparatus, then shake it to 
mix the contents before applying the heat. The indicator will 
show if the solution is alkaline, remembering that in strongly 
alkaline solutions the color of the indicator may disappear. The 
ammonia formed from the nitrogen in the casein is set free 
from the sulphuric acid by the sodium hydroxide and upon 




Figf. 143. KJeldahl Apparatus for Single 
Nitrogren Determination. 

Courtesy Arthiu- H. Thomas Co. 



heating the flask it is driven over with water vapor into the 
condensor where it is condensed to a liquid. Collect the distil- 
late in a flask containing an accurately measured volume (40 to 
50 cc.) of tenth-normal sulphuric acid. The tip of the condenser 
should extend beneath the surface of the tenth-normal solution 
to prevent the escape of ammonia. A few drops of cochineal 
indicator is added to the standard acid solution in the receiving 
flask before beginning the distillation. All of the ammonia 
formed from the nitrogen in the protein will usually be con- 
tained in the first 150 cc. of distillate, the distilling operation 



572 Analysis of Dairy Products 

occupying about one hour. Tlie distillate is then titrated with 
standard alkali. 

The difference between the number of cc. of tenth-normal 
caustic alkali required and the number of cc. of tenth-normal 
acid placed in the flask, equals the number of cc. of tenth-normal 
ammonium hydroxide that would be formed by the ammonia 
distilled over. The weight and percentage of nitrogen may then 
be calculated. Multiply the percentage of nitrogen by 6.38 to 
obtain the nitrogen compounds. 

Problem. Suppose that 50 cc. of tenth-normal acid were 
placed in the flask receiving the distillate from a casein deter- 
mination in Avhich 10 grams of milk were used, and 20 cc. of 
tenth-normal sodium hydroxide were required to neutralize the 
liquid in the flask when the distillation was completed. 

What percentage of casein did the milk contain? 

Solution: 50 — ^20r=30, or cc. of tenth-normal ammonium 
hydroxide formed by the nitrogen in the casein. 

One cc. of tenth-normal ammonium hydroxide contains 0.0014 
gram of nitrogen, 

0.0014X30^=0.042. or gram of nitrogen from the casein, 
0.042X6.38^0.26796, or gram of casein from 10 grams of milk. 
0.26796^-10=0.026796, or gram of casein in 1 gram of milk. 
0.026796X100=2.67963 or the percentage of casein in the milk. 

DETERMINATION OF CASEIN IN MILK CHOCOLATE. 

A. 0. A. C, Tentative Method. It is umiecessary to de-fat the 
chocolate. Weigh 10 grams of the chocolate into a 500 cc. 
Erlenmeyer flask and add 250 cc. of 1 per cent sodium oxalate 
solution. Heat to boiling and boil gently for a few minutes, 
then cool, add 5 grams of magnesium carbonate and filter. 
Determine nitrogen in 50 cc. of this filtrate. Pipette 100 cc. of 
the filtrate into a 200 cc. volumetric flask and dilute almost to 
the mark with water. Then precipitate the casein by the addi- 
tion of 2 cc. of glacial acetic acid or 1 cc. of concentrated sul- 
phuric acid. Make to volume, sliake, filter aiul determine 
nitrogen in 100 cc. of the filtrate. The difi'erence between the 
two nitrogen determinations gives the nitrogen derived from 



Case;in Tests 573 

the casein which, multiplied by 6.38, gives the amount of casein 
present in 2 grams of the sample. 

DETERMINING THE QUALITY OF CASEIN. 

In addition to its use as a food, casein serves for a variety 
of purposes in the industrial arts. The condition and quality 
of the skim-milk and buttermilk from which commercial casein 
is ordinarily made as well as the method of manufacture, usually 
affect to some extent, the composition and physical properties of 
the product found on the market. Where the technical purpose 
for which the casein is to be used is known, the method of its 
manufacture from milk is sometimes stipulated. Yet, it may be 
that casein made by other methods would serve equally well if 
a method for bringing it into solution and workable condition 
were known. 

Butterman" (1920) has shown that the percentage of ash in 
casein varies between 1.28 per cent and 8.6 per cent according 
to the method employed in its manufacture. He also shows that 
when the casein is used in the manufacture of glue the amount 
of water required to give a glue of medium viscosity is a linear 
function of the ash content. Thus the casein made by one 
method, and which contained 1.8 per cent of ash, required 
2.3 parts of water to one part of casein to give a glue of medium 
viscosity, while the casein made by another method, and which 
contained 8.6 per cent of ash required 3.9 parts of water. In 
making the comparisons the amount of water used on a sample 
was varied until the desired viscosity was obtained. 

The operation was carried out as follows : 100 to 200 grams 
of dry powdered casein were weighed and mixed with X parts 
of water. After soaking a few minutes until the casein M'as 
thoroughly wet, a suspension of lime containing one part of 
hydrated lime to 6 parts of water was stirred in. The amount 
of lime used in this suspension was equivalent to 15 per cent of 
the weight of casein used. Finally an amount of sodium silicate 
solution (Sp. Gr. 1.4) equal to 0.7 of the weight of the casein was 
added, and the mixture was then vigorously stirred until all 
particles of casein had dissolved, giving a homogeneous mass. 
Among the characteristics observed in these glues were the 
consistency and glue "life." If the glues exhibited, by simple 
observation, a viscosity intermediate between a thin watery 



574 Analysis of Dairy Products 

mixture and a thick, heav^^ mixture, its consistency was recorded 
as "medium." Similarly a very high viscosity was described as 
"stiff." By the term "life" is meant the period of time between 
the preparation of the glue and the point where it becomes too 
thick to spread properly. 

It is stated that "by making a determination of the ash 
content of a given sample of casein, it is therefore possible to 
tell at once the proper proportion of the ingredients required to 
mix it into a satisfactory glue, regardless of the method by which 
the casein has been prepared. 

Adhesive or strength tests of casein. Dalberg^ (1918) de- 
scribes the following method for determining the adhesive 
strength of casein : Fifty grams of casein ground fine enough 
to pass through a screen with 20 meshes to the inch is weighed 
into a casserole having a known weight, 100 cc. of cold dis- 
tilled water is added, the two mixed well and allowed to stand 
for a short time, when 90 cc. more of distilled water is added 
in which 5 grams of borax have been dissolved. Distilled water 
is then added until the mixture weighs 250 grams, and the cas- 
serole placed in a water bath having a temperature not to exceed 
149° F. (65° C.) and stirred until the casein is dissolved. When 
the casein is completely dissolved more water must be added 
to take the place of that lost by evaporation, so that each 5 
grams of the solution will represent one of casein. Some samples 
of casein may require more than the specified quantity of borax 
or other alkali. No trouble was experienced in dissolving the 
samples reported in the proportion of borax given. 

One hundred grams of china clay or kaolin, previously dried 
at the temperature of boiling water for one hour, is weighed 
into a heavy casserole, and 70 cc. of distilled water added and 
mixed to a smooth paste, care being taken to work up any lumps 
that may settle to the bottom. After weighing the casserole with 
its content of clay paste, 30 grams of the casein solution, repre- 
senting 6 grams of casein, is added to it and thoroughly mixed 
with the paste. A stiff brush is helpful in getting a good mix- 
ture. A thin coating of the mixture is then applied to several 
small sheets of test paper (unsized writing paper serves well), 
by means of a thin brass scraper or camel's hair brush, using care 
to spread uniformly. The casserole is again balanced and 5 



Albumin Determination 575 

additional grams of the casein solution added, the solution well 
mixed and another set of test sheets coated, continuing the 
procedure of adding 5 grams of the casein solution and making 
a set of test sheets until sufficient casein has been added to hold 
the coating mixture properly to the paper. Best results were 
obtained by using the straight edged brass scraper, which re- 
quires that the paper be placed on a perfectly flat surface such 
as a piece of smooth plate glass. When using a brush the coat- 
ing mixture must be placed on very quickly, first lengthwise and 
then crosswise. 

When the sets of test papers having an increase of one gram 
in casein for each succeeding set are perfectly dry, short sticks 
of sealing wax softened by heating at one end are applied Avith 
a fairly firm pressure to various points where the coating is uni- 
form, and allowed to cool. The paper is then held down firmly 
by placing the fingers on each side of the wax and the latter 
pulled away with a steady pull. In case of an insufficient 
quantity of casein the wax M^ill pull only the clay mixture, but 
where sufficient casein has been used it will pull out the paper 
fibers strongly to the edge of the wax, showing that the coating 
material had actually become a part of the paper. Usually a 
transition point is found w^hen the center of the stick of wax 
will pull out the paper fibers partially, while the next set having 
one gram more of casein will pull all the fibers to the extreme 
edge of the wax. A good grade of casein should not require 
more than 8 or 9 grams to hold strongly. 

The strength of casein as shown by this laboratory test bears 
some direct relation to the percentage of casein necessary to use 
in solutions in practical coating work. 

DETERMINING THE ALBUMIN IN MILK. 

Official Method. Exactly neutralize with caustic alkali the 
filtrate from the casein precipitate in the A. 0. A. C. method for 
determining the casein. Add 0.3 cc. of a 10 per cent solution of 
acetic acid and heat the liquid to the temperature of boiling 
water until the albumin "is completely precipitated. Collect the 
precipitate on a filter, wash, and determine the nitrogen therein 
by the Kjeldahl-Gunning method. The nitrogen multiplied by 
6.38 equals the albumin. 



576 Analysis of Dairy Products 

Other nitrogenous compounds. Van Slyke^ gives the fol- 
lowing method for determining the modified proteins, amine 
derivatives and ammonium compounds. Heat the filtrate from 
the albumin precipitate obtained in the above operation to 70° C. 
and add 1 cc. of a 5 per cent sulphuric acid solution, then add 
solid zinc sulphate until the solution is saturated. Hold the 
solution at 70° C. until the precipitate settles, cool, filter, and 
wash the precipitate with a saturated solution of zinc sulphate 
that has been slightly acidified with sulphuric acid. Determine 
the nitrogen in the precipitate by the Kjeldahl-Gunning method. 

To determine the amino-derivatives and ammonium com- 
pounds place 50 c. c. of the milk in a 250 c. c. graduated flask 
and add 1 gram of sodium chloride. Add drop by drop a 12 
per cent solution of tannin until precipitation is complete. Fill 
the flask to the mark with water, shake, and pass through a dry 
filter. Determine the nitrogen in 50 c. c. of the filtrate by the 
Kjeldahl-Gunning method to obtain the amino-derivatives. The 
ammonium compounds are obtained by mixing magnesium oxide 
in slight excess with 100 c. c. of the filtrate, then distilling off 
about 50 c. c. into a measured volume of standard acid. 

ASH DETERMINATION. 

A. 0. A. C. Method. "Weigh about 20 grams of the milk in 
a weighed dish, add 6 c. c. of nitric acid, evaporate to dryness, 
and burn at a low red heat until the ash is free from carbon." 

The burning should be done in a muifle, care being taken to 
avoid heating too rapidly, while burning off the fat and other 
organic matter as flames may carry off some of the mineral 
matter, and too high a temperature later may volatilize some 
of it. 

METHOD FOR DETERMINING LIME IN DAIRY PRODUCTS. 

Description of Method. Two variations of the method are 
possible : 

(1). Measure or preferably weigh the samples into clean 
Babcock test bottles. In all cases except when testing whole 
milk, add to the bottle sufficient distilled water to bring the 
total weight up to 18 grams. Mix samples with the water in the 
bottle very thoroughly. Now add slowly with constant shaking 



Calcium Determination 



57; 



about 15 grams C. P. sulphuric acid; centrifuge for about ten 
minutes. Add sufficient distilled water to float off the fat. Cen- 
trifuge until the last visible traces of fat are gone, adding addi- 
tional water if this might be required. Pour the solution into 
a beaker, and wash out the bottle with three successive small 
portions of distilled water. Add two volumes of 95 per cent 
grain alcohol, and allow to stand over night. Filter, using pref- 
erably, a Gooch crucible with asbestos. Wash the precipitate 
by decantation, using grain alcohol. Dry thoroughly. Ignite at 
a moderate temperature, to a constant weight. If a filter paper 
is used, dry the precipitate in the filter and ignite together. 

(2) Transfer to a beaker the residue remaining in a Mojon- 
nier fat extraction flask at the end of a fat extraction. Neutralize 
the ammonia carefully with C. P. sulphuric acid. Add 10 cc. in 
addition to that required for neutralizing. Add two volumes of 
95 per cent grain alcohol, and allow to stand over night. Pro- 
ceed as under (1), 

Size of Samples Recommended. The size of sample to use 
can be varied with the method employed. Table 96 gives the 
amount recommended under the two methods. Slight variations 
will not affect the accuracy of the results. 

TABLE 96. 
Weight of sample recommended. 



Product. 


Babcock 
method 


Mojonnier 
method 


Whole milk, skim-milk, buttermilk and whey. 


Grams. 
18 


Grams. 
10 


Evaporated milk, plain condensed wliole and 
skim-milk, ice cream mix and cream 


9 


5 


Milk chocolate, cheese, malted milk, whole and 
skim-milk powder and butter 




1 



Experimental evidence upon the accuracy of the method. Ten 

grams of gypsum were heated to a red heat. Weighed samples of 
this were ignited with filter paper, and found upon reweighing 
to have undergone no change in weight. 



578 



Analysis of Dairy Products 



In another experiment a sample of gypsum was treated with 
sulphuric acid diluted 1-5, decanted, filtered, washed, dried in 
electric vacuum oven, and ignited to constant weight. To about 
0.10 gram portions of this ignited product was then added 17 cc. 
of distilled water ; 17 cc. of C. P. sulphuric acid, and after cool- 
ing, 100 cc. of 95 per cent alcohol. After standing over night, 
the precipitate was filtered, dried, ignited and weighed. The 
samples showed no loss in weight. 

Results obtained by the above method. Tlie results obtained 
by means of the above method in the case of different dairy 
products are given in Table 97. 

The method does not apply in the case of sweetened condensed 
milk or other products containing large amounts of sugar, on 
account of the solubility of calcium sulphate in sucrose solu- 
tions. 

TABLE 97. 
Lime Content of Dairy Products As Found by Above Method. 



Test 




Per Cent Caloium Oxide 




Num- 


PRODUCT 






OPERATOR 


ber 




Original 


Duplicate 




1 


Whole milk 


0.122 


0.136 


Author 


2 


Evaporated milk 


0.284 


0.276 


Author 


3 


Evaporated milk 


0.306 


0.302 


Author 


4 


Evaporated milk 


0.344 


0.340 


Author 


.5 


Evaporated milk 


0.364 


0.361 


Author 


G 


Evaporated milk 


0.288 


0.289 


Author 


7 


Evaporated milk 


0.357 


0.354 


Autlior 


8 


Evaporated milk 


0.371 


0.364 


Author 


9 


Whole milk 


0.141 


0.141 


Author 


10 


Powdered skim-milk. . . 


1.410 


1.420 


Autjior 


11 


Buttermilk 


0.159 


0.156 


H. J. Liedel 


12 


Ice cream mix 


0.195 


0.188 


H. J. Liedel 


13 


Cheese 




0.969 


H. J. Liedel 



Conclusions. The method described can be used to determine 
the lime content of all dairy products excepting those containing 
large amounts of sucrose. It is simple and accurate. 



Sugar DivTKrminations 579 

SUGARS. 

The power of reducing sugars to separate oxygen from alka- 
line solutions of certain metallic salts and to precipitate the 
metals as lower oxides is used to advantage in a number of 
methods employed in sugar analysis. Other methods take ad- 
vantage of the power of sugar solutions to rotate a plane of 
polarized light. When the operation is carried out under con- 
ditions that are properly controlled, the angle of rotation pro- 
duced by a sugar solution may be measured and the percentage 
of sugar determined. 

Some of the more practical methods that are of interest in 
the dairy industry for determining sugars are given here. When 
further information on the chemistry of the sugars is desired, a 
more comprehensive work on the subject should be consulted. 

MILK SUGAR DETERMINATIONS. 

A. 0. A. C. Optical Method. Preparation of reagents: (a) 

Dissolve mercury in double its weight of nitric acid, specific 
gravity 1.42, and dilute with an equal volume of Avater. One cc. 
of this reagent is sufficient for the quantity of milk mentioned 
below. Larger quantities may be used without affecting the 
results of polarization. 

(b). Mix 33.2 grams of potassium iodide, 13.5 grams of 
mercuric chloride, 20 cc. of glacial acetic acid and 640 cc. of 
water. 

Determination. The milk should be at a constant temperature 
and its specific gravity determined with a delicate hydrometer 
or lactometer. When greater accuracy is required, pycnometer 
is used. 

The quantities of the milk measured for polarization vary with 
the specific gravity of the milk as well as with the polariscope 
used. The quantity to be measured in an,y case will be found in 
the following table. 

Place the quantity of the milk indicated in the table in a flask 
graduated at 102.4 cc. for a Laurent or 103.6 cc. for a Ventzke 
polariscope (Mohr cc). Add 1 cc. of mercuric nitrate solution 
or 30 cc, of mercuric iodide solution (an excess of these reagents 
does no harm) fill to the mark, agitate, filter through a dry filter, 



5-80 



Analysis of Dairy Products 

TABLE 98. 
Volume of Milk to Be Used 



Specific gravity. 


For polariscopes of 

which the sucrose normal 

weight is 16.19 grams. 


For polariscopes of which 

the sucrose normal 

weight is 36.048 grams. 




c. c. 


c. c. 


1.034 


60.00 


64.40 


1.036 


59.90 


64.30 


1.038 


59.80 


64.15 


1.030 


59.70 


64.00 


1.033 


59.60 


63.90 


1.034 


59.50 


63.80 


1.035 


59.35 


63.70 



and polarize. It is not necessary to heat before polarizing. In 
case a 200 mm. tube is used, divide the polariscope reading by 
3 M^hen the sucrose normal weight of the instrument is 16.19 
grams, or by 2 when the normal weight for the instrument is 
26.048. When a 400 mm, tube is used, these divisors become 6 
and 4 respectively. For the calculation of the above table the 
specific rotary power of lactose is taken as 52.52°, and the cor- 
responding number for sucrose as 66.5°. The lactose normal 
weight to read 100° on the sugar scale for the Laurent instruments 
is 20.496 grams, and for Ventzke instruments, 32.975 grams. In 
case metric flasks are used the weights here mentioned must be 
reduced to 16.160 and 26.000 grams respectively. 

GRAVIMETRIC METHOD A, O. A. C. OFFICIAL, 

Preparation of reagents, (a). Copper sulphate solution. 
Dissolve 34.639 grams of clear crystals of copper sulphate (Cu 
SO4. 5H2O), in water and make up to 500 cc. 

(b). Alkaline tartrate solution. Dissolve 173 grams of pure 
Rochelle salts (sodium potassium tartrate) and 50 grams of pure 
sodium hydroxide in water and dilute to 500 cc. 

(c). Mix equal volumes of solutions (a) and (b) immediately 
before use. (The mixture forms Fehling's solution). 



vSuGAR Determinations 581 

Preparing the milk solution. Dilute 25 ec. of the milk with 
400 cc. of water and add 10 ec. of copper sulphate solution (34.639 
grams of CuSO^. SHoO in water and dilute to 500 cc). Add 
about 7.5 cc. of a solution of potassium hydroxide of such 
strength that one volume of it is just sufficient to completely 
precipitate the copper as hydroxide from one volume of the 
solution of copper sulphate. Instead of a solution of potassium 
hydroxide of this strength 8.8 cc. of a half normal solution of 
sodium hydroxide may be used. After the addition of the alkali 
solution the mixture must still have an acid reaction and contain 
copper in solution. Fill the flask to the 500 cc. mark, mix, and 
filter through a dry filter. 

Place 25 cc. of each reagent (a) and (b) together in a beaker 
and heat to the boiling point. While boiling briskly, add 100 cc. 
of the lactose solution containing not more than 0.300 gram of 
lactose and boil for 6 minutes. Filter immediately through 
asbestos and determine amount of copper reduced. 

The Official Method directs that the amount of copper re- 
duced be determined by one of the following methods : 

(1). Reduction in hydrogen. 

(2). Electrolytic deposition from sulphuric acid solution. 

(3). Electrolytic deposition from sulphuric and nitric acid 
solution. 

(4). Electrolj^tic deposition from nitric acid solution. 

(5). Volumetric permanganate method. 

(6). Direct weighing of cuprous oxide. 

As method (6) is adaptable to the ordinary laboratory it is 
given here : 

Prepare a Gooch crucible with an asbestos felt one fourth of 
an inch thick. Then thoroughly wash the asbestos with water to 
remove small particles, follow successively with 10 cc. of alco- 
hol and 10 cc. of ether, and dry the crucible and contents thirty 
minutes in a water oven at the temperature of boiling water. 
(This drying operation could be shortened by using the Mojon- 
nier Tester solids oven held at 100° C.) 

Collect the precipitate of cuprous oxide on the felt as usual, 
thoroughly wash with hot water, then with 10 cc. of alcohol, and 
finally with 10 cc. of ether. Dry the precipitate 30 minutes in 



582 Analysis of Dairy Products 

TABLE 99. 
Table for the Determination of Lactose (Soxhlet-Wein) 



Milli- 
grams 

of 
Copper 


MilU- 
grams 

of 
Lactose 


Milli- 
grams 

of 
Copper 


Milli- 
grams 

of 
Lactose 


Milli- 
grams 

of 
Copper 


Milli- 
grams 

of 
Lactose 


Milli- 
grams 

of 
Copper 


Milli- 
grams 

of 
Lactose 


Milli- 
grams 

of 
Copper 


Milli- 
grams 

of 
Lactose 


100 
101 
102 
103 
104 


71.6 
72.4 
73.1 
73.8 
74.6 


161 
162 
163 
164 
165 


117.1 
117.9 
118.6 
119,4 
120,2 


222 
223 
224 
225 
226 


163.4 
164,2 
164.9 
165.7 
166.4 


283 

284 
285 
286 

287 


210.7 
211.5 
212.3 
213.1 
213.9 


344 
345 
346 
347 
348 


259.0 
259,8 
260,6 
261.4 
262.3 


105 
106 
107 
108 
109 


75.3 
76.1 
76,8 
77.6 
78.3 


166 
167 
168 
169 
170 


120,9 
121,7 
122.4 
123.2 
123.9 


227 
228 
229 
230 
231 


167.2 
167.9 
168.6 
169.4 
170.1 


288 
289 
290 
291 
292 


214.7 
215.5 
216.3 
217.1 
217.9 


349 
350 
351 
352 
353 


263.1 
263.9 
264.7 
265.5 
266.3 


110 
111 
112 
113 
114 


79.0 
79,8 
80.5 
81.3 
82.0 


171 
172 
173 

174 
175 


124.7 
125.5 
126.2 
127.0 
127.9 


232 
233 
234 
235 
236 


170.9 
171.6 
172.4 
173,1 
173.9 


293 
294 
295 
296 
297 


218.7 
219.5 
220.3 
221.1 
221,9 


354 
355 
356 
357 
358 


267.2 
268 
268.8 
269,6 
270,4 


115 
116 
117 
118 
119 


82.7 
83.5 
84.2 
85,0 
85.7 


176 

177 
178 
179 
180 


128.5 
129.3 
130.1 
130.8 
131.6 


237 
238 
239 
240 
241 


174.6 
175.4 
176.2 
176.9 
177.7 


298 
299 
300 
301 
302 


222,7 
223 , 5 
224,4 
225,2 
225,9 


359 
360 
361 
362 
363 


271,2 
272.1 
272.9 
273.7 
274.5 


120 
121 
122 
123 
124 


86,4 
87.2 
87.9 
88.7 
89.4 


181 
182 
183 
184 
185 


132.4 
133.1 
133,9 
134,7 
135,4 


242 
243 
244 
245 
246 


178.5 
179,3 
180.1 
180.8 
181.6 


303 
304 
305 
306 
307 


226.7 
227,5 
228,3 
229.1 
229.8 


364 
365 
366 
367 
368 


275.3 
276.2 
277,1 
277,9 

278,8 


125 
126 
127 
128 
129 


90.1 
90.9 
91.6 
92.4 
93.1 


186 
187 
188 
189 
190 


136,2 
137,0 
137.7 
138.5 
139.3 


247 
248 
249 
250 
251 


182,4 
183.2 
184.0 
184,8 
185,5 


308 
309 
310 
311 
312 


230.6 
231,4 
232,2 
232.9 
233.7 


369 
370 
371 
372 
373 


279.6 
280.5 
281.4 
282.2 
283.1 


130 
131 
132 
133 
134 


93.8 
94.6 
95.3 
96.1 
96.9 


191 

192 
193 
194 
195 


140.0 
140.8 
141.6 
142.3 
143.1 


252 
253 
254 
255 
256 


186,3 
187.1 
187.9 
188.7 
189.4 


313 
314 
315 
316 
317 


234 . 5 
235.3 
236.1 
236.8 
237.6 


374 
375 
376 
377 
378 


283.9 

284.8 
285.7 
286.5 
287.4 


135 
136 
137 
138 
139 


97.6 
98.3 
99.1 
99.8 
100.5 


196 
197 • 
198 
199 
200 


143.9 
144.6 
145.4 
146.2 
146,9 


257 
258 
259 
260 
261 


190.2 
191.0 
191,8 
192.5 
193.3 


318 
319 
320 
321 
322 


238,4 
239,2 
240.0 
240.7 
241.5 


379 
380 
381 
382 
383 


288.2 
289,1 
289,9 
290,8 
291.7 


140 
141 
142 
143 
144 


101.3 
102.0 
102.8 
103.5 
104.3 


201 
202 
203 
204 
205 


147.7 
148.5 
149.2 
150.0 
150,7 


262 
263 
264 
265 
266 


194.1 
194,9 
195,7 
196,4 
197,2 


323 
324 
325 
326 
327 


242.3 
243,1 
243,9 
244,6 
245.4 


384 
385 
386 
387 

388 


292.5 
293.4 
294.2 
295,1 
296,0 


145 
146 
147 
148 
149 


105.1 
105.8 
106,6 
107,3 
108.1 


206 
207 
208 
209 
210 


151,5 
152.2 
153.0 
153.7 
154.5 


267 
268 
269 
270 
271 


198,0 
198,8 
199,5 
200,3 
201.1 


328 
329 
330 
331 
332 


246,2 
247.0 
247.7 
248.5 
249,2 


389 
390 
391 
392 
393 


296,8 
297,7 
298,5 
299.4 
300,3 


150 
151 
152 
153 
154 


108.8 
109.6 
110.3 
111.1 
111.9 


211 
212 
213 
214 
215 


155.2 
156.0 
156.7 
157.5 
158.2 


272 
273 
274 
275 
276 


201.9 
202,7 
203,5 
204,3 
205.1 


333 
334 
335 
336 
337 


250,0 
250,8 
251.6 
252.5 
253.3 


394 
395 
396 
397 
398 


301 , 1 
302,0 
302.8 
303.7 
304.6 


155 
156 
157 
158 
159 
160 


112.6 
113.4 
114.1 
114.9 
115.6 
116.4 


216 
217 
218 
219 
220 
221 


159.0 
159.7 
160.4 
161.2 
161.9 
162.7 


277 
278 
279 
280 
281 
282 


205.9 
206,7 
207,5 
208,3 
209.1 
209.9 


338 
339 
340 
341 
342 
343 


254 . 1 
254.9 
255.7 
256.5 
257,4 
258,2 


399 
400 


305,4 
306.3 



Sugar Detivrminations ' 583 

a water oven at the temperature of boiling water; cool and 
weigh. The weight of cuprous oxide multiplied by 0.8883 gives 
the weight of metallic copper. Obtain the weight of lactose 
equivalent to the weight of copper found from Table 99. 

DETERMINING THE PERCENTAGE OF LACTOSE AND SUCROSE 
. IN SWEETENED CONDENSED MILK. 

White" has developed a method for determining the percent- 
ages of lactose and sucrose in sweetened condensed milk in which 
the lactose is first determined by the cuprous oxide precipita- 
tion method, then by inverting the sucrose in an aliquot of the 
filtrate and again precipitating the cuprous oxide, the percentage 
of sucrose is obtained. In applying the method certain pre- 
cautions must be observed and corrections made, but the oper- 
ation is not difficult, is fairly rapid, and the results appear to be 
more accurate than those obtained by gravimetric methods here- 
tofore employed. 

Operation. Ten grams of the well mixed sample are weighed 
into a calibrated 250 cc. flask, and approximately 125 cc. of 
water nearly boiling hot added, rinsing down any condensed 
milk attached to the inside of the neck. Shake well for 4 or 
5 minutes, cool to 20" C. and add gradually with shaking, 10 cc. 
of Fehling's copper sulphate solution. Then add 6 cc. of half- 
normal sodium hydroxide solution with shaking. This precipi- 
tates the proteids and fat and leaves a trace of copper sulphate 
in solution. The flask is then filled to the 250 cc. mark with 
water and 1.5 cc. more of water are added to make up for the 
volume of precipitate. Shake until the liquid is homogeneous, 
filter, and discard the first few cc. of the filtrate that pass through. 
The filtrate should have a slight blue color showing that it still 
retains a trace of copper in solution. 

Place 25 cc. each of Fehling's copper sulphate and alkaline 
tartrate solutions in a 400 cc. resistant glass beaker and add 
50 cc. of the filtrate, heat over a flame that will bring the mix- 
ture to boiling in 4 minutes or a few seconds less, then boil for 
2 minutes and filter immediately through asbestos felt in a 
weighed Gooch crucible, using suction to assist in obtaining rapid 
filtration. Rinse the last traces of cuprous oxide onto the filter 



584 Analysis of Dairy Products 

with hot water using a rubber tipped rod to assist and wash the 
precipitate 4 or 5 times with hot water, and once with alcohol. 
Transfer the filtrate to a 250 cc. calibrated flask and set aside for 
use in the sucrose determination. Dry the Gooch crucible and 
contents in an oven at 100° C. for 30 minutes. 

While the cuprous oxide for the lactose determination is 
drying invert the sucrose in the filtrate, and precipitate and filter 
the cuprous oxide from a 50 cc. aliquot of it as follows : Add 
to the filtrate in the 250 cc. flask 9 cc. of 1 to 1 hydrochloric 
acid solution made by dissolving concentrated HCl with an 
equal volume of water. This will bring the mixture to about the 
neutral point. Next add 25 ee. more of the 1 to 1 hydrochloric 
acid to invert the sucrose. Heat rapidly to 70° C. with constant 
stirring to prevent overheating any part of the liquid. Hold the 
liquid at a temperature of 70° C. for 45 minutes, cool somewhat, 
and neutralize with a 50 per cent solution of caustic soda, using 
a few drops of phenolphthalein solution as an indicator. Use care 
in neutralizing not to pass the neutral point ; but if it is passed 
it may be brought back by adding a little of the 1 to 1 hydro- 
chloric acid. Cool to 20° C. and fill the flask to the 250 cc. 
mark. Mix until homogeneous and transfer 50 cc. of it (equal 
to 0.4 gram condensed milk) to a 400 cc. resistant glass beaker 
in which has previously been placed 25 cc. each of the copper 
sulphate and alkaline potassium tartrate solutions. Heat the 
beaker over a flame that will bring the contents to boiling in 4 
minutes or a few seconds less, and boil for two minutes more. 
Filter at once through asbestos felt in a weighed Gooch crucible 
using suction filtration. "Wash the last traces of cuprous oxide 
precipitate from the beaker into the Gooch with hot water using 
a rubber tipped rod to assist, then wash the precipitate 4 or 5 
times with hot water and once with 95 per cent alcohol. Place 
the crucible in a drying oven and dry for 30 minutes at a tem- 
perature of 100° C. 

When the crucible containing the cuprous oxide thrown down 
by the lactose and obtained in the first precipitation has dried 
for 30 minutes, cool it in a desiccator and weigh to determine the 
milligrams of cuprous oxide. The percentage of lactose in the 
sweetened condensed milk may now be calculated as explained ni 
the following problem : 



Sugar Determinations 585 

Suppose that 374.5 milligrams of cuprous oxide are thrown 
down by the lactose. Look in the first column of Munson and 
Walker's table page 587 for the number nearest in size to 374.5. 
It is 370.0. To the right in line with 370.0, in the column marked 
at the head "1 lactose, 4 sucrose" there is found the figure 248.1 
which is the milligrams of lactose equivalent to 370 milligrams of 
cuprous oxide. But there were 374.5 milligrams of cuprous oxide 
and there remains to be found the lactose value of 4.5 milligrams. 
The figure 374.5 falls between the figures 370 and 380 in the first 
column, and the lactose value of 380 as shown in the column under 
the heading "1 lactose, 4 sucrose" is 255.0, Then subtracting 
248.1 from 255.0 gives 6.9, the lactose value of 10 milligrams of 
cuprous oxide, and 6.9 divided by 10 gives 0.69, the lactose value 
of one milligram of cuprous oxide. Then 4.1 multiplied by 0.69 
gives 3.1. Add 3.1 to 248.1 and the sum equals 251.2, the lactose 
value of 374,5 milligrams of cuprous oxide under the conditions 
existing in the determination. 

The percentage of lactose in the sweetened condensed milk 
may then be found by dividing the milligrams of lactose by the 
weight of the condensed milk in the 50 cc. aliquot which was 
used in the determination. As 10 grams of the condensed milk 
was weighed out and made up to 250 cc, 50 cc. represents one 
fifth of 10 grams, or 2 grams (2000 mg.) Then 251.2 divided by 
2000 equals ,1256 and this quotient multiplied by 100 gives 12,56, 
per cent of lactose in the sweetened condensed milk. 

When the cuprous oxide obtained from the inverted sucrose 
determination has dried for 30 minutes, cool in a desiccator and 
weigh to find its weight in milligrams. The percentage of sucrose 
in the condensed milk may then be calculated. To permit ex- 
planation it may be assumed that 378,5 milligrams of cuprous 
oxide were obtained from the aliquot used after inverting the 
cane sugar. But a little lactose remained in the solution after 
the first cuprous oxide precipitation, and a correction must be 
made for it. It amounts to 4.1 milligrams of cuprous oxide as 
found by the average of a large number of determinations. Also 
some sucrose entered into the lactose determination for which a 
correction must be made. The total correction may be calculated 
as follows : The lactose determination in the presence of sucrose 
gave 274.5 milligrams of cuprous oxide which equals 251.2 milli- 



586 Analysis of Dairy Products 

grams of lactose. If the lactose determination were made in the 
absence of sucrose the 251.2 milligrams of lactose would have 
thrown down only 366.4 milligrams of cuprous oxide. (This may 
be seen by finding the cuprous oxide equivalent in the first 
column of Munson and Walker's table, for 251.2 milligrams of 
lactose in the column under the heading "lactose"). The differ- 
ence between 374.5 and 366.4 is 8.1, or the number of milligrams 
of cuprous oxide thrown down in the lactose determination due 
to the inversion of some sucrose during the operation. Since only 
a one-fifth aliquot was used later in making the sucrose determi- 
nation the correction to be added is one-fifth of 8.1 milligrams 
or 1.6 milligrams. This positive correction of 1.6 milligrams 
combined with the negative correction of 4.1 milligrams equals 
2.5 milligrams to be subtracted from the 378.5 milligrams, which 
leaves 376 milligrams of cuprous oxide that may finally be credit- 
ed to the inverted sucrose. 

Next find in Munson and Walker's sugar table, first column, 
the figures nearest in size to 376. They are 380 and 370. The 
invert sugar value for 370 milligrams of cuprous oxide as given in 
the invert sugar column of the table is 177.7 milligrams and the 
invert sugar value for 380 milligrams of cuprous oxide is 183.0 
Therefore a difference of 10 milligrams of cuprous oxide is here 
equal in invert sugar to the difference between 183.0 and 177.7, 
or 5.3 milligrams. Then one milligram of cuprous oxide equals 
5.3 divided by 10, or 0.53 milligram of invert sugar. Accepting 
177.7 milligrams as the invert sugar value of 370 milligrams of 
cuprous oxide there remains to be found the dift'erence between 
370 and 376, or 6 milligrams of cuprous oxide. Since one milli- 
gram of the oxide as shown above equals 0.53 gram of invert 
sugar, 6 milligrams equals 6 times 0.53, or 3.18 milligrams. Then 
177.7 plus 3.18 equals 180.88, milligrams of invert sugar in the 
aliquot used in making the sucrose determination. Since the 
weight of invert sugar is 5 per cent greater than the weight of 
sucrose before inversion, it is necessary to multiply the 180.88 by 
100 minus 5, or 95 per cent to obtain the milligrams of sucrose in 
the aliquot used in the determination. Thus 180.88 times 95 
per cent gives 171.83, milligrams of sucrose. The aliquot used in 
making the lactose determination equaled 2.0 grams of condensed 
milk and the aliquot used for the sucrose determination was 



Sur.AR Determinations 



587 



TABLE 100. 

IHUinson and Walker's Table for Calculating Dextrose, Invert Sugar, Invert 

Alone, Invert Sugar in the Presence of Sucrose (0.4 Gram and 2 Grams 

Total Sugar), Lactose, Lactose and Sucrose (2 Mixtuies) and 

Maltose (Crystalized). 

Expressed in Milligrams. 











Invert Sugar 


Lactose 


Lactose and 


Mal- 








Dex- 




and Sucrose 




Sucrose 


tose 


Cuprous 


Cuprous 


Copper 


trose 


Invert 














Oxid 














Oxid 


(Cu) 


(d-glu- 


Sugar 


0.4 gm. 


2 gms. 


C,2H22 


1 Lac- 


1 Lac- 


C12H22 


(CU2O) 


(CujO) 




cose) 




Total 


Total 


On+ 


tose, 4 


tose, 12 


O11+ 












Sugar 


Sugar 


H2O 


Sucrose 


Sucrose 


H2O 




10 


8,9 


4.0 


4.5 


1.6 




6.3 


6.1 




6.2 


10 


20 


17.8 


8.3 


8.9 


6.1 




12.5 


12.1 




14.6 


20 


30 


26.6 


12.6 


13.4 


10.7 


4.3 


18.8 


18.2 




22.9 


30 


40 


35.5 


16.9 


17.8 


15.2 


8.8 


25.5 


24.7 




31.3 


40 


50 


44.4 


21.3 


22.3 


19.7 


13.4 


32.3 


31.3 




39.6 


50 


60 


.53.3 


25.6 


26.8 


24.3 


18.0 


39.2 


37.9 




48.0 


60 


70 


62.2 


30.0 


31.3 


28.9 


22.6 


46.0 


44.6 


41.9 


56.3 


70 


80 


71.1 


34.4 


35.9 


33.5 


27.3 


.52.9 


51.3 


47.8 


64.6 


80 


90 


79.9 


38.9 


40.4 


38.2 


31.9 


59.7 


57.9 


53.7 


73.0 


90 


100 


88.8 


43.3 


45.0 


42.8 


36.6 


66.6 


64.6 


59.6 


81.3 


100 


110 


97.9 


47.8 


49.6 


47.5 


41.3 


73.5 


71.3 


65.6 


89.7 


110 


120 


106.6 


52.3 


.54.3 


52.3 


46.0 


80.3 


78.0 


71.5 


98.0 


120 


130 


115.5 


56.8 


58.9 


56.9 


50.7 


87.3 


84.7 


77.5 


106.4 


130 


140 


124.4 


61.3 


63.6 


61.6 


55.5 


94.1 


91.4 


83.5 


114.7 


140 


150 


133.2 


65.9 


68.3 


66.4 


60.2 


101.0 


98.1 


89.5 


123.0 


150 


160 


142.1 


70.4 


73.0 


71.2 


65.5 


107.9 


104.8 


95.6 


131.4 


160 


170 


151.0 


75.1 


77.7 


76.0 


69.8 


114.8 


111.6 


101.6 


139.7 


170 


180 


159.9 


79.7 


82.5 


80.8 


74.6 


121.6 


118.3 


107.7 


148.0 


180 


190 


169.8 


84.3 


87.2 


85.6 


79.5 


128.5 


125.1 


113.8 


156.4 


190 


200 


177.7 


89.0 


92.0 


90.5 


84.4 


135.4 


131.9 


119.8 


104.7 


200 


210 


186.5 


93.7 


96.9 


95.4 


89.2 


142.3 


138.6 


126.0 


173.0 


210 


220 


195.4 


98.4 


101.7 


100.3 


94.2 


149.3 


145.4 


132.1 


181.4 


220 


230 


204.3 


103.2 


106.6 


105.2 


99.1 


156.2 


152.2 


138.2 


189.7 


230 


240 


213.2 


108.0 


111.5 


110.1 


104.0 


163.1 


159.0 


144.4 


198.0 


240 


250 


222.1 


112.8 


116.4 


115.1 


109.0 


170.1 


165.8 


150.6 


206.3 


250 


260 


231.1 


117.6 


121.4 


120.1 


114.0 


177.0 


172.6 


156.8 


214.7 


260 


270 


239.8 


122.5 


126.4 


125.1 


119.0 


184.0 


179.4 


163.0 


223.0 


270 


280 


248.7 


127.3 


131.4 


130.2 


124.1 


190.9 


186.3 


169.3 


231.3 


280 


290 


257.6 


132.3 


136.4 


135.3 


129.2 


197.8 


193.1 


175.5 


239.6 


290 


300 


266.5 


137.2 


141.5 


140.4 


134.2 


204.8 


199.9 


181.8 


247.9 


300 


310 


275.4 


142.2 


146.6 


145.5 


139.4 


211.8 


206.8 


188.1 


256.3 


310 


320 


284.2 


147.2 


151.7 


150.7 


144.5 


218.7 


213.6 


194.4 


264.6 


320 


330 


293.1 


152.2 


156.8 


155.8 


149.7 


225.7 


220.5 


200.8 


272.9 


330 


340 


302.0 


157.3 


162.0 


161.0 


154.8 


232.7 


227.4 


207.1 


281.2 


340 


350 


310.9 


162.4 


167.2 


166.3 


160.1 


239.7 


234.3 


213.5 


289.5 


350 


360 


319.8 


167.5 


172.5 


171.5 


165.3 


246.7 


241.2 


219.2 


297.8 


360 


370 


328.7 


172.7 


177.7 


176.8 


170.6 


253.7 


248.1 


226.3 


306.1 


370 


380 


337.5 


177.9 


183.0 


182.1 


175.9 


260.7 


255.0 


232.8 


314.5 


380 


390 


346.4 


183.1 


188.4 


187.5 


181.2 


267.7 


261.9 


239.2 


322.8 


390 


400 


355.3 


188.4 


193.7 


192.9 


186.0 


274.0 


268.2 


245.1 


330.2 


400 


410 


364.2 


193.7 


199.1 


198.3 


191.9 


281.7 


275.8 


252.3 


339.4 


410 


420 


373.1 


199.0 


204.6 


203.7 


197.3 


288.8 


282.8 


258.8 


347.7 


420 


430 


382.0 


204.4 


210.0 


209.2 


202.7 


295.8 


289.8 


265.4 


356.0 


4.30 


440 


390.8 


209.8 


215.5 


214.7 


208.8 


302.8 


296.8 


272.0 


364.3 


440 


450 


399.7 


215.2 


221.1 


220.2 


213.7 


309.9 


.303.8 


278.6 


372.6 


450 


460 


408.6 


220.7 


226.7 


225.8 


219.2 


316.9 


310.8 


285.2 


380.9 


460 


470 


417.5 


226.2 


232.3 


231.4 


224.8 


323.9 


317.7 


291.8 


389.2 


470 


480 


426.4 


231.8 


237.9 


237.1 


230.3 


331.0 


324.7 


298.5 


397.2 


480 


490 


435.3 


237.4 


243.6 


242.7 


236.0 


338.0 


331.7 


305.1 


405.8 


490 



588 Analysis of Dairy Products 

one-fifth of that amount, which is 0.4 gram, or 400 milligrams. 
Then 171.83 divided by 400 milligrams gives 0.4297, which, multi- 
plied by 100, gives 42.97, per cent of sucrose in the sweetened 
condensed milk. 

TABLE 101. 
A Comparison of Results by White's Method. 



Batch 


Sample 


Per Cent Calcu- 
lated from Lbs. of 
Sugar and Lbs. of 
Condensed Milk 


Per Cent 
of Sucrose 
by White's 

Method 


Percentages Obtained 

in 3 Separate Aliquots 

of the Filtrate from 

Sample No. 3 of 

Each Batch 


1 


1 


43.75 


43.85 






2 


1 


45.40 


45.25 






2 


2 


45.40 


45.04 






2 


3 


45.40 


45.16 


45.03 


45.02 


3 


1 


42.81 


42.98 






3 


2 


42.81 


42.99 






3 

4 
Condensed skim-milk 


3 


42.81 


42.96 


42.94 


42.85 


1 


47.56 


47.44 








2 


47.56 


47.20 








3 


47.56 


47.43 


47.41 


47.23 



THE POLARIMETRIC METHOD FOR DETERMINING LACTOSE AND 
SUCROSE IN SWEETENED CONDENSED MILK. 

The polarimetric method for determining sugars in sweetened 
condensed milk, originally developed by Harrison^", is most 
accurate and reliable. It also requires less of the operator's time 
than the gravimetric methods, but there is danger of error occur- 
ing in the results unless the analyst understands his work and 
follows directions closely. For determining the percentage of 
lactose in milk products that have been highly heated, as in 
sterilized evaporated milk, it is safer to use the gravimetric 
method, as the high temperature to which the milk sugar has been 
subject is believed to cause a slight change of the specific rota- 
tion. 

The polarimetric method is carried out as follows : For in- 
struments reading in the Ventzke scale weigh into a 100 cc. flask 



Sugar Determinations 589 

26.048 grams of the homogeneous sample, add boiling hot water 
and shake thoroughly until the substance is fluid and all sugar 
crystals are dissolved, allow to stand over night preferably at a 
temperature of 30° to 35° C. to destroy mutarotation. The addi- 
tion of a little ammonia at this point does not seem to destroy 
all mutarotation. It is frequently advised to boil the solution 
before allowing it to stand over night. In such case the flask 
should be heated in a boiling water bath, as there is danger of 
superheating parts of the substance when using a flame or hot 




Pig-. 144. Polariscope and Tube for Sugrar Solution. 

Courtesy E. H. Sargent & Co. 



plate. After the solution has stood the proper length of time, 
cool to 15° C, add 3 cc. of acid mercuric nitrate, make up the 
volume to 100 cc. and add 4 cc. of water in excess for condensed 
whole milk, and 2.5 cc. in excess for condensed skim-milk. Shake 
thoroughly, filter, fill the polariscope tube with some of the 
filtrate and take the polariscope reading at about 20° C. within 
five minutes after adding the mercuric nitrate. 

Place another portion of the filtrate in a flask, weigh and 
place the flask in boiling water for 7 minutes, cool rapidly, re- 
weigh and make up any loss in weight due to evaporation. Filter, 
fill the polariscope tube with some of the filtrate and polarize to 



590 Analysis of Dairy Products 

obtain the invert reading, noting- the temperature. The direct 
and invert reading should be made at the same temperature. If 
not exactly at the same temperature use the invert reading tem- 
perature in the formula. 

The per cent of cane sugar is then obtained by the use of 
Clerget's formula: 

100 (D — I) 



142.68 



S = Per cent of cane sugar 

D = Direct reading 

I = Invert reading 

T = Temperature of invert reading- 
Lactose (Ci. H,, Oy, f H, 0) '/, = (D— S) X 1.266. 

Bigelow and McElroy's Modification of the Polariscope Meth- 
od. "Thoroughly mix the condensed milk and weigh 26.048 
grams into a 100 cc. sugar flask, add water and boil. Add 30 
cc. of mercuric iodide solution (58 grams of potassium iodide, 22 
grams of mercuric chloride, and 32 cc. of glacial acetic acid 
dissolved in water and made up to a liter). Make up to the 100 
cc. mark with water, mix thoroughly by shaking and filter 
through a dry filter. Polarize a portion of the filtrate after re- 
jecting the finst part that passes through. 

"Weigh out another 26.048 gram quantity of the condensed 
milk, add water to dissolve and heat to 55° C. Add half a cake 
of compressed yeast to invert the sucrose and hold the mixture at 
55° C. for five hours to complete the inversion. Add the clarify- 
ing solution, cool, make up to 100 cc. with water and filter. Obtain 
the invert reading of a portion of the filtrate. Calculate the 
percentage of cane sugar by the Clerget formula as follows : 



A — b 

S = 



t 
142.66 — 2 



Milk Powder Tests 591 

S — the per cent of cane sugar I 

A = the direct reading 

b = the invert reading 

t^rtemperature of the solution when the reading is taken. 

In applying the method several determinations should be made 
and the average of these taken. Unless the condensed milk is 
mouldy or decomposed invert sugar should be absent from the 
sample." 

QUALITATIVE TEST FOR SUCROSE IN MILK POWDER.'^ 

Preparation of Di-phenylamine. Dissolve 1 gram of di- 
phenylamine in 20 cc. of 95% alcohol and mix it with 60 cc. of 
glacial acetic acid and 120 cc. of dilute hydrochloric (equal parts 
of concentrated hydrochloric acid and water). The reagent 
should be prepared from its alcoholic solution within a few 
hours of being used. 

Preparation of ammoniacal lead acetate. Add 560 cc. of water 
to 430 grams of neutral lead acetate and 130 grams of litharge, 
and boil for half an hour, cool, decant the clear solution, and re- 
duce its specific gravity to 1.15 with cold, recently boiled, distilled 
water. Immediately before use mix 2 volumes of the lead acetate 
solution with 1 volume of ammonia (10 grams NH.. in 100 cc). 

Operation. Warm one gram of the milk powder Avith 10 cc. 
of water in a test tube and add 10 cc. of freshh' made ammoniacal 
lead acetate solution. Shake thoroughly and filter at once. To 
about 4 cc. of the filtrate, add about 8 cc. of the di-phenylamine 
reagent and place the tube in a boiling water bath for 10 minutes. 
The presence of sucrose is indicated by the formation of a blue 
color. 

Milk containing 0.05 per cent of sucrose gives a faint tint of 
blue and 0.1 per cent gives a strong reaction. 

TEST FOR RELATIVE SOLUBILITY OF MILK POWDER. 

Reconstitute the milk powder in the following proportion : 
9 parts of milk powder to 91 parts of water when testing 

skim-milk poAvder. 

12 parts of milk pawder to 88 parts of water when testing 

whole milk powder. 



592 Analysis of Dairy Products 

Using the "Wizard" or "Lorenz" Sediment Tester proceed 
as follows : 

Dry and weigh all disks carefully. 

Use about 200 cc. of the reconstituted milk and make sediment 
test in the regular way, passing the milk through the filter twice. 

Rinse tester thoroughly with distilled water before removing 
disk. 

Dry disk thoroughly and weigh. 

The increase in weight of the disk divided by the weight of 
milk powder contained in the 200 cc. solution multiplied by 100 
equals the per cent of insoluble substance in the milk powder. 

LECITHIN DETERMINATION. 

The lecithin in milk may be determined by the method of 
Bordas and Rackowski.^'^ 

Procedure. To a mixture consisting of 100 cc. of 95 per cent 
alcohol, 100 cc. of water and 10 drops of acetic acid add very 
slowly with constant stirring 100 cc. of the milk. Separate the 
coagulum by filtration, close the lower end of the funnel tube 
and add 50 cc. of warm absolute alcohol. By means of a platimum 
spatula stir the coagulum in the alcohol and after a few minutes 
open the funnel tube and allow the alcohol to run into the filtrate. 
Wash the coagulum three times in this manner. Remove the 
alcohol from the filtrate by distillation and dry to drive off the 
last traces. Extract the residue with a mixture of equal parts 
of ether and alcohol, filter, and heat on a water bath until all ether 
is evaporated. Saponify the remaining alcoholic solution with 
caustic potash and add dilute nitric acid to decompose the soap 
formed. Heat the mixture to boiling and evaporate on the water 
bath to dryness, add 10 cc. of concentrated nitric acid, then add 
powdered potassium permanganate until the color remains for a 
short time. Add a few drops of a dilute solution of sodium nitrite 
to dissolve any manganese oxide that forms and boil. Precipitate 
the phosphoric acid by adding ammonium molybdate solution 
and after it has stood for at least 12 hours filter, and dissolve 
the precipitate with ammonium hydroxide. Wash the filter with 
hot water, cool, and add hydrochloric acid until nearly neutral. 
Add a small excess of magnesia mixture, drop by drop, with con- 
stant stirring. Let stand for 15 minutes, then add about 10 cc. of 



Cn Ric Acid TiisTS 593 

concentrated ammonia, and after standing at least four hours 
filter. Wash the precipitate with 3 to 5 per cent ammonia solution 
to remove chlorides, ignite, cool in a desiccator and weigh as mag- 
nesium pyrophosphate MggPoO^. Multiply the weight by 
0.36036 to obtain the magnesia (MgO), and the phosphoric acid 
multiplied by 7.27 gives the quantity of lecithin. 

THE CITRIC ACID CONTENT OF MILK AND METHODS FOR 
DETERMINING IT. 

Fresh milk contains between 0.1 and 0.2 per cent of citric 
acid, the content varying primarily according to the individuality 
of the cow from which the milk is obtained. It is probable that 
the citric acid content may also be affected slightly by the feed of 
the cow. The acid is present in milk in the form of salts of the 
alkaline elements, but investigators are not in definite agreement 
as to which of these elements are united with it. During the 
aging of milk and the development of lactic acid by the action 
of bacteria, the citric acid content gradually decreases. Other 
factors may also influence the rate at which it disappears. 

Supplee and Bellis^* after making a study of the citric acid 
content of fresh milk and concentrated milk products make the 
following statement : — 

"There is apparently no effect upon the citric acid content of 
milk caused by heating during the manufacture of evaporated, 
condensed, and dried milks. The results indicate that the amounts 
found in these products, if subject to variation, must be attributed 
to causes other than heat." 

The methods used by Supplee and Bellis for determining the 
citric acid content and a table showing the relative accuracy of 
the methods follow. 

Determination of Citric Acid in Milk. — 50 c.c. of milk are 
treated with 10 cc. of dilute sulfuric acid (1:1) and thoroughly 
agitated. 2 cc. of 40 per cent potassium bromide solution and 20 
ce. of a solution of phosphotungstic acid are then added. After a 
thorough mixing, the precipitate is separated by filtration. To the 
perfectly clear filtrate in an Erlenmeyer flask is added an excess 
of freshly prepared saturated bromine water (usually between 
5 and 10 cc). The mixture is then placed on the water bath at 
a temperature of from 48-50° C. for about 5 minutes. After re- 



594 Anai^ysis of Dairy Products 

moving from the bath, add rapidly from a burette 25 cc. of potas- 
sium permanganate solution (5 per cent) drop by drop with 
frequent interruptions, and with constant and vigorous shaking, 
avoiding a temperature during the oxidation exceeding 55° C. 
Set the flask aside until the hydrated peroxide of manganese 
begins to settle. The supernatant liquid should be dark brown 
showing an excess of permanganate. Add more permanganate if 
an excess is not indicated. When the precipitation assumes a 
yellow color and most of it is dissolved, add drop by drop a clear 
solution of ferrous sulfate until the hydrated peroxide of 
manganese and excess of bromine are removed. Allow the solu- 
tion to cool, shaking occasionally. Allow the mixture to stand 
over night. Collect by means of gentle suction on a tared Gooch 
crucible provided with a thin pad of asbestos previously dried 
over sulfuric in a vacuum desiccator ; wash with water slightly 
acidified with sulfuric acid and finally wash twice with water. 
Dry the precipitate to constant weight over sulfuric acid in a 
vacuum desiccator protecting the precipitate from strong light. 
The weight of the precipitate multiplied by the factor 0.424 give 
the equivalent weight of anhydrous citric acid in the sample. 

Determination of Citric Acid in Milk Powder.— Weigh 5 gm. 

of powder into a beaker and reconstitute with 45 cc. of warm 
Avater. Mix thoroughly and proceed as with liquid milk. 

Determination of Citric Acid in Sweetened Condensed Milk. — 

Weigh out 25 gm. of the sample and add 200 cc. of 95 per cent 
alcohol. Mix thoroughly and filter. To the filtrate add enough 
0,25 N barium hydroxide to almost neutralize the solution and 
then 5 cc. of 50 per cent barium acetate in order to insure an 
excess of barium. Add about 150 cc. of 95 per cent alcohol and re- 
flux until the precipitate settles readily after being shaken. Filter 
and thoroughly wash the precipitate in the flask and on the paper 
with 95 per cent alcohol. Transfer the precipitate from the filter 
to the flask with a jet of hot water. Boil until alcohol can no 
longer be detected by odor and add enough sulfuric acid (1 :5) 
to precipitate all of the barium originally present and to allow 
2 cc. in excess. Evaporate to a volume of 60 to 70 cc. ; cool and 
add an excess of bromine water. Filter and add 10 cc. of potas- 
sium bromide, then place on the water bath at a temperature of 
48-50'^ C. and proceed as with liquid milk. 



Citric Acid Tests 



595 



TABLE 102. 
Percentage of Citric Acid Recovered from Milk Products. 



Original 

After adding 0.02 per cent 
After adding 0.05 per cent 
After adding 0. 10 per cent , 
After adding 0.15 per cent 



Liquid Milk 



No. 1 No. 2 



0.132 
0.179 
0.279 



0.129 
0.180 
0.279 



Liquid Milk 
and Sugar 



No. 1 No. 2 



0.131 
0.182 
0.279 



0.130 
0.179 
0.275 



Evaporated 
Milk 



No. 1 No. 2 



0.202 
0.252 



0.204 
0.253 



Conden.sed 
Milk 



No. 1 No. 2 



0.096 
0.110 
0.143 
0.190 



0.090 
0.104 
0.148 
0.197 



"The relative accuracy of these methods is shown in Table 102 
in Avhich is given the results of duplicate determinations on liquid 
milk with and without sugar, on evaporated milk, and on sweet- 
ened condensed milk ; also duplicate results from each of these 
products after known amounts of citric acid in the form of sodium 
citrate had been added. It will be noted that the maximum vari- 
ation in duplicate results does not exceed 0.006 per cent ; it is 
believed, therefore, that any significant variations occurring in the 
products examined were easily detected by the methods used. 

Second Method for Determining Citric Acid in Milk Powder. 
This method^'' depends upon the oxidation of citric acid to ace- 
tone di-carboxylic acid, and the precipitation of a double salt of 
mercury acetone di-carboxylate and basic mercury sulphate. 



CH2.C00 

2 CO, Mi 

CHxCOO^ 



SO* 



H»0, 



^^ 



HgO 



/ 



H 



g 



Five grams of milk powder are made into a paste with warm 
water and washed into a 200 cc. calibrated flask, with about 120 
cc. of water. Cool to room temperature and add 50 cc. of the mer- 
cury reagent* and 2 cc. of Kahlbaum's phospho-tungstic acid 



•Preparation of the Mercury Sulphate Reagent: Boil G8.5 grams of 
mercuric sulphate in a liter of water and add a mixture of equal parts of 
concentrated sulphuric acid and water until the basic salt at first precipi- 
tated is completely dissolved. Boil to less than a liter, filter, cool, and make 
up to a liter. Five c. c. of the reagent should require 7 to 8 c. c. of normal 
sodium hydroxide to give a permanent turbidity. 



596 Analysis of Dairy Products 

solution. Make the volume up to 200 cc. with water. Thoroughly 
mix and filter through dry paper, refiltering the first portions of 
tlie filtrate. Transfer 100 cc. of the clear filtrate to a beaker and 
raise to the boiling point over a flame. Remove the flame and 
add 1% potassium permanganate solution drop by drop with con- 
stant stirring until the precipitate assumes a brown color owing 
to precipitated manganese hydroxide. Place the flame under the 
beaker and add hydrogen peroxide solution (10 to 20 volumes) 
to the boiling solution, drop by drop, to remove the precipitated 
manganese. Five to 10 drops should usually be sufficient. Collect 
the precipitate on a Gooch crucible, wash with water, dry at 
100° C. and weigh. Multiply the weight obtained by 0.271 to 
obtain the weight of citric acid (CeHgO^). 

STANDARD SOLUTIONS. 

In volumetric methods of chemical analysis solutions of known 
chemical strength are employed. They are called "standard" 
solutions. When a standard solution contains in 1000 cc. a quan- 
tity of the active reagent chemically equal to one gram of 
hydrogen it is defined as a "normal" solution. As 1000 cc. of a 
normal solution of any reagent is chemically equal to one gram 
of hydrogen it follows that equal volumes of normal solutions of 
different reagents are chemically equal to each other. The term 
"normal" as applied to solutions of chemical reagents is some- 
times expressed by the symbol "N/1." As normal solutions are 
rather concentrated for use in making accurate analyses, solu- 
tions of one-tenth the normal strength are usually employed. 
Solutions of one-tenth normal strength may be expressed by the 
symbol "N/10." 

A standard acid solution and a standard alkaline solution are 
a necessity in every chemical laboratory. Since any error in 
their accuracy will cause a corresponding error in results obtained 
by their use great care should be taken to determine their exact 
strength. Any soluble acid or base may be used in making a 
standard acid solution or alkali solution respectively. But hydro- 
chloric acid or sulphuric acid are usually preferred for making 
the stock standard acid solution and sodium or potassium hydrate 
are preferred for making the standard alkali solution. 



Standard vSolutions 597 

First Method, When it is desired to make up a hydrochloric 
acid solution of tenth-normal strength, first make up a solution 
of approximate strength, making certain that it is somewhat 
stronger than is finally desired. Then, after determining its 
exact strength by the method given below, calculate and add the 
volume of water necessary to bring the solution to tenth-normal 
strength. 

Operation: When the specific gravity of the concentrated 
hydrochloric acid, from which the standard solution is to be 
made, is 1.170 or more place about 9.5 cc. of it in a liter flask 
graduated at the 1000 cc. mark. Fill the flask to the mark with 
distilled water and mix the solution thoroughly. Place 25 cc. 
of the solution in a glass stoppered, 150 cc. Erlenmeyer flask and 
add 75 cc. of distilled water. Add slowly and with constant 
agitation a 5 per cent solution of silver nitrate until precipitation 
is complete and a slight excess of silver nitrate is present. About 
15 cc. of the silver nitrate solution will usually be sufficient. The 
precipitate should be protected from the light as much as possible 
by wrapping the flask in a piece of black cloth during the whole 
operation. While it is very important to have a slight excess of 
silver nitrate present in order to obtain proper flocculation of the 
precipitate, any large excess should be avoided as the precipitate 
is slightly soluble in a silver nitrate solution. Immediately after 
adding the silver nitrate, stopper the flask, cover it completely 
with the black cloth and shake it vigorously for five minutes. 
The precipitate should then settle quickly and leave a clear 
supernatant liquid that is entirely free from cloudiness. Filter 
with the aid of suction through a previously prepared, dried and 
weighed Gooch filter. Carefully break up the compact mass of 
silver chloride on the filter with a small glass rod and rinse the 
last traces of precipitate from the flask and onto the filter using 
distilled water containing one cc. of concentrated nitric acid 
per 100 cc. of M^ater. Continue to wash the precipitate with the 
acidified water, to remove the last traces of silver nitrate, until 
a few cc. of the water passing through shows no turbidity upon 
the addition of a few drops of hydrochloric acid. When fissures 
appear in the precipitate during the washing process close them 
by means of a glass rod. After washing is completed place the 
crucible in an oven at a temperature of about 140° C. for 2 or 3 



598 Analysis of Dairy Products 

flours, cool in a desiccator and weigh. Heat again for one hour, 
weigh, and repeat until constant weight is obtained. 

Having obtained the exact weight of the silver chloride pre- 
cipitate the weight of hydrochloric acid in one cc. of the solution 
may then be obtained by applying the following rule : 

The molecular weight of one substance is to the molecular 
weight of a second substance, as the actual weight in grams of the 
first is to the actvial weight in grams of the second, when the 
molecules are chemically equal. 

The reaction between the hydrochloric acid and the silver 
nitrate is shown in the equation: 

HCl+AgNO.^AgCl+HNOo 

The molecular weight of AgCl is 143.33 and the same for 
HCl is 36.45. Assuming that the silver chloride precipitate ob- 
tained above weighed 0.3828 gram the following proportion may 
be formed : 

143.33 : 36.45 :: 0.3828 : X 

(36.45X0.3828) 

X— — -— -=0.09734, or gram of HCl in 25 cc. of 

143. GO 

the acid solution, 

0.09734-^-25=0.003893, or gram of HCl in one cc. 
The weight of hydrochloric acid in one cc. of a tenth-normal 
solution is 0.003645, therefore, the acid solution containing 
0.003893 grams is slightly too strong. The volume to which the 
remaining 975 cc. should be made up by the addition of distilled 
water may be estimated by the following equation : 

0.003645 : 0.003893 : : 975 : X 

(975X0.003893) 

" :1024 



0.003645 

Then, 1024—975=49, or cc. of water to be added to the 975 cc. 
of the solution to make it an exact tenth-normal hydrochloric 
acid solution. 

Second method. Another method for making a tenth-normal 
hydrochloric acid solution, while probably not so accurate as 
the one described above, is often convenient to use. It is based 
on the fact that when a solution containing more than 20.2 per 
cent of hydrochloric acid in water is boiled the percentage of 



Standard Solutions 599 

acid will decrease until exactly 20.2 per cent of acid is present. 
At that point the acid and water evaporate in such proportion 
that the boiling liquid remains constant in composition, contain- 
ing very close to 20.2 per cent of the acid and having a specific 
gravity of 1.10 while any liquid remains unevaporated. Then 180 
grams of the solution will contain very close to 36.46 grams of 
hydrochloric acid, Avhich is the weight of absolute acid that is 
contained in 1000 cc. of a tenth-normal solution. 

Operation: — Place 200 cc. of distilled water in a medium tall 
beaker, and place a mark on the outside of the beaker at the upper 
surface of the water, using a pencil for marking on glass. Add to 
the water in the beaker 300 cc. of concentrated hydrochloric acid. 
Boil the liquid until so much has evaporated that its upper sur- 
face is again on a level with the pencil mark, or until the beaker 
contains approximately 200 cc. Cool the liquid to room tempera- 
ture and weigh out 180 grams of it. Dilute the 180 grams to 
1000 cc. with distilled water. The resulting solution is a normal 
solution of hydrochloric acid, and 100 cc. of it diluted to 1000 cc. 
with distilled water gives a tenth-normal acid solution. 

Standard alkaline solution: — A normal or tenth-normal alka- 
line solution may be made by standardizing an alkaline solution 
of unknown strength against the tenth-normal acid solution. 
The process may be carried out as follows : Weigh in a closed 
container about 44 grams of chemically pure caustic soda (stick 
form). Dissolve the caustic soda in distilled water and make the 
solution up to 1000 cc. This will give a solution a little stronger 
than normal. Dilute exactly 10 cc. of it to 100 cc. and titrate 
exactly 10 cc. of the tenth-normal acid solution with the diluted 
alkaline solution, using phenolphthalein as an indicator and run- 
ning the alkaline solution from a burette into the ten cc. of acid 
until exact neutrality is reached. Less than 10 cc. of the alkaline 
solution Avill be required if the work is done correctly. Next 
calculate the volume of water to add to the normal alkaline 
solution. 

Problem: Suppose it required 9.5 cc. of the alkaline solu- 
tion to neutralize 10 cc. of the acid solution. 

How much distilled water must be added to the alkaline solu- 
tion to dilute it to proper strength? 



600 Analysis of Dairy Products 

1000 — 10.0:=990, cc. of alkaline solution remaining, 

990^9.5=104. 

104X-5=52, cc. of distilled water to be added to the alka- 
line solution. 100 cc. of this standardized normal alka- 
line solution diluted to 1000 cc. will give a tenth-normal 
alkaline solution and 10 cc. of the latter should exactly 
neutralize 10 cc. of the tenth-normal acid. 

TENTH-NORMAL SOLUTION OF SILVER NITRATE. 

The molecular weight of silver nitrate is 169.89. As silver is 
a univalent element and the molecule of silver nitrate contains 
only one atom of it, 16.989 grams of pure silver nitrate in 1000 cc. 
of water solution gives a tenth-normal solution. The so-called 
chemically pure silver nitrate available at chemical supply houses 
usually contains traces of water and other foreign substances. 
When it is used in making up a standard solution allowance must 
be made for these impurities. A number of determinations have 
shown that 17.6 grams of the so-called chemically pure silver 
nitrate are usually required to make a liter of tenth-normal 
silver nitrate solution. After weighing out 17.6 grams of silver 
nitrate, dissolving it in water and making the solution up to 1000 
cc, its exact strength may be determined by checking it against 
tenth-normal hydrochloric acid as follows : 

Neutralize 25 cc. of tenth-normal hydrochloric acid with dilute 
sodium hydroxide. Add a couple of drops of 10% potassium 
chromate solution as indicator and run in, from a graduated 
burette, some of the silver nitrate solution until a drop or two 
changes the color from a light yellow to a permanent light brown 
color, which shows that all of the chlorine has combined with 
the silver and that there is present a trace of silver in excess to 
form red silver chromate. If 25 cc. of the silver nitrate solution 
is required to neutralize 25 cc. of the tenth-normal hydrochloric 
acid, the former solution is of tenth-normal strength. If less 
than 25 cc. is required the solution is too concentrated and may 
be diluted to the proper strength by calculating and adding the 
necessary volume of water. Then again check against tenth- 
normal hydrochloric acid as in the first instance. 



Acid Tests 



601 



ACID TESTS OF MILK AND CREAM. 

Since the percentage of acid in dairy products has an im- 
portant bearing on the quality and method of handling the 
products and the use to Avhich they may be put, the acid test 
becomes of importance in the dairy industry. The test is based on 
the principle that a definite weight of a given alkali unites with 
a definite M^eight of a given acid. Therefore, when the weight 
of an alkali required to neutralize the lactic acid in a definite 
Aveight of milk is known, the weight and percentage of acid in 
the milk may be readily calculated. 

Sodium hydrate is the substaince commonly used in making the 
neutralizing solution used in the acid 
test. The weight of sodium hydrate 
(NaOH) chemically equal to 1 gram of 
hydrogen is 40 grams, and 1 cc. of a 
normal solution of it contains CO-l 
gram. The weight of lactic acid 
(CsHgOy) chemically equal to one gram 
of hydrogen is 90 grams, and one cc. of 
a normal solution of it contains 0.09 
gram. Since equal volumes of normal 
solutions are chemically equal to each 
other, 0.04 gram of sodium hydrate is 
equal to 0.09 gram of lactic acid. As 
normal solutions are too concentrated 
for accurate work, solutions of one- 
tenth the normal strength are com- 
monly used. These are known as tenth- 
normal solutions. One cc. of tenth-nor- 
mal sodium hydrate solution contains 
0.004 gram and is chemically equal to 
0.009 gram of lactic acid. 
In making an acid test a known weight of the milk is neutral- 
ized with tenth-normal sodium hydrate solution using phenol- 
phthalein as an indicator. The cc. of tenth-normal solution re- 
quired are multiplied by 0.009 to obtain the weight of lactic 
acid. The product tluis obtained divided by the weight of milk 
neutralized, and tlie quotient multiplied by 100 gives the per- 
centage of acid in the milk. 




pigr. 145. 

Nafls Acidity Tester. 

Courtesy 
Louis F. Nafis, Inc. 



602 Analysis of Dairy Products 

A number of different titration tests for determining the per- 
centage of acid in milk have been devised. They aim to simplify 
the operation and remove factors that might cause error. Some 
of the more important tests follow. 

Mann's acid test: — Measure 50 cc. of milk or cream from a 
pipette into a beaker. Draw the pipette full of water and run 
the water into the beaker, add 7 or 8 drops of phenolphthalein 
indicator solution and run in from a burette tenth-normal sodium 
hydroxide solution with constant stirring until the pink color that 
develops does not disappear within 15 seconds. Calculate the per 
cent of acid by multiplying the cc. of tenth-normal alkali required 
by 0.018. One cc. of the alkaline solution neutralizes 0.018% of 
lactic acid when 50 cc. of milk is used in the test. 

The Publow Acid Test: — Measure 8.8 cc. of milk or whey into 
a white cup, add 3 or 4 drops of phenolphthalein indicator solu- 
tion and run in, from a graduated burette, tenth-normal sodium 
hydroxide solution with constant stirring until a slight permanent 
pink color develops. Each cubic centimeter of the tenth-normal 
alkali required equals O.IO*/^ of acid in the milk. The test is 
simple, accurate, and uses a very small amount of neutralizing 
solution. In testing cream weigh 9 grams into the white cup 
then proceed as in testing milk. 

The apparatus as originally devised consists of a bottle, for 
holding the alkaline solution, which has a hole drilled through 
the bottom. A brass tube is sealed in the hole and provided with 
a pinch cock which permits the alkaline solution to be drawn 
from the bottle into a burette suspended from the shelf on which 
the bottle rests. 

Farrington's Alkaline Tablet Test: — In this test alkaline 
tablets are used for making up the neutralizing solution. Each 
tablet contains indicator and sufficient alkali to neutralize .03492 
gram of lactic acid. When 5 tablets are dissolved in water and 
the solution is made up to 97 cc. one cc. of it will neutralize 0.01 
per cent of lactic acid if a Babcock pipette full of the milk, or 
18 grams are used in making the test. A tenth-normal alkaline 
solution may be made by dissolving the tablets in water at the 
rate of 24 tablets for each 100 cc. of water. As the strength of 
the tablet solution will change if held indefinitely, it is necessary 
to make up the solution on the day that it is to be used. 



TiTRATABLF, AciDlTY 603 

Operation: — For routine work in testing milk or cream, dis- 
solve 5 tablets in distilled water or rain water and make the solu- 
tion up to 97 cc. Fill a burette with the tablet solution and run it 
slowly into 18 grams of milk, or cream, that has been placed in 
a Avhite cup, until the acid is neutralized. The milk may be 
measured into the cup with a Babcock pipette, but for obtaining 
maximum accuracy in testing cream, the test sample should be 
weighed. Stir the contents of the cup while the tablet solution is 
running in. When a permanent very light pink color develops, 
all of the acid has been neutralized and no more solution should 
be run in. 

Each cubic centimeter of the solution used equals 0.01 per 
cent of acid. Thus, when 20 cc. of the tablet solution is required 
to neutralize the acid in 18 grams of milk, the per cent of acid 
present is 20X0.01=0.20 per cent. 

The Alakali Required to Neutralize One Hundred Grams of the 
More Common Dairy Products and Its Lactic Acid Equivalent. 

When phenolphthalein is used as the indicator the volume of 
tenth-normal alkali required to neutralize 100 grams of fresh 
milk may vary quite wideh^ for samples of milk from different 
sources. But rarely would less than 10 cc, or more than 25 cc. 
of the alkali be required, the average being about 16 cc. The 
amount of alkali required appears to be largely independent 
of the amount of the principal milk solids present, but it is more 
directly affected by the amount of phosphates. The richer milk 
does not always have the higher phosphate content. 

For milk and milk derivatives that have been concentrated 
or allow^ed to undergo acid development, the volume of tenth- 
normal alkali required to neutralize 100 grams may be largely 
increased as shown in the table that follows : 



604 



Analysis o? Dairy Products 



TABLE 103. 
Titratable Acidity of Various Dairy Products. 



NAME OF PRODUCT 


Approximate Average 
Percentages 


Number of cc. 

of N/10 Alkali 

Per 100 Grams 

of Product 


Acid Equival- 
ent Calculated 
as Per Cent 
Lactic Acid 




Fat 


Total Solids 


Whole milk, freshly drawn 


3.70 


12.30 


17.0 


.153 


Skim-milk, fresh 


.10 


8.90 


18.0 


.158 


Cream, fresh 


18.00 
22.00 
30.00 
40.00 


25.60 
29.25 
36.50 
45.55 


14.5 
13.8 
12.4 
10.6 


.130 


Cream, fresh 


.126 


Cream, fresh 


.111 


Cream, fresh 


.095 


Whole milk, sour, curdled upon 




heating 


3.70 


12.30 


31.0 


.280 


Buttermilk from churn — 










From sweet cream 


.50 
.30 


9.50 
9.30 


24.4 

77.7 


.22 


From ripened cream 


.70 


Buttermilk prepared from skim- 










milk using pure cultures, ten 










per cent water added 


.18 


8.10 


83.2 


.75 


Buttermilk condensed to semi- 










solid condition 


2.50 


32.50 


511.0 


4.60 


Whey from American cheddar 




cheese when drawn from curd. 


.30 


6.8 


31.0 


.28 


Evaporated milk just after con- 










densing and before sterilizing. 


8.00 


26.15 


38.8 


.35 


Evaporated milk just after 










sterilizing 


8.00 


26.15 


42.2 


.38 


Evaporated milk after being in 










cold storage one year 


8.00 


26.15 


46.6 


.42 


Condensed skim-milk plain. 










freshly prepared 


.60 


25.50 


55.5 


.50 


Sweetened condensed skim-milk. 




70.00 
72.50 


62.2 
42.2 


.56 


Sweetened condensed whole milk 


8.00 


.38 


Powdered skim-milk 


1.50 " 
28.00 


97.50 
97.50 


205.5 
144.4 


1.85 


Powdered whole milk 


1.30 


Powdered cream from cream 




testing 18 per cent fat 


70.50 


97.50 


77.7 


.70 


Powdered buttermilk 


5.00 
83.00 


97.50 

85.50 


866.6 

27.7 


7.80 


Butter 


.25 


Cheese, American cheddar after 




ripening 


34.00 


63.00 


222 2 


2.00 


Cheese, cottage, freshly prepared 


3.70 


27.20 


233.3 


2.10 


Ice cream mix, freshly prepared 


8.00 


34.00 


40.0 


.26 


Ice cream mix after aging at 










40° F. for 24 hours 


8.00 
12.00 


34.00 
36.00 


42,2 
31.1 


.28 


Ice cream mix freshly prepared. 


.25 


Ice cream mix after aging at 










40° F. for 24 hours 


12.00 


36.00 


32.2 


.27 







Milk Sediment Tksts 



605 



The Milk Sediment Test: — The sediment test is used for the 
purpose of collecting the insoluble dirt in milk. The test has 
some value as a factor in determining sanitary quality, and also 
makes it possible to demonstrate to careless dairymen the need 
for exercising constant vigilance in handling milk. The test is 
usually applied at the milk receiving station. 





Fig*. 146. Wizard Sediment Tester. Fig-. 147. Wisconsin Sediment Tester. 



There are two different forms of apparatus on the market. In 
the "Wizard" instrument the essential part consists of a cotton 
disk one inch in diameter that rests on a wire strainer held in place 
by a metal band so constructed that it can be readily adjusted to 
the top of a milk bottle. The apparatus is also provided with 
a side tube and rubber bulb for passing air into a milk bottle 
when the apparatus is attached. In applying the test, the 
apparatus, with a cotton disk in place, is adjusted to the top of 
a milk bottle, or similar container which is full of milk. The 
bottle is then inverted and one pint of the milk is allowed to pass 
through the cotton disk. The insoluble substance in the milk 
collects on the white cotton disk where it is plainly visible. The 



606 Analysis of Dairy Products 

disk may be readily removed and replaced so that testing succes- 
sive samples may proceed quickly. The disks containing the 
visible dirt may be attached to sheets of paper, dried and held 
for comparison and reference. 

The Loreiiz (Wisconsin) sediment tester is similar to the Wiz- 
ard but is connected to a copper holder for the milk. 

In the other form of apparatus some of the milk is placed in a 
test tube that is somewhat pointed at the bottom. The tube is 
then whirled for 10 minutes in a centrifuge at a speed that throws 
down the insoluble sediment and collects it in the bottom of the 
tube. The amount of sediment present may then be estimated 
and such further examination made as the case demands. 

The Alcohol Test.^ — This test is used to some extent at milk 
receiving plants and condenseries to assist in distinguishing ab- 
normal milk and milk that, after condensing, will not withstand 
temperatures high enough to insure sterilization without forming 
objectionable curd. The test is carried out by placing 2 cc. of the 
milk in a small test tube, adding an equal volume of 68 to 75 
per cent alcohol, and mixing by inverting twice while closing 
the tube with the finger. 

If a flakey white precipitate forms it is thought to indicate 
that the milk is abnormal. The amount of the precipitate and the 
size of the flakey particles forming it, indicate the degree of 
abnormality. When the mixture is shaken in a way that causes 
it to splash against the sides of the test tube for about an inch 
above the surface of the liquid, the flakey particles become at- 
tached to the wall of the test tube where their number and size 
may be noted. 

Alcoholic solutions varying in strength may be used in making 
the test, but in practical work a 68 or 70 per cent solution gives 
good results. It is important to know definitely the strength of 
the alcoholic solution, since a difference of 3 or 4 per cent in con- 
centration may have considerable effect on the result of the test. 
Experiments carried out by one of the authors indicate that 
milk which gives a negative test when fresh will give a positive 
test when between 0.015 per cent and 0.02 per cent of real acidity 
has developed, and that the result is independent of the 
"apparent" acidity of the fresh milk. 



Alcohol Milk Test 



607 



Dahlberg and Garner,^*^ using a 75 per cent alcoholic solution 
on 90 samples of milk of varying acidity, 45 of which showed 
coagulation by the alcohol test, found that 43 of the 45, when 
evaporated and sterilized at 112.8° C. (235° F.) for 30 minutes, 
showed curdiness after shaking. 

The 45 samples that gave a negative reaction with the 75 per 
cent alcohol, after evaporation and sterilization, showed only 3 
curdy samples after shaking. The results of the experiment and 
comments by the investigators follow : 

TABLE 104. 

Comparison of Alcohol and Acid Tests at Grove City Creamery. Milk con- 
centrated 2% to 1 and Sterilized at 235- F. for 30 minutes. Effect 
of Sterilization Noted After shaking for 1 minute. 





Coagulation with 75 
Per Cent Alcohol 


No Coagulation with 75 
Per Cent Alcohol 


ACIDITY 


Total 
Samples 


Effect of Sterilization 


Total 
Samples 


Effect of Sterilization 




Curdy 


Not Curdy 


Curdy 


Not Curdy 


Per cent 














0.14 to 0.15 


3 
5 


3 
5 


.0 









0.15 to 0.16 


1 





1 


0.16 to 0.17 


10 


8 


2 


9 





9 


0.17 to 0.18 


11 


11 





12 


1 


11 


0.18 to 0.19 


10 


10 





11 


1 


10 


0.19 to 0.20 


5 


5 





10 





10 


0.20 to 0.21 


1 


1 





2 


1 


1 


Total 


45 


43 


2 


45 


3 


42 



"It seems quite certain that there is some condition of raw 
milk coagulating with 75 per cent alcohol, making it impossible 
to sterilize without getting a curdy finished product, for such 
milks when evaporated and sterilized give a much firmer coagula- 
tion than those showing a negative reaction with 75 per cent 
alcohol. In some instances the coagulation, even at the lower 
temperatures used, is such that the product turns to a hard 
cheesy mass incapable of improvement with long-extended shak- 
ing. Figure 1, showing the type of curd obtained in sterilization. 



608 Analysis of Dairy Products 

indicates clearly the difference which must exist in the condition 
of milk coagulated with 75 per cent alcohol. Only 6.7 per cent 
of the samples made from milk coagulating with alcohol gave a 
soft curd, the remainder giving either a firm or a hard curd, both 
of which are as a rule difficult to shake out to give a product 
showing no curdiness. With the evaporated samples from raw 
milk not coagulating with 75 per cent alcohol 88.9 per cent gave 
either a soft curd or no coagulation at all, the remaining 11.1 
per cent giving a firm curd. The soft curds shake out very easily, 
giving a smooth-bodied product of good consistency showing no 
curdiness. ' ' 

From the results obtained in the above experiment and fur- 
ther work along somewhat similar lines the investigators drew 
the following conclusions : 

"1. The acid test as ordinarily used will reflect a portion of 
the unsatisfactory milks, but as a whole it is unreliable and inade- 
quate as a means of determining the quality of milk for conden- 
series where evaporated milk is manufactured. 

"2. There is no direct relation between the coagulation of 
milk with alcohol and its titratable acidity, but milks high in 
titratable acidity as a result of fermentation will in the large ma- 
jority of eases show coagulation with alcohol. 

3, The alcohol test shows good possibilities as a practical and 
reliable test for determining the quality of milk for condenseries 
making evaporated milk. How generally the test can be applied 
will require further investigation at other condenseries. It is 
believed that it can be used to advantage in a large majority of 
average factories." 

Ayers and Johnson^' state that "when the 68%- alcohol test is 
positive with a sample of market milk, it is evident that there is 
some change in the milk from normal. In some cases it may be 
due to an increased acidity and in consequence a change in the 
casein of the milk, due to bacterial action. In other cases, it may 
be due to a pure rennet fermentation or there may be a combina- 
tion of an acid-and-rennet fermentation. In such cases the bac- 
teria count would undoubtedly be high. However, there still 
remains to be explained the reason for a positive alcohol test in 
samples of market milk with a low bacteria count and low 
acidity." 



MiscEi^LANEous Tests 609 

HEATED MILK, PRESERVATIVE AND COLOR TESTS 

Heated Milk Test. Storcli has shown that milk when heated 
to 79° C. (174°F.) loses its power to reduce peroxides, and he has 
devised a test for distinguishing between raw milk and milk that 
has been heated to the temperature named above. He used hy- 
drogen peroxide and paraphenylenediamine hydrochloride. Cal- 
cium peroxide is quite stable and serves as well or better than 
hydrogen peroxide. To apply the test place about 5 cc. of the 
milk or cream in a test tube or other container, add from the 
point of a pen knife a little paraphenlyenediamine hydrochloride 
about the size of a kernel of wheat and an equal volume of cal- 
cium peroxide, shake thoroughly and in a very short time the 
mixture will turn to a blue color if the milk has not been heated. 
If an excess of calcium peroxide is used the milk develops a pink 
or red color. 

The same test may be used to distinguish between butter made 
from raw or pasteurized cream provided the heated cream is 
raised to 79° in the process. In applying the test, fill a test tube 
with butter and place it in water at a temperaure near 130° F. 
until the fat melts and the water and casein in the butter settle 
to the bottom. Pour off most of the fat and then complete the 
test as directed for milk. 

Evenson's Color Test^* for "Remade Milk and Cream": Pro- 
cedure for Milk. Place 25 cc. of milk in a 250 cc. beaker, add 25 
cc. of distilled water, warm to 25 or 30° C. and precipitate the 
curd by adding 4 cc. of 10 per cent acetic acid. Add 200 cc. of 
distilled water, let settle for some time, decant the supernatent 
liquid through a 166 mesh bolting cloth. Wash back into the 
beaker any curd left on the cloth and fill the beaker with water, 
allow the curd to settle and decant as before. Repeat the wash- 
ing 3 or 4 times, then transfer the curd to a 15 cm. rapid double 
filter and wash at least 3 times, filling the funnel nearly full each 
time and breaking the curd up with a glass rod to facilitate the 
washing. Remove the filter with contents from the funnel and 
squeeze out the water. Place the curd in vials of clear glass 17 
by 100 mm., add 10 cc. of 5 per cent sodium hydroxide, and, using 
a glass rod, break up and mix the curd with the liquid. 

The curd from remade milk will begin to develop a yellow 
color in about two hours ; the final observation being made after 



610 Analysis of Dairy Products 

several hours. For comparison, make in like manner a test on a 
sample of pasteurized milk. 

Procedure for Cream. Add 15 ce. of water to 15 cc. of cream 
and warm to 30 or 35° C, precipitate the curd with 2 cc. of 10 
per cent acetic acid, filter and wash. Remove most of the fat by 
washing, first with 25 to 40 cc. of 95 per cent alcohol, then with 
50 to 75 cc. of pure acetone, adding small amounts at a time and 
breaking up the curd with a glass rod after each addition. Wash 
thoroughly with water to remove acetone, drain, place in vials 
like those used for milk and add 10 cc. of sodium hydroxide. 
Make, in like manner, a comparative test on a sample of pas- 
teurized cream. 

Hener's Test for Formaldehyde. Place about 10 cc. of milk in 
a test tube or Babcock test bottle and add an equal volume of 
commercial sulphuric acid, but do not shake. A bluish violet zone 
forms where the acid comes in contact with the milk when formal- 
dehyde is present. Leonard states that pure acid will not give 
the test and advises the addition of a few drops of a 10% solution 
of ferric chloride before adding the acid. The test is very deli- 
cate, showing one part of formaldehyde in 200,000 parts of milk. 
If a large amount of formaldehyde is present the color change may 
not take place, therefore, when testing suspected milk if a nega- 
tive test is obtained, add a volume of water equal to the volume of 
milk and repeat the test. 

Hener's test does not give the color change in the presence of 
a nitrite. For this reason nitrites are sometimes added to formal- 
dehyde that is to be used surreptitiously for the purpose of pre- 
serving market milk. In making a test it is necessary to first 
remove the nitrite. In a report to the local Government Board 
(London) Monier- Williams advises the following procedure: Mix 
5 c. c. of milk with 5 c. c. of water and add 0.5 c. c. of a 10% solu- 
tion of urea, and 1 c. c. of a 5%; solution of sulphuric acid. Heat 
the mixture in boiling water for 2 minutes, cool and apply the 
test as described above for formaldehyde in milk when nitrites are 
absent. 

Vanillin also gives a color reaction similar to that produced 
by formaldehyde, therefore the test cannot be applied to cream 
flavored with vanilla. 



Miscellaneous Tests 611 

Quantitative Determination of Formaldehyde in Solution. Rob- 
inson ^" states that he has found that the method for the deter- 
mination of formaldehyde in formaldehyde solutions as outlined 
in the Journal of the Association of Official Agricultural Chem- 
ists, Numbers 1, Volume II, Part 11, page 17, gives erroneous re- 
sults. He states that the errors are probably due to loss by 
volatilization or to incomplete oxidation. For accurate determina- 
tions he recommends the following method : 

"Measure 25 c. c. of N/1 sodium hydroxide into a 200 c. c. 
Erlenmeyer flask and add 50 c. c. of hydrogen peroxide. Weigh 
out accurately 1.5 to 2.0 grams of the formaldehyde solution under 
examination, and add by means of a pipette, allowing the point 
to reach nearly to the liquid in the flask. Set aside for several 
hours, or preferably, over night. Titrate the excess sodium hy- 
droxide with N/1 acid, using purified litmus solution as an indi- 
cator. One c. c. of N/1 sodium hydroxide is equivalent to 30.02 
milligrams of formaldehyde." 

It is important to use sufficient hydrogen peroxide solution, 
and if it is not neutral it should be made so with sodium hydrox- 
ide, using the litmus solution as an indicator. 

Schmidt's Test for Sodium Carbonate: Mix 10 c. c. of milk 
with 10 c. c. of alcohol and add a few drops of a 1 per cent rosolic 
acid solution. Mix and in the presence of sodium carbonate a 
rose-red color develops. Pure milk develops a brownish-yellow 
color. 

Detection of Boracic Acid or Borax. Place about 10 c. c. of 
milk or cream iu a platinum dish, make alkaline with sodium 
hydroxide solution, evaporate to dryness and burn to an ash, add 
a few drops of concentrated hydrochloric acid to make strongly 
acid and about one cc. of water. Stir with a glass rod then place 
strips of tumeric paper in the dish so that one end of the strip 
extends up over the edge. After soaking for a few minutes re- 
move the strips and allow to dry on clean porcelain or glass at 
a gentle heat. When dry the tumeric paper will take on a char- 
acteristic deep brown-red color which will turn to a dark olive- 
green when treated with a little alkali. 

When an iuexperienced operator is making the test on a sus- 
pected sample a comparative test should be run in like manner on 
a sample of known purity. 



612 Analysis of Dairy Products 

Boracic acid or borax in butter may be detected by melting 
about 25 grams of the butter in a test tube and allowing the curd 
and water to settle to the bottom. Using a pipette, draw off most 
of the aqueous portion and place it in an evaporating dish, make 
alkaline and evaporate to about one-third of original volume, 
acidify Avith concentrated hydrochloric acid and apply strips of 
tumeric paper, completing the test as for milk. 

Salicylic Acid Test. Acidulate 50 c. c. of the milk with 
hydrochloric acid, and shake with 100 c. c. of ether. Do not shake 
vigorously enough to form an emulsion. Pour off ether ex- 
tract, evaporate nearly to dryness, add a few drops of water and 
then a little ferric chloride solution. In the presence of salicylic 
acid a deep violet color develops. 

Test for Nitrates in Milk: Since nitrates are not found in 
pure milk but are often present in water obtained from wells and 
springs, their presence in milk may indicate adulteration. The 
absence of nitrates is not proof that water has not been added 
to milk since water free from nitrates may have been added. 

Nitrates in milk may be detected as follows : Dissolve one 
part of chemically pure diphenylamine in 100 parts of chemically 
pure sulphuric acid. Place about 6 c. c. of the milk in a test tube 
and add about 3 c. c. of the sulphuric acid-diphenylamine solu- 
tion allowing it to run down the side of the tube and under the 
milk. In the presence of nitrates a blue color at the junction of 
the liquids indicates the presence of nitrates. The color may often 
be only transitory, owing to the action of the sulphuric acid on 
the milk. A very slight rotary motion usually causes the color 
to appear for an instant when nitrates are present, but the color 
quickly disappears in the liquid that is darkened by the action of 
the sulphuric acid on the milk solids. 

Stoke 's Method for Detecting- Gelatin in Milk or Cream. Dis- 
solve one part by weight of mercury in 2 parts by weight of con- 
centrated nitric acid (Sp. Gr. 1.42), and add 25 times its volume 
of water. Place 10 c. c. of this solution in a test tube together 
with an equal volume of cream, and add 20 c. c. of water, shake 
well, let stand for 5 minutes and filter. The filtrate will be cloudy 
or opalescent if much gelatin is present. Pour some of the filtrate 
into a test tube and add an equal volume of a saturated solution 
of picric acid. If the solution remains clear gelatin is absent. 



MiscELivANEous Tests 613 

Small amounts of gelatin produce a cloudiness, and larger 
amounts a stringy yellow precipitate. 

Detection of Foreign Color.-- Leach's method: Add about 5 
c. c. of acetic acid to 150 c. c. of milk in a porcelain dish and heat 
slowly nearly to the boiling point while stirring. With a stirring 
rod gather the curd into one mass or when the curd remains in 
small particles separate it from the whey by straining through a 
sieve. Press the whey from the curd, break it into small pieces 
and place in a flask, add 50 c. c. of ether, macerate thoroughly 
and allow to stand for several hours in a tightly stoppered flask, 
shaking at intervals. 

Annatto : Pour off the ether extract into an evaporating dish 
and evaporate the ether on a water bath. Make the residue alka- 
line with sodium hydroxide, and pour upon a small wet filter 
while still warm. When the solution has passed through the filter, 
wash the fat from the filter with a stream of water and dry the 
paper. If the paper is colored orange the presence of annatto is 
indicated. Confirm the test by applying a drop of stannous 
chloride solution to the paper, which in the presence of annatto 
produces a characteristic pink on the orange colored paper. 

Analin Orange. After extraction with ether the curd is per- 
fectly white from uncolored milk, or milk that has been colored 
with annatto. If the extracted curd still has distinct orange or 
yellow color, it indicates the presence of analin orange. To con- 
firm the presence of this color, place a lump of the extracted curd 
in a test tube and add a little strong hydrochloric acid. In the 
presence of analin orange, the curd turns pink at once. 

Caramel. If the extracted curd has a dull brown color the 
presence of caramel is indicated. Treat a lump of the curd in a 
test tube with strong hydrochloric acid and heat gently. In the 
presence of caramel the acid solution will gradually turn blue, 
as will also the extracted curd from uncolored milk. It is only 
when this blue coloration of the acid solution occurs in connec- 
tion with a brown colored curd, which itself does not change 
color, that the presence of caramel is indicated, as distinguished 
from the pink coloration produced at once under similar con- 
ditions by analin orange. 



614 Analysis of Dairy Products 

ANALYSIS OF BUTTER AND BUTTER SUBSTITUTES A. 0. A. C. 

METHOD. 

1. Preparation of Sample^ — Official. If large quantities of the 
butter are to be sampled, use a butter trier or sampler. Com- 
pletely melt the portions thus drawn, 100 to 500 grams, in a 
closed vessel at as low a temperature as possible. When melted, 
cool the whole, and at the same time shake the mass violently until 
it is homogeneous and sufficiently solidified to prevent the sepa- 
ration of the water and fat. Then pour a portion into the vessel 
from which it is to be weighed for analysis. The sample should 
completely or nearly fill the vessel and should be kept in a cold 
place until analyzed. 

2. Moisture — Official. Place 1.5 to 2.5 grams in a dish with a 
flat bottom having a surface of at least 20 sq. c. m. and dry at the 
temperature of boiling water until it ceases to lose weight, each 
drying being for only one hour. The use of clean dry sand or 
asbestos is admissible, and is necessary if a dish with a round bot- 
tom is employed. 

Moisture. Mojonnier Method. See Chapter VIII. 

3. Casein, Ash and Chlorin — Official. Cover the crucible con- 
taining the residue from the fat determination by the indirect 
method [see 4 (a) below] and heat gently at first, gradually 
raising the temperature to just below redness. The cover may 
then be removed and the heat continued until the contents of the 
crucible are white. The loss in weight represents casein, and the 
residue in the crucible, mineral matter. In this mineral matter, 
dissolved in water slightly acidulated with nitric acid, determine 
chlorin either gravimetrically or volumetrically. 

4. Ether Extract, (a) Indirect Method. Official. From the 
dry butter obtained in determining the water, either with or 
without the use of an absorbent, extract the fat with anhydrous 
alcohol-free ether, receiving the solution in a weighed flask. 
Evaporate the ether and dry the extract at the temperature of 
boiling water until it ceases to lose weight, the dryings not to 
exceed one hour each in duration. 

For another ether extraction method, see Mojonnier Test, 
Chapter IV. 



Salt Tests 



615 



5. Salt — Official. Weigh in a counterpoised beaker 5 to 10 
grams of butter, using portions of about 1 gram from different 
parts of the sample. Add about 20 c. c. of hot water and after 
the butter is melted transfer the whole to aseparatory funnel. 
Insert the stopper and shake for a few moments. Let stand until 
the fat has all collected on the top of the water, then draw off 
the latter into a flask, being careful to let none of the fat globules 
pass. Again add hot water to the beaker and repeat the extrac- 
tion from 10 to 15 times, using each time from 10 to 20 c. c. of 
water. The washings will contain all but a mere trace of the 





Pig". 148. Troy Salt Test Apparatus. 



sodium chloride originally present in the butter. Determine its 
amount in the whole or an aliquot of the liquid by the volumetric 
silver-nitrate method, with potassium chromate as indicator. 

Troy's Method for Determining- the Percentage of Salt in 
Butter. Place three or four onces of a representative sample of 
the butter in a wide-mouthed jar or bottle. Soften the butter 
by warming, and mix it vigorously with a spatula until it is in a 
pasty condition and is homogenous throughout. Then weigh 10 
grams into a flask and add 300 cc. of hot water (150° F.). Insert 
the stopper and shake the flask vigorously until all of the salt is 
in solution and evenly distributed. Let the flask stand for a few 
minutes until most of the fat rises to the surface, then draw a 
Babcock milk pipette full to the mark of the watery solution, and 



616 Anai^ysis op* Dairy Products 

run it into a white cup or similar container. Add 3 or 4 drops 
of a 10% solution of potassium chromate (K.Cr04), stir, and 
run in from a 10 cc. burette, tenth-normal silver nitrate solution 
with constant stirring until the color of the substance changes 
from a light yellow to a permanent light brown color. Then read 
on the burette scale the amount of standard silver nitrate solution 
used. 

Each cc. of the silver nitrate solution required equals one 
per cent of salt in the butter. 

Explanation: One cc. of tenth-normal silver nitrate solution 
contains 0.017 grams of silver nitrate and is chemically equal to 
0.00585 grams of sodium chloride. Suppose it required 2.8 cc. 
of tenth-normal silver nitrate to neutralize the salt in the 17.5 cc. 
of solution delivered from the Babcock pipette. 

0.0585X2.8=0.01638, gram of salt in 17.5 cc. of solution. 

But there are 17.14 pipette fulls in 300 cc. 
300^17.5=17.14. 
Then: 0.01638X17.14=0.280, gram of salt in 10 grams of 

butter. 
0.280-f 10=0.028, gram of salt in 1 gram of butter. 
0.028X100=2.80, grams of salt in 100 grams of butter, or 
the per cent of salt present. 

Hunziker's method-^ for determining salt in butter. (For 
factory use) : 

Equipment. — One salt tester. This is a copper container, 3>4 
inches deep, 2i/^ inches in diameter, and holding about 250 cc. It 
is equipped at its top edge with a heavy rubber ring on which 
the moisture evaporating dish is inverted, and with a lightning 
jar wire clamp for pressing the evaporated dish down on the 
rubber ring. 

One 100 cc. glass cylinder (low style). 

One 25 cc. pipette. 

One or more 150 cc. flasks (cone shape) for titrating. 

One 50 cc. burette with stand. 

One large bottle, with glass tubing and clamps to connect 
with burette, for standard silver nitrate solution. 



Salt Tests 



617 



One small bottle for potassmm chromate solution. 
Chemicals. — Silver nitrate solution containing 7.265 grams 
silver nitrate in 1000 cc. water. 
Potassium chromate solution. 





<^^> 




Tig. 149. Hunziber Salt Test Apparatus. 



Operation of test. — This test is intended to be a continuation 
of the moisture test in which an evaporating dish of a diameter of 
25^ inches is used. 

(1). At the conclusion of the moisture test fill the 100 cc. 
cylinder to the mark with warm water, temperature about 100° F., 
and pour this water into the salt tester. 

(2), Invert moisture evaporating dish over rubber ring of 
salt tester and make the dish fast by means of wire clamp. 

(3). Now shake the salt tester vigorously, giving it about 
30 shakes. This causes the salt in the evaporating dish to be 
washed out by the warm water. 

(4). Remove evaporating dish and transfer with pipette 25 cc. 
of the salt solution from the salt tester into the titrating flask. 

(5). Add 1 cc. of potassium chromate solution to the titrating 
flask and from burette slowly add silver nitrate solution until a 



618 Analysis of Dairy Products 

permanent brick-red precipitate is obtained. The titrating flask 
must be constantly and thoroughly agitated by a rotating motion 
while the silver nitrate solution is added. 

(6). If a 10-gram sample of butter is used in the moisture 
test, each cc. silver nitrate solution represents .1 per cent salt. 
Assuming that 35 cc, silver nitrate solution was used, the butter 
then contained 35/10=3.5% salt. 

(7). If the sample of butter is not exactly 10 grams, but 
somewhat more or less, the per cent of salt is readily calculated 
by dividing the cc. silver nitrate solution required, by the exact 
weight of the sample of butter. Sa.y the sample weighed 10.5 
grams and required 35 cc. of silver nitrate solution, the butter 
then contained 35/10.5=3.3% salt. 

(8). This salt test occupies about five minutes. It is exceed- 
ingly simple and accurate, when made in accordance with the 
above directions. It eliminates the weighing of the sample for the 
salt determination and it automatically washes the moisture 
evaporating cup. For uniformly reliable results the following 
precautions must be observed : 

(a). Do not slobber the melted butterfat in the evaporating 
dish, over the outside of the salt tester. The butter must stay 
inside of the periphery of the evaporating dish, when the latter 
is inverted over the tester. 

(b). Do not use water at a temperature lower, nor much 
higher, than 100° F. Water must be warm enough to melt the fat. 
If too warm it will generate pressure when shaking the tester, 
causing loss of contents. 

(c). Strap the evaporating dish down to the tester, so that 
there is no leak around the rubber ring. 

(d). Shake vigorously thirty (30) times. 

(e). Give the titrating flask the proper rotating movement 
for vigorous and continuous agitation, while the silver nitrate 
solution runs from the burette. 

(f). Stop titration when the desired color has been reached 
(brick-red). 

(g). It is necessary to give the fat time to rise in the tester 
after shaking. This requires about one minute. For this reason. 



Butter Tests 619 

the tester should be set down after shaking, and the aluminum 
cup taken off and wiped dry and gotten ready for the next 
weighing of butter. While this is done, the fat in the tester 
automatically rises to the surface, 

(h). If the edges of the evaporating dish become uneven, due 
to wear, causing the cup to leak when inverted over the rubber 
ring of the tester, invert the cup over a piece of fine emery cloth, 
and wear down the edges until even. 

10. The speed of the entire test will much depend on the prop- 
er planning and organizing of the work of both the moisture and 
the salt test, so as to avoid any waiting between steps, such as 
waiting for the evaporating dish to cool, or for the fat to rise to 
the surface in the tester. It has been found that the maximum 
speed is obtained by running the moisture and the salt tests of 
three samples together. 

11, Use only evaporating dishes without lips. 
Determination of the free fatty acids in butter A. 0, A. C. 

Method : 

Weigh 20 grams of the clear filtered fat into a flask, add 50 
c, c. of 95%' alcohol which has been neutralized with weak caustic 
soda, using phenolphthalein as indicator, and heat to the boiling 
point. Agitate the flask thoroughly in order to dissolve the free 
fatty acids as completely as possible. Titrate with tenth-normal 
alkali, agitating thoroughly until the pink color persists after 
shaking. 

Express the result as cubic centimeters of tenth-normal alkali 
required to neutralize the free acids in 100 grams of the fat, 

Halpen's test for cotton seed oil: A. 0, A. C. Method. Dis- 
solve one gram of sulphur in 100 grams of carbon disulphide and 
mix with an equal volume of amyl alcohol. Place about 8 cc, 
of the clear melted fat, or oil, in a test tube and add an equal 
volume of the above reagent. Mix and heat the test tube in a 
bath of boiling saturated salt solution for one hour. As little as 
one per cent of cotton seed oil produces an orange-red color. 

Distinguishing butter, renovated butter and oleomargarine.-- 

Examination of the melted substance: Fill a glass test tube 
or similar transparent container with the fat and heat at a 



620 Analysis of Dairy Products 

temperature of 50° C. until the fat is completely melted and the' 
water and curd has settled. The melted fat from butter will be 
clear and bright in appearance while that from renovated butter 
and oleomargarine will be cloudy and turbid. 

Vega's test. — Filter some of the fat through a hot dry filter 
into a test tube, placing the tube in boiling water for 2 minutes. In 
another large test tube place 20 cc. of a mixture of 1 part glacial 
acetic acid, 6 parts ether and 6 parts alcohol. 

Add about 1 cc. of the hot filtered fat to the reagents in the 
large test tube. Stopper the tube and shake well. Immerse in 
water at 15° C. (60° F.) and let stand 15 minutes. Pure butter 
will leave the contents of the tube almost clear while oleo- 
margarine will give a marked deposit. 

Foam test.-" — Melt in a spoon a piece of the sample about the 
size of a hickory nut over a lamp or gas flame, heating slowly 
until the fat is nearly melted, then more rapidly to boiling. With 
butter, foam forms and remains for some time, usually filling the 
spoon heaping full. On the contrary, the bubbles from oleo- 
margarine and renovated butter break almost immediately on 
forming, so that very little foam remains to obscure the surface 
of the melted fat. 

The Waterhouse test.^* — The Waterhouse test distinguishes 
between butter fat and foreign fat but does not distinguish 
between butter and renovated butter. 

Operation: Half fill a pint tin cup or beaker with skim-milk 
and heat nearly to boiling, add about 10 grams of the fat and stir 
with a small wooden splinter about the diameter of a match 
until the fat is melted. Set the cup in a pan of ice water and 
stir briskly with the splinter. Continue the stirring until the 
milk is cold enough to congeal the fat. The latter may then be 
collected into a mass by means of the splinter if the fat is from 
oleomargarine. Butter fat on the other hand, from either gen- 
uine or process butter, will not gather in a lump but will float 
quite uniformly in small particles on the surface of the liquid. 

CHEESE ANALYSIS. A. O. A. C. METHOD, 
(a). Preparation of Saniple.~When the cheese can be cut, a 
narrow, wedge-shaped segment reaching from the outer edge to 
the center of the cheese is obtained. This is to be cut into strips 



Cheese Analysis 621 

and passed through a sausage-grinding machine three times. 
When the cheese cannot be cut, samples are obtained with a cheese 
trier. If only one plug can be obtained, this should be taken 
perpendicular to the surface at a point one-third of the distance 
from the edge to the center of the cheese. The plug should reach 
either entirely through or only half-way through the cheese. When 
possible, draw three plugs — one from the center, one from a point 
near the outer edge, and one from a point half-way between 
the other two. For inspection purposes, the rind may be rejected ; 
but for investigations requiring the absolute amount of fat in the 
cheese the rind is included in the sample. It is preferable to grind 
the plugs in a sausage machine, but when this is not done they are 
cut very fine and carefully mixed. 

(b). Determination of Water. — From 2 to 5 grams of cheese 
should be placed in a weighed platinum or porcelain dish which 
contains a small quantity of porous material, such as ignited 
asbestos or sand to absorb the fat which may run out of the 
cheese. This is heated in a water oven for ten hours and weighed ; 
the loss in weight is considered as water. Or, if preferred, the 
dish may be placed in a desiccator over concentrated sulphuric 
acid and dried to constant weight. In some cases, this may re- 
quire as much as two months. The acid should be renewed when 
the cheese has become nearly dry. See Chapter VIII for method 
for determining water in cheese, using the Mojonnier Tester. 

(c). Determination of Fat. — Cover the perforations in the 
bottom of an extraction-tube with dry asbestos felt, and on this 
place a mixture containing equal parts of anhydrous copper 
sulphate and pure, dry sand to the depth of about 5 cm., packing 
loosely. Cover the upper surface of this material with a film of 
asbestos. On this are placed from two to 5 grams of the sample 
of the cheese. The tube is placed in a continuous extraction 
apparatus, and treated for five hours with anhydrous ether. The 
cheese is removed and ground to a fine powder with pure sand 
in a mortar. The mixed cheese and sand are replaced in the 
extraction-tube, the mortar washed free of all matter with ether, 
the washings being added to the tube, and the extraction is con- 
tinued ten hours. See Chapter VII for method for determining 
the fat in cheese, using the Mojonnier Tester. , 



622 Anai^ysis of Dairy Products 

(d). Determination of Nitrogen. — Make a determination of 
nitrogen by the Kjeldahl method, using about 2 grams of cheese, 
and multiply the percentage of nitrogen by 6.25. 

(e); Determination of Ash. — The dry residue from the water 
determination may be used for the ash. If the cheese be rich in 
fat, the asbestos will be saturated therewith. This may be ignited 
carefully, and the fat allowed to burn off, the asbestos acting as 
a wick. No extra heat should be applied during this operation, 
as there is danger of spurting. When the flame has died out, 
the burning may be completed in a muffle at low redness. When 
desired, the salt may be determined in the ash in the manner 
specified under butter analysis, page 614. 

(f.) Determination of Other Constituents. — The sum of the 

percentages of the different constituents, determined as above, 
subtracted from 100 will give the amount of organic acids, milk 
sugar, etc. in the cheese. 

(g). Provisional Method for the Determination of Acidity in 
Cheese. — To 10 grams of finely divided cheese, add water, at a 
temperature of 40° C, until the volume equals 105 cc. ; agitate 
vigorously and filter. Titrate portions of 25 cc. of filtrate, cor- 
responding to 2.5 gram of cheese, with standardized solution of 
sodium hydroxide, preferably one-tenth normal. Use phenol- 
phthalein as indicator. Express amount of acid as lactic. 

Troy's Cheese Moisture Test. This test provides a fairly 
rapid and accurate method for determining the percentage of 
moisture in cheese. It is practical for factory use and also 
serves well for the purpose of determining the percentage of 
moisture in butter. The high percentage of fat in butter permits 
rapid heating at a comparatively high temperature in an open 
dish without danger of loss by spattering or charring of the 
proteins until all of the moisture is driven off. But when cheese 
is treated similarly some of the solids will spatter out of the dish. 
There is not enough fat present to prevent the casein from stick- 
ing to the bottom and sides of the dish, charring and volatilizing 
some of the cheese solids. This test overcomes these difficulties 
by providing a double walled copper cup, space between the walls 



Cheesr Analysis 



62.^ 



for holding oil into which a thermometer may be inserted, thus 
providing a means of determining the temperature and permitting 
its control. A scale for weighing the cheese, and a flask for 
holding it ^hile drying and a small alcohol lamp or gas flame for 
heating the cup are necessary. The Troy Moisture Tester is illus- 
trated under Fig. 150. 

Operation: In operating the test the alcohol lamp is first 
lighted, so that the oil bath may be warming while the test 
sample is under preparation. A representa- 
tive sample of the cheese, which may be 
taken with a cheese trier and held in a glass 
stoppered sample jar, is then cut into parti- 
cles about the size of kernels of wheat with- 
out removing it from the jar. This may be 
done with an ordinary table knife that has 
had the end squared and sharpened. The 
clean dry flask is then accurately balanced 
on the scales and a 5-gram weight is placed 
in the opposite scale pan. Particles of cheese 
from the prepared sample are put into the 
flask until the scales comes to an exact 
balance. Great care should be taken to 
avoid loss of moisture from the cheese during 
the preparation of the sample. 




rig-. 150. 

Troy Moisture Tester 

for Cheese. 



With the thermometer in the oil bath 
I'egistering a temperature between 140° and 
145° C. (or between 284° and 293° F.), the flask is placed in the 
cup of the oil bath and the flat, disk-shaped cover is adjusted 
over the apparatus. The flask should remain in the bath for fifty 
minutes, the temperature being kept between 140° and 145° all 
of the time. The flask is then removed, covered, and allowed to 
cool to room temperature in a dry place. It is then weighed, 
and the quotient obtained by dividing the loss in weight by the 
original weight, multiplied by 100, gives the percentage of water 
in the cheese. The following shows the method of computation : 

Problem : Five grams of cheese were heated until the 
moisture was evaporated. The remaining substance weighed 
3.15 grams. What percentage of water did the cheese contain ? 



624 Analysis of Dairy "t^roducts 

Answer: 

5.00—3.15=1.85 

1.85-^5 =0.37 

0.37X100= 37, per cent of water in the cheese. 
A butter moisture scales with an extra 5 grams weight may 
be used for weighing out the 5 grams of cheese. If the scales 
indicate the amount of moisture in 10 grams of butter by per- 
centage graduations on its beam, or by percentage weights, then 
it is necessary to multiply by 2 the percentage indicated by such 
scales or percentage weights when only 5 grams of cheese are 
used. 

Troy's Cheese Salt Test. Place a representative sample of the 
cheese in a half pint sampling jar or similar container. Using an 
ordinary table knife, or one that has had the end of the blade 
squared and sharpened, cut the cheese sample into particles as 
small as kernels of wheat. Mix thoroughly and weigh 10 grams 
into a crucible, or into a silica or platinum dish. Dry at a 
temperature of 100° C, or a few degrees higher and then ignite 
to a gray ash, preferably in a muffle. Wash the ash from the 
dish into a flask and make up with water to 300 cc. Stir 
thoroughly to bring all of the salt into solution and to make the 
solution homogeneous. Neutralize with dilute nitric acid. Draw 
a Babcock pipette full to the mark of the solution and run it into 
an evaporating dish or white cup, add two or three drops of a 
10% solution of potassium chromate, and slowly run in tenth- 
normal silver nitrate solution from a 10 cc. burette graduated 
to 0.1 cc. until a permanent light brown color is obtained. 

Each cc. of tenth-normal silver nitrate solution required equals 
one per cent of salt in the cheese. 

THE MELTING POINT OF MILK FAT. 

As milk fat is composed of a number of different fats having 
different melting points and the percentages of these fats vary 
in different samples, the melting point of the substance is not 
sharply defined. Determinations of the melting point of samples 
from many sources by different investigators place the range of 



Melting Point of Fat 



625 



temperature within which the melting point should fall betw^een 
30 and 36.6° C. (87 and 98° F.). The solidifying points range 
between 19 and 25° C. (66 and 77° F.). 

Where the quantity of the fat permits, the simplest method for 
determining the melting point is to immerse an accurate ther- 
mometer in the partly molten and partly solid mass. 

In many instances, however, only a limited amount of the fat 
is available. Under these circumstances a drop of the melted fat 

is drawn into a thin walled glass tube 
about 1 mm. in diameter and cooled 
until completely solidified. The tube is 
then attached to the side of a ther- 
mometer, the part containing the fat 
being held on a level with the bulb. The 
thermometer and tube are then heated 
slowly in water or sulphuric acid until 
the fat begins to appear translucent, 
when the temperature is taken. The 
temperature should be taken again 
when the fat becomes nearly trans- 
parent. 

In order to avoid error due to the 
uneven heating of the immersion fluid, 
Dennis-' advises the use of sulphuric 
acid in a tube like that shown in Fig. 
151. When operating the test the tube 
may be attached to an ordinary burette 
support and sulphuric acid added until 
the tube is filled a little above the open- 
ing into the upper side arm. An 
Anschuetz thermometer with attached tube containing the slen- 
der column of solid fat is then immersed in the sulphuric acid until 
the top of the mercury column is below the opening into the upper 
side arm. The thermometer may be held in place by a burette 
support attachment, or by being fitted through a cork placed in 
the opening of the melting point apparatus. The lower arm of 
the tube is then slowly heated, by means of a flame, or electrically, 
from the lowest point to a point about midway between the 
lowest point and the perpendicular tube. The temperature 




Tig. 151. 
Meltingr Point Apparatus. 



626 



Analysis of Dairy Products 



should be taken when the fat begins to become translucent and 
molten and again when it becomes transparent. The best re- 
sults are obtained when the tube is heated electrically. To 
accomplish this it is directed that the portion, described above, 
of the tube to be treated is wrapped with a single layer of thin 
asbestos paper, and then wound with about 10 turns of michrome 
wire, No. 26, B and S gauge (about 0.016 in. in dia.). The wire 
is then covered with a layer of asbestos cement to a depth of 
about 5 mm. The melting point apparatus may be made of 
ordinary soft glass, but Pyrex glass is preferable. 

DETECTING FOREIGN FATS IN MILK FAT. 

The lower cost of most fats and oils compared with that of 
milk fat has led to their frequent substitution in a variety of 
dairy products. This practice gives special importance to 
methods used in the detection of such substitutes. The fat con- 
stants that will ordinarily enable the analyst to decide as to the 
purity of milk fat are (1) the refractive index, (2) the Reichert- 
Meissl number, and (3) the iodine number. If the evidence ob- 
tained by determining these constants is not sufficient, a more 
complete work on fat analysis should be consulted. 

The figures given in the table that follows indicate the range 
within which these constants of the edible fats and oils named 
may be expected to fall. 

TABLE 105. 

' Fat Constants. 





Refractive 
Index 
25° C. 


Eeichert-Meisel 
Number 


Iodine 
Number 


Milk fat 

Beet tallow 

Cocoa butter 


1.459 to 1.460 
1.462* to 1.465 
1.462* to 1.464 
1.452* to 1.456 
1.469 to 1.473 
1.463* to 1.467 
1.472 to 1.474 

1.467 to 1.469 

1.468 to 1.471 


25 to 34 
0.2 to 0.5 
0.2 to 0.8 
6.0 to 8.5 
0.6 to 0.8 
0.2 to 0.7 
0.7 to 0.9 
0.5 to 0.7 
0.4 to 0.6 


26 to 38 
35 to 45 
32 to 41 


Cocoanut butter 


8.0 to 9.5 


Cottonseed oil 


66 to 77 


Lard 


54 to 70 


Corn oil 


79 to 86 


Olive oil 


77 to 95 


reanut oil 


83 to 105 







* Eeading at 60° C. calculated to 25° C. 



Rkfractive Index 



627 



The Refractive Index. Determination with the Abbe Re- 
fractometer. — The double prism of the instrument is opened by 
means of the screw head, then place three or four drops of the 
liquid to be examined on the stationary prism, clamp the prisms 
together firmly. While waiting for a few minutes to permit the 
liquid to come to the temperature of the instrument, turn the 
mirror to properly light the prism. By moving the upright arm 




Tig, 152. Abbe-Zeiss Refractoiueter. 

Courtesy Arthur H. Thomas Co. 



slowly backward and forward, while looking through the sharply 
focused telescope, a light and dark portion of the field will be 
observed. The "border line" dividing the light and dark portions 
of the field is then adjusted until it rests on the point of inter- 
section of the cross hairs. The refractive index is then read 
directly to the fourth decimal by looking through the magnifier 
in the movable arm over the scale. The temperature of the instru- 
ment at the time the reading is taken should also be recorded. 
During the determination running water, held at the desired 
temperature, is allowed to flow through and control the tempera- 



628 



Analysis of Dairy Products 



ture of the instrument. The index of refraction may be taken at 
25° C, for oils and fats that are liquid at that temperature. For 
other fats, readings may be made at 40° or 60° C. 

Determinations by means of the Zeiss-Butyro-Refractometer. 

— Place 2 or 3 drops of the filtered fat on the surface of the lower 
prism. Close the prism and adjust the mirror until it gives the 
sharpest reading. If the reading be indistinct after running 
water of a constant temperature through the instrument for some 
time, the fat is unevenly distributed on the surface of the prism. 
As the index of refraction is greatly affected by temperature, 
care must be used to keep the latter constant. The instrument 
should be carefully adjusted by means of the standard fluid which 
is supplied with it. Convert the degrees of the instrument into 
refractive indices by use of the table that follows : 



TABLE 106. 
Butyro-Refractometer Readings and Indices of Refraction (A). 



Read- 
ing 


Index of 
Refraction 


Read- 
ing 


Index of 
Refraction 


Read- 
ing 


Index of 
Refraction 


Read- 
ing 


Index of 
Refraction 


40.0 


1.4524 


50.0 


1.4593 


60.0 


1.4659 


70.0 


1.4723 


40.5 


1.4527 


50.5 


1.4596 


60.5 


1.4662 


70.5 


1.4726 


41.0 


1.4531 


51.0 


1.4600 


61.0 


1.4665 


71.0 


1.4729 


41.5 


1.4534 


51.5 


1.4603 


61.5 


1.4668 


71.5 


1.4732 


42.0 


1.4538 


52.0 


1.4607 


62.0 


1.4672 


72.0 


1.4735 


42.5 


1.4541 


52.5 


1.4610 


62.5 


1.4675 


72.5 


1.4738 


43.0 


1.4545 


53.0 


1.4613 


63.0 


1.4678 


73.0 


1.4741 


43.5 


1.4548 


53.5 


1.4616 


63.5 


1.4681 


73.5 


1.4744 


44.0 


1.4552 


54.0 


1.4619 


64.0 


1.4685 


74.0 


1.4747 


44.5 


1.4555 


54.5 


1.4623 


64.5 


1.4688 


74.5 


1.4750 


45.0 


1.4558 


55.0 


1.4626 


65.0 


1.4691 


75.0 


1.4753 


45.5 


1.4562 


55.5 


1.4629 


65.5 


1.4694 


75.5 


1.4756 


46.0 


1.4565 


56.0 


1.4633 


66.0 


1.4697 


76.0 


1.4759 


46.5 


1.4569 


56.5 


1.4636 


66.5 


1.4700 


76.5 


1.4762 


47.0 


1.4572 


57.0 


1.4639 


67.0 


1.4704 


77.0 


1.4765 


47.5 


1.4576 


57.5 


1.4642 


67.5 


1.4707 


77.5 


1.4768 


48.0 


1.4579 


58.0 


1.4646 


68.0 


1.4710 


78.0 


1.4771 


48.5 


1.4583 


58.5 


1.4649 


68.5 


1.4713 


78.5 


1.4774 


49.0 


1.4586 


59.0 


1.4652 


69.0 


1.4717 


79.0 


1.4777 


49.5 


1.4590 


59.5 


1.4656 


69.5 


1.4720 


79.5 


1.4780 



(A) Winton, Conn. Agr. Exper. Sta. Rpt., 1900, Part 2, p. 143. 



Reichert-MeiseIv Number 



629 



The Reichert-Meissl Number. The Reiehert-Meissl number is 
the number of ee. of tenth-normal alkali required to neutralize 
the volatile fatty acids distilled from 5 grams of fat when they 
are set free and the operation is carried out according to specified 
conditions. The method was developed by Reichert and modified 
by Meissl. Later Leffman and Beam modified the method slightly 




rigf. 153. Distilling- Apparatus. 



by saponifying the fat in a glycerol-soda mixture in place of an 
alcoholic potash mixture. The Leffman and Beam modification 
is quite generally used at present. It is carried out as follows : 

Weigh 5 grams of the pure fat into a round bottomed flask and 
add 20 ce. of a mixture made by placing 10 cc. of a 50 per cent 
caustic soda, water solution, in 90 cc. of glycerine. Heat the 
contents of the flask over a small flame, with constant shaking, 
until the water is boiled off and the mixture which on boiling had 
a clouded appearance, becomes clear. Add 135 cc. of water 
slowly, to prevent foaming and a pinch of pumice stone powder, 
or a few pieces of pumice stone to prevent bumping during distil- 
lation. Add 5 cc. of dilute sulphuric acid (200 cc. of concentrated 
sulphuric acid in 1000 cc. of water). Connect the flask at once 
to a condenser, shake to mix the acid with the solution and heat 
to distill off the volatile acids. Distill off 110 cc. at a rate that 
will yield that volume in 30 to 40 minutes. Filter the distillate 
through a dry filter and titrate 100 cc. of it with tenth-normal 
alkali solution. The number of cc. of tenth-normal alkali used 
multiplied by 1.10 equals the Reichert-Meissl number. 



630 Analysis of Dairy Products 

The Reichert-Meissl number for milk fat is usually between 
25 and 32, for cocoanut oil between 6 and 8, and for most other 
fats and oils less than 1.5. 

lodin Absorption Number of Fat and Oils. — The capacity of 
fats and oils to absorb iodin is sometimes used to advantage for 
the purpose of identifying them or determining their purity. The 
percentage of iodin that a given fat or oil will absorb under 
specified conditions is called its iodin number. A method for 
treating fats and oils with iodin was developed by Hubl.-*^ It was 
improved and shortened by Hanus and is the method usually 
employed. The A. 0. A. C. has adopted it as follows : 

Hanus Method. — Official. — Reagents. — (a) Hanus iodin solu- 
tion. — Dissolve 13.2 grams of pure iodin in one liter of glacial 
acetic acid (99.5 per cent) which shows no reduction with 
dichromate and sulphuric acid. Add enough bromin to double the 
halogen content as determined by titration (3 cc. of bromin are 
about the proper amount). The iodin may be dissolved by heat- 
ing, but the solution should be cold when the bromin is added. 

A convenient way to prepare the Hanus solution is as follows : 
Measure 825 cc. of acetic acid which has shown no reduction by 
the dichromate test and dissolve in it 13.615 grams of iodin with 
the aid of heat. Cool and titrate 25 cc. of this solution against the 
N/10 sodium thiosulphate. Add 3 cc. of bromin to 200 cc. of 
acetic acid and titrate 5 cc. of the solution against the N/10 
sodium thiosulphate. Calculate the quantity of bromin solution 
required exactly to double the halogen content of the remaining 
800 cc. of iodin solution as follows : 

A= — in which 
C 

A^cc. of bromin solution required. 

Br=800 X the thiosulphate equivalent of 1 cc. of iodin 

solution, 

C=the thiosulphate equivalent of 1 cc. of bromin solution. 

Example: — 136.15 grams of iodin are dissolved in 8250 cc. of 
acetic acid. 30 cc. of bromin are dissolved in 2000 cc. of acetic 
acid. Titrating 50 cc. of the iodin solution against the standard 
thiosulphate shows that 1 cc. of the iodin solution equals 1.1 cc. of 



Iodinb; Numbe;r 631 

the thiosulphate (0.0165 gram of iodin). Titrating 5 cc. of the 
bromin solution shows that one cc. of the bromin solution equals 
4.6 cc. of the thiosulphate. Then the remaining quantity of 
bromin solution required to double the halogen content of the 

remaining 8200 cc. of iodin solution is equivalent to ' 

4.6 

or 1961 cc. Upon mixing the two solutions in this proportion, a 
total volume of 10161 cc. is obtained, containing 135.3 grams of 
iodin. In order to reduce this solution to the proper strength 
(13.2 grams iodin per liter), 10.161X13.2=134.1; 135.3—134.1= 

1 o f ■ A . ■ 1.2X1000 _^ „ 

1.2 grams ot lodm present m excess, or — =91 cc. ot 

13.2 

acetic acid which must be added. 

(b). N/10 sodium thiosulphate solution. — Prepare a solution 
containing 24.82 grams of sodium thiosulphate (Na2S20;55H20) 
in water and dilute to 1 liter. Standardize this solution as 
follows : Place in a glass stoppered flask 20 cc. of the N/10 
potassium dichromate and 10 cc. of the 15 per cent potassium 
iodide solution. Add 5 cc. of strong hydrochloric acid. Dilute 
with 100 cc. of water and allow the N/10 sodium thiosulphate to 
flow slowly into the flask until the yellow color of the liquid has 
almost disappeared, add a few drops of starch indicator and, 
with constant shaking, continue to add the N/10 sodium thio- 
sulphate until the blue color just disappears. 

(c). Starch indicator: — Mix about 0.5 gram of finely pow- 
dered potato starch with cold water to a thin paste ; pour into 
about 100 cc. of boiling water, stirring constantly, and discon- 
tinue heating immediately after the paste is added. 

(d). Potassium iodid solution. — Dissolve 150 grams of potas- 
sium iodid in water and dilute to 1 liter. 

(e). N/10 potassium dichromate. — Dissolve 4.903 grams of 
potassium dichromate in water and dilute to 1 liter. The strength 
of this solution should be checked against pure iron. 

Determination. — ^Weigh about 0.500 gram of fat, or 0.250 gram 
of oil (0.1 — 0.2 gram in the case of drying oils which have a very 
high absorbent power), into a 500 cc. glass-stoppered flask or 
bottle. Dissolve the fat or oil in 10 cc. of chloroform. Add 25 cc. 



632 Anai^ysis of Dairy Products 

of the Haniis iodin solution and alloAv to stand for 30 minutes, 
shaking occasionally. 

This time must be adhered to closely in order to obtain good 
results. The excess of iodin should be at least 60 per cent of the 
amount added. Add 10 cc. of the 15 per cent potassium iodid solu- 
tion, shake thoroughly and then add 100 cc. of water, washing 
down any free iodin that may be found on the stopper. Titrate 
the iodin with N/10 sodium thiosulphate, adding the latter grad- 
ually, with constant shaking, until the yellow color of the solution 
has almost disappeared. Add a few drops of the starch indicator 
and continue the titration until the blue color has entirely dis- 
appeared. Toward the end of the titration, stopper the bottle 
and shake violently, so that any iodin remaining in solution in 
the chloroform may be taken up by the potassium iodid solution. 
Conduct two blank determinations along with that on the 
sample. The number of cc. of the sodium thiosulphate solution 
required by the blank less the amount used in the determination 
gives the thiosulphate equivalent of the iodin absorbed by the 
fat or oil. Ascertain the iodin number by calculating the per cent 
by weight of iodin absorbed. 

ESTIMATION OF MILK FAT IN MILK CHOCOLATE. A. 0. A. C— 
TENTATIVE METHOD. 

Estimate the amount of milk fat in milk chocolate from the 
following formula based on a Reichert-Meissl number of 0.5 for 
cocoa butter : 

24A+0.5B 

C= p in which 

5 

A=grams of butter fat in 5 grams of mixed fat, 
B=5 — A= grams of cocoa fat in 5 grams of mixed fat, 
C=Keichert-Meissl number of extracted fat. 

From which the 

C— 0.5 
Weight of butter fat in 5 grams of mixed fat=r — j-Tj— and the 

C— 0.5 

Per cent of butter fat=per cent of total fatX qq r 



I 



Tests for Thickeners . 633 

DETECTING GUMS, GELATINIZING AGENTS AND THICKENERS. 
In recent years a number of substances of colloidal nature 
have been used to give apparent "body" to a wide variety of 
food products. Most of them are able to absorb relatively large 
amounts of water and when mixed with diluted food emulsions 
impart properties that simulate the richness of the genuine 
product. Among the substances used are gelatin, sucrate of lime, 
gum tragacanth, gum arabie (acacia), agar-agar, starch, dextrin, 
glucose, and pepsin. Methods for detecting their presence in 
foods and for identifying them have been developed and while 
not wholly satisfactory serve their purpose fairly well. 

Patrick's Method for Detecting* Thickeners. — Add 25 cc. of 
water to 50 cc. of the sample and heat to boiling to dissolve 
thickeners that may be present, add 2 cc. of 10 per cent acetic 
acid, heat again to boiling and add 3 heaping tablespoonfuls of 
kieselguhr, mix thoroughly and pass, without delay, through a 
plaited filter. Add 12 cc. of 95% alcohol to 3 cc. of the clear 
filtrate and mix. This precipitates any of the milk proteids 
remaining, also the gums and some of the gelatin if much is 
present. To dissolve the milk proteids add 3 cc. of a mixture 
containing 5 cc. of concentrated hydrochloric acid in 95 cc. of 
95% alcohol. If a clear liquid is obtained no gums or vegetable 
jellies are present, and turbidity or a precipitate does not 
necessarily indicate the presence of a thickener, as it may result 
from the use of eggs or the gelatin used in ice cream as a 
stabilizer. Add 3 cc. of water, if the mixture is turbid at this 
dilution any precipitate due to gelatin or eggs will be dissolved, a 
stringy and cohesive precipitate, especially after shaking, shows 
the presence of gum tragacanth, while agar-agar and other vege- 
table thickeners give a finely flocculent precipitate devoid of 
stickiness. When sour cream containing no thickeners is tested 
an insoluble precipitate may form and which does not dissolve 
when water is added. By adding formaldehyde to the sample 
while it is sweet, it appears that the formation of such a precipi- 
tate may be avoided. 

Cong-don's Method-" for Detecting Thickeners and Similar 
Agents in Foods. — By this method the thickening materials are 
separated into six groups on the basis of reagents used. The 
reagents are added to the water soluble solutions of the materials 



634 • Analysis of Dairy Products 

to obtain the reactions. While specific directions for applying 
the method to dairy products are not given in the original article 
the following table should be of assistance in identifying the 
different substances. — 

"Group 1. — Group reagent — Iodine solution. 

Blue coloration indicates starch. (Sometimes green apples made into 

jelly will give traces of starch.) 
Purple coloration indicates Amylo-dextrin. 
Red coloration indicates Erythro-dextrin. 
No coloration may indicate neither starch nor dextrin, but may be Achro- 

dextrin. 

Group II. — Group reagent — Million's or Stokes' reagent (acid nitrate of 
mercury). 
Mixture, after shaking substance in solution with reagent, is cloudy, 

Yellow precipitate with picric acid solution indicates Gelatin. 
Drop of this reagent. Gelatinous precipitate, soluble in excess of this 

reagent, indicates Acacia. 
A slight white cloudy precipitate may indicate either Agar -agar or 

Tragacanth or both (test for Tragacanth as in gi'oup IV). 

Group III.- — Group reagent — Concentrated solution of sodium borate. 

A white gelatinous precipitate indicates either Agar -agar or Acacia or 

both. 
Acacia will give a gelatinous, opaque white precipitate with solution 

of basic lead acetate. 
Acacia may be further tested for as in Group II or Group IV or by 

adding a solution of tannin which gives a bluish black coloration. 

Group IV. — Group reagent — Solution of sodium hydrate. 

A brownish yellow color on heating indicates Tragacanth. 

A white cloudy precipitate indicates Acacia. 
Group V. — Group reagent — Solution of mercuric chloride. 

A slight turbidity may indicate Dextrin. 

A white precipitate may indicate Albumin and Gelatin. 

Group VI. — Group reagent — Schweitzer's reagent (solution of cupra-ammonia). 

If a concentrated water solution of the unknown is treated with this 

reagent and placed on glass slide under microscope, a delicate 

framework of cupric pectate is evident, showing a pectin of fruit 

or vegetable origin present." 

Cook and Woodman's Method-* for the Detection of Vegetable 
Gums in Food Products. — In this method the tests are applied to 
the gums after they have been separated, in a relatively pure 
condition, from 50 to 200 grams of the sample as the ease may 



Tests for Thickeners 



635 



require. The proteins in the food mixture are precipitated by 
adding acetic acid and tannin, heating and filtering, then the 
gums are precipitated from the filtrate by the addition of acetone. 
The filtrate contains the sugars and other acetone soluble ma- 
terial. Soluble phosphates, derived from sources like milk, are 
removed by an extra precipitation with ammonia. Finally the 
guqis are redissolved and precipitated relatively pure by alcohol. 

In order to use the method successfully, before making a test 
on an unknown, the analyst should become familiar with the 
appearance and characteristic properties of the various gum 

TABLE 107. 
The Separation of Gums. 



A — Elimination of 
Proteins. 



1 — Dilute sample to suit- 
able c o n c e n tration 
with water, add 5 cc. 
dilute acetic acid and 
35 cc. of 10 per cent 
tannin solution, and 
heat mixture for 20 
to 30 minutes. Centri- 
fuge and filter. Dis- 
card precipitate. 

Note — Casein, coagulable 
proteins, and some of 
the gelatin precipi- 
tated. Fats and other 
insoluble substances 
included in precipi- 
tate. 

2 — Add 40 to 50 cc. more 
tannin solution to fil- 
trate from Al and 
heat for a short time. 
Centrifuge and filter. 
Discard precipitate. 

Note — Remainder of gel- 
atin and soluble pro- 
teins precipitated. 



B — Separation of Gums 

and Dextrin from 

Sugars. 



1 — Treat clear filtrate 
from A2 with twice 
its volume of acetone. 
Centrifuge and filter. 
Discard filtrate. 
Wash precipitate 
twice with acetone. 

Note — Precipitate in- 

cludes gums and dex- 
trin. No precipitate 
shows absence of 
gums, dextrin, and 
milk solids. 

3 — Dissolve precipitate 
from Bl in 50 cc. of 
warm water slightly 
acidified with acetic 
acid and add 10 cc. of 
ammonia (sp. gr. 
0.90). Centrifuge and 
filter. Discard pre- 
cipitate. 

Note — Calcium phos- 

phate from milk 
solids precipitated. 



-Isolation of Pure 
Gum Substance. 



Add acetic acid to filtrate 
from B2 until slightly 
acid. Add alcohol, one 
volume at a time, un- 
til a well defined pre- 
cipitate appears. 

Note — Gums and dextrin 
precipitated in a fair- 
ly pure condition. No 
precipitate with 5 
volumes of alcohol in- 
dicates absence of 
gums and dextrin. 



636 



Analysis of Dairy Products 



precipitates by working on their solutions. The procedure is 
summarized in the following table: 



TABLE 108. 
Identification of Gums. 



Approximate Volumes 

of Alcohol Necssary 

for precipitation 


Characteristic 

Appearance of 

Gum Precipitate 


Characateristics 
of Gum Precipitate 
After Standing for 
Some time in Air. 


Vols. Al- 
cohol 


Vol. Gum 
Solution 


Agar ..3-4 
Arabic ... 2 

Indian .3-3 

Traga- 
canth ... 2 

Dextrin . . 3 


1 
1 

1 

1 

1 


Finely divided white pre- 
cipitate; settles very 
slowly. 

Wliite flocculent precipi- 
tate; settles quickly; 
neither sticky nor co- 
herent. 

Stringy precipitate; be- 
comes very coherent 
after settling. 

Coherent, jelly-like mass; 
floats in clots in upper 
part of solution. 

■Wliite, fine precipitate, 

settles slowly; very 

sticky. 


Usually remains soft and 
non-coherent. 

Becomes dry and powdry. 

Becomes dark colored; 
tough coherent layer. 

Flattens down, becoming 
a semi-transparent co- 
lierent layer. 

Tends to become hard on 
long standing. 



It is claimed that, by the above procedure, amounts of gum 
as small as 0.1 per cent can be separated from ordinary food 
mixtures, but some gums are more readily detected than others. 
Tragacanth is easier to detect than either gum arable or agar. 
Where the ratio of protein, and possibly some other precipitable 
matter is large there is danger of the gums bing carried down 
mechanically and lost. 

Where more than one gum is present, and in mixtures con- 
taining pectin and commercial glucose, the identification of the 
gum is made more difficult. 

Sucrate of Lime in Milk and Cream.— Sucrate of lime (visco- 
gen) is sometimes added to cream in order to increase the 
viscosity, a quality that indicates richness. Determinations of 



Lime De;terminations 637 

(1) the presence of sucrose, (2) the alkalinity of the water-soluble 
ash, (3) the alkalinity of the insoluble ash, and (4) the lime 
content may assist in detecting its presence. 

Sucrose may be detected by means of Lythgoe's modification-" 
of Baier and Neuman's test. The test is made according to the 
following directions : 

Add 10 cc. of a 5 per cent solution of uranium acetate to 25 cc. 
of the sample, shake thoroughly, let stand for five minutes and 
filter. To 10 cc. of the filtrate (or all of it if less than 10 cc.) add 
a mixture of 2 cc. of saturated ammonium molybdate solution and 
8 cc. of dilute hydrochloric acid (1 cc. of 25 per cent acid in 7 cc. 
of water) and place in a water bath at a temperature of 80° C. 
for 5 minutes. The solution will have a prussian blue color if 
sucrose is present. A comparative test should be run in like 
manner on a pure sample. The latter will sometimes give a pale 
blue color. 

Alkalinity and Calcium Determinations. — Weigh into a plati- 
num dish 25 grams of the sample, evaporate to dryness in a water 
bath, char and burn at a temperature so low that the fat will 
scarcely flame until it is burned off, then at a little higher 
temperature but not above a barely preceptible red until all of 
the carbon has disappeared and the ash is almost white. Cool in 
a desiccator and weigh. 

To determine the alkalinity of the soluble ash add 25 cc. of 
water and heat nearly to boiling, filter through an ashless filter, 
wash with 25 cc. of hot water, dry the filter and contents and burn 
to a white ash. Weigh to obtain the insoluble ash, and subtract 
its weight from the total ash to obtain the weight of the soluble 
ash. 

To determine the alkalinity of the water-soluble ash add 20 cc. 
of N/10 hydrochloric acid to the filtrate containing the soluble 
ash, heat nearly to boiling to expel carbon dioxide, cool, add a 
few drops of phenolphthalein indicator solution and neutralize 
the excess of hydrochloric acid with N/10 alkali. Determine the 
cc. of N/10 hydrochloric acid to neutralize the soluble ash, 
then calculate and record the result on the basis of 100 grams of 
the sample. 

To determine the alkalinity of the insoluble ash place 25 cc. 
of N/10 hydrochloric acid in the dish containing it and heat 



638 Analysis of Dairy Products 

cautiously nearly to boiling, cool and neutralize the excess of 
hydrochloric acid with N/10 alkali, using phenolphthalein as 
indicator. Calculate the cc. of N/10 acid required to neutralize 
the ash and report the result as in the determination for the 
alkalinity of the soluble ash. 

The total ash alkalinity of 100 grams of cream containing 
between 25 and 33 per cent of fat requires between 14 and 20 cc. 
of N/10 acid calculated to 100 grams of sample. 

To determine the calcium. — Mix the neutral liquids from the 
soluble and insoluble ash, add 20 cc. of dilute hydrochloric acid, 
neutralize with ammonia, add one gram of ammonium chloride 
and an excess of ammonium oxalate. Boil for three or four 
minutes, filter through an ashless filter and wash with water. 
Dry the filter with the precipitate, burn the filter, allowing the 
precipitate and ash to fall into a weighed platinum crucible. Heat 
gently at first and then for 10 minutes at a very dull red. Avoid 
over heating, as some of the calcium carbonate may be converted 
to the oxide. Cool in a desiccator and weigh. From the weight 
of calcium carbonate obtained calculate the weight of calcium 
oxide. 

The maximum amount of calcium oxide in milk should not 
exceed 0.212 per cent. In cream, as the percentage of fat in- 
creases, the percentage of calcium oxide decreases. The maximum 
percentage of calcium oxide that is likely to be obtained from 
pure cream may be calculated by applying the formula: 

(100— F\ 
— fr\(\ — / 

F=the per cent of fat in the cream. 

A METHOD FOR ANALYZING SALT.^ 

Tests for Insoluble Matter. — After sampling well reduce the 
salt to a fine powder, and put into a glass-stoppered bottle. 
"Weigh out 10 grams of this powder and dissolve in a beaker by 
digestion Avith hot water and filter the solution into a 500 cc. 
graduated flask. Wash the residue thoroughly, taking care that 
the residue contains insolubles only and not grains of the slowly 
soluble calcium sulphate. Fill the flask up to the mark with 



Sai,t Analysis 639 

distilled water, mix well and set aside for later determina- 
tions. Ignite and weigh the insoluble residue. This weight multi- 
plied by 100 and divided by the weight of the sample (10 grams) 
gives the per cent of insoluble matter. 

Test for Calcium: — Remove 150 cc. of the salt solution from 
the 500 cc. flask with a pipette and add a small quantity of 
ammonium chloride and a slight excess of ammonium hydroxide. 
The solution should be clear at this point, if not, more ammonium 
chloride should have been added. A considerable excess of 
ammonium oxalate solution is now added and the solution allowed 
to stand for some time, after which it is filtered and the residue 
washed well. The precipitate of calcium oxalate contains a slight 
amount of magnesium at this point and for a complete separation 
must be redissolved with hydrochloric acid, made alkaline with 
ammonium hydroxide and reprecipitated with ammonium oxalate. 
The calcium oxalate precipitate is then dissolved from the filter 
paper with 150 cc. dilute sulphuric acid and the paper washed 
well. About 6 or 8 cc. of strong sulphuric acid is then added and 
the solution warmed to 60^ centrigrade and titrated with potas- 
sium permanganate solution to a slight pink color. The solution 
should be stirred during the titration. In order to obtain the 
percentage of calcium without calculation the potassium per- 
manganate solution should be made up by dissolving 0.5254 gram 
of chemically pure potassium permanganate in one liter of dis- 
tilled water accurately measured. It is best to make up at least 
five liters of this solution and use an automatic burette if very 
much work is to be done. Each 10 cc. of this solution will be 
equal to 1% calcium with the above method. 

The potassium permanganate solution should be kept in a 
brown bottle or a bottle painted black. It is well to check the 
solution from time to time against a weighed sample of chemically 
pure sodium oxalate. Thirty cubic centimeters of the potassium 
permanganate solution will consume 0.03342 gram of the sodium 
oxalate. It is easier to weigh a larger quantity of the salt and 
several checks should be made at a time, so it is best to dissolve 
0.3342 gram of sodium oxalate in 500 cc. of distilled water and 
take several portions of 50 cc. each. Titrate this with the 
permanganate solution after adding 5 or 6 cc. of strong sulphuric 
acid and warming to 60° Centigrade. If the permanganate is 



640 Analysis of Dairy Products 

found to be too weak it can be strengthened by adding a little of 
a stronger solution. 

Test for Magnesium : — The combined filtrates from the calcium 
determination are acidified, evaporated to about 100 cc, 30 cc. 
of strong ammonia and 25 cc. of 10% solution of sodium arsenate 
added. This is best done in an Erlenmeyer flask, so that the 
solution may be vigorously shaken after the reagents have been 
added. The precipitate is filtered off, washed with the least 
possible amount of dilute ammonia, dissolved in 25 cc. dilute 
sluphuric acid (1 to 4) into the original flask. The filter is 
washed with 50 cc, hot water and 10 cc. sulphuric acid (1 to 1) 
added. After cooling, 3 to 5 grams of potassium iodide are added, 
the solution allowed to stand for five minutes, then the liberated 
iodine titrated with sodium thiosulphate solution to a faint 
straw color. A few cubic centimeters of starch solution are then 
added and the titration completed to a colorlessness. The 
standard sodium thiosulphate solution should be made up of 
6.7863 gm. of chemically pure sodium thiosulphate crystals 
(Na2S203.5HoO.) per liter. Ten cubic centimeters of this 
solution is equal to 1% magnesium. Standardize this solution 
against 50 cc. samples of a solution of 0.4942 gm. of chemically 
pure magnesium sulphate crystals in 500 cc. of distilled water 
treated as for the analysis of magnesium. It should take exactly 
30 cc. of the standard sodium thiosulphate solution to titrate these 
samples. The starch indicator solution is made by mixing 1 gm. 
of starch to a paste in a little cold water and then gradually 
pouring this into 200 cc. of boiling water. This solution should 
be boiled a little and put into a glass stoppered bottle with a few 
drops of chloroform when cool. 

Test for Sulphate. — A sample of 100 cc. of the original salt 
solution is transferred to a 250 cc. beaker, made very slightly 
acid with hydrochloric acid, heated to boiling and an excess of 
barium chloride solution containing about 100 gms. of the salt per 
liter is added while rapidly stirring the solution. After allowing 
to stand a few moments the barium sulphate is filtered off on an 
ashless filter and M^ashed well with water. The filter containing 
the precipitate is then placed in a weighed porcelain or platinum 
crucible and ignited, cooled and weighed. 



Vanii<i.a Analysis 641 

Other Impurities. — Potassium, bromine and iodine are present 
in rock salt and brines in very small quantities, if present at all, so 
there is no need, except in the rarest cases, to analyze the salt 
or brine for them. It is customary to regard the balance of the 
material as sodium chloride or common salt. 

VANILLA EXTRACT. 

Pure vanilla extract is made from the vanilla bean. There 
are several varieties of this bean and the different varieties vary 
quite widely in flavoring value. The choicest extract is obtained 
from beans grown in Mexico. The Tonka bean, which is not a 
variety of the vanilla bean, is commonly used in making imitation 
or substitute vanilla flavoring. The Tonka bean contains cou- 
marin, which subtance is not present in the vanilla bean. By 
extracting the Tonka bean and by mixing synthetic vanillin and 
other substances, such as caramel, prune juice, resinous material, 
glycerol and alcohol, a flavoring may be made that resembles pure 
vanilla extract, but the difference can be detected by the analyst. 
The pure extract possesses a delicacy of flavor and subtlety of 
aroma that cannot be obtained in the substitute or artificial 
product. The presence of coumarin, abnormal amount or de- 
ficiency of vanillin and resinous material, and peculiar reactions 
of the latter assist in distinguishing the fictitious from the pure 
extract. 

The pure vanilla extract is usually made by cutting the vanilla 
beans into small pieces, then crushing them, adding sugar, alcohol 
and water ; macerating the mixture for several hours, then placing 
it in a percolator and extracting it with 50 per cent alcohol. 

Vanilla extract of U. S. Standard quality is the flavoring 
extract obtained from the vanilla bean with or without sugar or 
glycerine and contains in 100 cc. the soluble matters from not 
less than 10 grams of vanilla bean. 

EXAMINATION OF VANILLA EXTRACT. 

Total Solids, A. 0. A. C. method. — Official. Digest (pure 
quartz sand with strong hydrochloric acid, wash, dry and ignite. 
Preserve in a stoppered bottle. 

Place 6-7 grams of the prepared sand and a short stirring rod 
in a flat bottomed dish. Dry thoroughly, cool in a desiccator and 



642 Analysis of Dairy Products 

weigh. Then add 3-4 grams of the extract, mix with the sand, 
dry in a water oven at the temperature of boiling water for 8-10 
hours, stirring at intervals of an hour, cool in a desiccator and 
weigh. Stir, heat again for an hour, cool and weigh. Repeat the 
heating and weighing until the loss of water in an hour is not 
greater than 3 mg. 

Alcohol determination: Place 25 cc. of the sample in a dis- 
tilling tiask and add 25 cc. of water. Distil almost 25 cc. and make 
up to 25 cc. with water. Determine the specific gravity of the 
distillate at 15.6° C. Obtain from an alcohol table the grams per 
100 cc. 

Vanillin and coumarin: A. 0. A. C. Method — Official. (This 
method is not applicable to concentrated vanillin and coumarin 
preparations in which the amount of vanillin and coumarin 
present in 50 cc. exceeds the quantity dissolved by 100 cc. of water 
at 20° C. In such cases employ a smaller amount of sample and 
dilute to 50 cc.) 

Preparation of solution : Measure 50 cc. of the extract at 20° 
C. into a 250 cc. beaker with marks showing volumes of 80 and 
50 cc, dilute to 80 cc. and evaporate to 50 cc. on a water bath kept 
at 70° C. or below. Dilute again to 80 cc. and evaporate to 50 cc. 
Transfer to a 100 cc. flask, rinsing the beaker with hot water ; add 
25 cc. of 8 per cent neutral lead acetate solution ; make up to the 
mark with water, shake and allow to stand 18 hours (overnight) 
at 37°-40° C. Decant into a small, dry filter, reserving the 
filtrate for the determination of vanillin and coumarin, the lead 
number, and the residual color. 

Determination: Transfer a 50 cc. aliquot of the filtrate to a 
separatory funnel and extract with four successive portions of 
ether (previously washed twice with an equal volume of water 
to remove alcohol). Wash the combined ether solutions four or 
five times with 2 per cent ammonium hydroxide solution (2 per 
cent NHo by weight), using 10 cc. the first time and 5 cc. there- 
after, and reserve the ether solution for the determination of 
coumarin. Slightly acidify the combined ammoniacal solutions 
with hydrochloric acid ; cool and extract in a separatory funnel 
with four portions of washed ether, using about 40 cc. altogether. 
Evaporate the ethereal solutions at room tempei'ature, dry over 



Vanilla Analysis 643 

sulphuric acid and weigh. If the residue is considerably dis- 
colored or gummy, re-extract in the dry state with boiling pe- 
troleum ether (b. p. 40° C. or below) not less than 15 times; 
evaporate the solvent, dry and weigh. The residue should now 
be white, crystalline vanillin, with a melting point of approxi- 
mately 80'' C. A small amount of this residue, dissolved in 2 
drops of concentrated hydrochloric acid, should develop a pink 
color upon the addition of a crystal of resorcin. 

Evaporate at room temperature the original ether extract of 
the sample, from which the vanillin has been removed by means 
of ammonium hydroxide, and dry over sulphuric acid. The resi- 
due, if pure coumarin, should melt at approximately 67° C. and 
should respond to Leach 's test for coumarin as follows : A small 
portion of the residue, dissolved in not more than 0.5 c. c. of hot 
water, should yield a brown precipitate upon the addition of a 
few drops of N/10 iodin. This precipitate finally gathers in 
green flecks, leaving a clear, brown solution. The reaction is espe- 
cially marked if the reagent is applied with a glass rod to a few 
drops of the solution on a white plate or tile. 

Lead Number: A. 0. A. C. — Official. To a 10 cc. aliquot of the 
filtrate from the lead acetate precipitate, as obtained under 
"Preparation of solution," add 25 cc. of water, 0.5-1.0 cc. of 
sulphuric acid, and 100 cc. of 95 per cent alcohol by volume. 
Let stand over night, filter on a Gooch crucible, wash with 95 per 
cent alcohol, dry at a moderate heat, ignite at low redness for 
three minutes, taking care to avoid the reducing flame, and weigh. 
Conduct a blank determination employing water containing 4 or 
5 drops of glacial acetic acid in place of the sample. The lead 
number is calculated by the following formula : 

100X0.6831 (S— W) 
P= — ^ -=13.66 (S— W) in which 

D 

P^rlead number (grams of metalic lead in the precipitate ob- 
tained from 100 cc. of the sample) ; 

S=:grams of lead sulphate corresponding to 2.5 cc. of the lead 
acetate solution as determined in a blank analysis ; and 

W=r grams of lead sulphate obtained in 10 cc. of the filtrate from 
the lead acetate precipitate, as obtained under "Preparation 
of solution." 



*^44 Analysis of Dairy Products 

Vanilla Resins 

Qualitative Test: A. 0. A. C— Tentative. Place 50 cc. of the 
extract in a glass dish and evaporate the alcohol on a water bath. 
When the alcohol is removed, make up to about the original 
volume with hot water. If alkali has not been used in the manu- 
facture of the extract, the resins will appear as a floculent red to 
brown residue. Acidify with acetic acid to free the resins from 
the bases, separating the resins completely and leaving a part de- 
colorized, clear, supernatant liquid after standing a short time. 
Collect the resins on a filter, wash with water and reserve the fil- 
trate for further tests. 

Place a portion of the filter with the attached resins in a few 
cc. of dilute potassium hydroxide solution. The resins are dis- 
solved, giving a deep red solution ; acidify, and the resins are 
precipitated. 

Dissolve a portion of the resins in alcohol. To one portion add 
a few drops of ferric chloride solution ; to another portion, hydro- 
chloric acid ; neither produces any marked change in color. Most 
resins, however, in alcoholic solution give color reactions with 
ferric chloride or hydrochloric acid. 

To a portion of the filtrate obtained above add a few drops of 
basic lead acetate solution. The precipitate is so bulky as to 
almost solidify, due to the excessive amount of organic acids, 
gums and other extractive matter. The filtrate from the precipi- 
tate is almost colorless. 

Test another portion of the filtrate from the resins for tannin 
with a solution of gelatin. Tannin is present in varying but small 
quantities but should not be present in great excess. 

Color value : A. 0. A. C. — Tentative. Pipette 2 cc. of the ex- 
tract into a 50 cc. graduated flask and make up to the mark with 
a mixture of equal parts of 95 per cent alcohol and water. De- 
termine the color value of this diluted extract in terms of red 
and yellow by means of a Lovibond tintometer, using a one-inch 
cell. To obtain the color value of the original extract multiply 
the figures for each color by 25. 

Residual Color After Precipitation With Lead Acetate: A, 0. 

A. C. Method — Tentative. Determine the color value, in terms 
of red and yellow, of the filtrate from the lead acetate precipitate 



VanilIvA Analysis 



645 



as obtained under "Preparation of Solution," using a 1-inch Lovi- 
bond cell. Multiply the reading by 2 to reduce the results to 
the basis of the original extract. If the actual reading of the 
solution is greater than 5 red and 15 yellow, as may happen if 
the extract is highly colored with caramel, a ^ or ^ inch cell 
should be employed, and the readings multiplied, respectively, by 
4 or 8. Divide the figures for red and yellow, respectively, by the 
corresponding figures of the original extract and multiply the 
quotients by 100, to obtain the percentages of the two colors re- 
maining in the lead acetate filtrate. 




Pig-. 154. I^ovibond Tintometer. 

Courtesy Arthur H. Thomas Co. 



Calculate also the relation of the red to yellow in both ex- 
tract and lead acetate filtrate. 



GELATIN. 

Gelatin is an albuminoid-like material extracted from bones 
and other animal parts by heating them in water. When hot 
water containing as low as one per cent of gelatin cools a jelly 
forms. The substance is used legitimately in preparing a number 
of palatable dishes and as a stabilizer in ice cream. When the 
substance is added surreptitiously to produce body and apparent 
richness in dairy products, as for example, to ordinary market 
cream, it is used for a deceptive purpose and is then classed as 
an adulterant. 



646 Analysis of Dairy Products 

The quality of gelatin may vary according to the material from 
which it is made, the methods of manufacture and the presence 
or absence of impurities. The pure food regulations of the United 
States Department of Agriculture specify that there shall be, per 
million parts of gelatin, not more than 350 parts of sulphurous 
acid, 100 parts of zinc, 300 parts of copper and 1,25 parts of ar- 
senic. 

Grading and Testing- Gelatin: Place .30 grams of the granu- 
lated gelatin in a 250 cc. container and add 180 cc. of cold water, 
stir thoroughly and soak for 1 hour. Then place the vessel con- 
taining the soaked gelatin in a water bath at 60° C. (140° F.) 
until the gelatin is all dissolved. Let stand about ten minutes 
longer, then determine the color and odor. 

Mojonnier Viscosity Test for Gelatin. T. Mojonnier. Add to- 
gether dry gelatin and water in the exact proportions to make 200 
cc. of solution containing .10, .25, .50, .60, .75, 1.00, and 1.50 per 
cent respectively, of the gelatin. Heat to 140° F. until the gela- 
tin is all dissolved. Cool and hold in ice water for at least twelve 
hours. Determine the viscosity in each sample using the Mo- 
jonnier-Doolittle viscosimeter, described in this chapter. Read 
and record results in terras of degrees of retardation. For 
comparison make determinations using water only. 

The best qualities of gelatin when made up into solutions con- 
taining one per cent or more of the gelatin, may yield a product 
that is too viscous to permit of the determination of the viscosity 
by the above method. 

Frohring Gelatin Foam or Air Test. W. 0. Frohring. Add to- 
gether dry gelatin and water in the exact proportion required to 
make 100 cc. of solutions containing various percentages of gela- 
tin. The most practical amounts are .20, .50, .60, .70, .80, .90, and 
1.00 per cents respectively, of the gelatin. Heat to 140° F. until 
the gelatin is all dissolved. Cool and hold in ice water for at least 
twelve hours. Whip for one minute using electric soda fountain 
mixer. Read and record increase in volume, immediately after 
whipping and at end of half hour interval. 

Jelly Value of Gelatin: A method that is practical and easily 
applied in determining the jelly value of gelatin has been de- 
veloped by Clark and Dubois."^ They make up from each sample 



Grlatin Tests 647 

a series of gelatin solutions of known concentrations. These are 
allowed to cool and set, and are then heated to a predetermined 
temperature. The concentrations that go into solution are then 
noted. The sample having the lowest percentage concentration 
that does not go into solution has the highest jelly value. 

Procedure : Number from 1 to 10 a series of 6-inch test tubes 
that are nearly equal in diameter, graduated at the 10 cc. mark 
and fitted with corks. Into tube No. 1 weigh 0.1 gram of the 
granulated gelatin, into tube No. 2 weigh 0.2 gram and so on, 
increasing the amount of gelatin in each successive tube by 0.1 
gram. Add cool water until the tubes are full to the 10 ce. mark, 
place a glass rod in each tube and stir the contents occasionally 
during several hours, then stand the tubes in boiling water until 
the gelatin is completely dissolved. When complete solution is 
obtained remove the glass rods and cork the tubes tightly to pre- 
vent the formation of a skin on the surface when the gelatin 
cools. Cool the tubes considerably below 10^ C. (50° F.) if that 
is to be the observation temperature. Next place the tubes in 
water and warm it up very gradually to the temperature at which 
the observation is to be made (10 C. is advised for making the 
observation). Observation of the "set" is then made by tilting 
the tubes and noting which contain the gelatin in solution and 
\vhich do not. 

The observation may be made at other temperatures, but 10° C. 
is considered as a good average working temperature. After ex- 
perience has been obtained by working with the method it may 
be found that it is not necessarj* to make up a series of as many as 
10 tubes in order to cover the concentrations that go into solution 
or remain set at the observation temperature. 

GUM ARABIC. 

McMillan's Method for Analyzing Gum Arabic.'- Reagent: 
Dissolve 50 grams, of copper acetate in water, add an excess of 
ammonia and make the solution up to 1000 cc, using alcohol and 
water in such proportion that the tinal solution contains 50 per 
cent of alcohol. 

Determination: Place 50 ee. of a 5 per cent solution of the 
original sample in a beaker, add an equal volume of alcohol and 



648 Analysis of Dairy Products 

25 cc, of the copper reagent, stirring constantly. Filter through 
a weighed paper. Wash the precipitate with 50 per cent alcohol 
containing ammonia, then with 70 per cent and finally 95 per 
cent alcohol. Dry to constant weight at 105° C, ignite and weigh 
the ash. 

Moisture: Determine the percentage of moisture in some of 
the original sample by driving in a current of hydrogen at 105° C. 

Add the weight of the moisture to the weight of the ash and 
subtract the sum thus obtained from the weight of the substance 
obtained by precipitation with the copper reagent. The differ- 
ence is the "net gum arable." 

GUM TRAGACANTH. 

At present methods have not been completed which satisfac- 
torily determine the relative merits of different samples of gum 
tragacanth, or, for readily distinguishing the presence of all 
adulterants and substitutes. The most common adulterant and 
substitute is Indian gum, but Peru gum, and nourtoak root mixed 
with gypsum have also been used. The adulterant may be less 
soluble than gum tragacanth, or after bringing it into solution 
with difficulty, it may liquefy so far that it is of little value. 
The A. 0. A. C. gives the following method for measuring the 
purity of gum tragacanth. 

Volatile Acidity (Tentative). — The quantity of volatile 
(acetic) acidity developed in the acid hydrolysis of gum traga- 
canth (Astragalus gummifer) affords a valuable index of the 
purity of this commodity when compared with results obtained 
by similar treatment of so-called "Indian gum" (Cochlospernum 
gossypium and Sterculia urens). The term "volatile acidity" 
expresses the number of cc. of N/10 potassium or sodium hy- 
droxid required to neutralize the volatile (acetic) acid obtained 
by distilling with steam the products of the action of boiling 
aqueous phosphoric acid on 1 gram of the gum. 

Treat 1 gram of the whole or powdered sample in a 700 cc. 
round-bottomed, long-necked flask for several hours in the cold 
with 100 cc. of water and 5 cc. of sirupy phosphoric acid until the 
gum is completely swollen. Boil gently for 2 hours under a 



Specific Heat 649 

reflux condenser. A very small amount of cellulose substance 
Avill remain undissolved. Now distill the hydrolyzed product 
Avith steam, using a spray trap- to connect the distillation flask 
with the condenser and continue until the distillate amounts to 
600 cc. and the acid residue to about 20 cc. Do not concentrate 
too far, as this would scorch the non-volatile, organic decomposi- 
tion products and possibly contaminate the distillate. Titrate the 
distillate with N/10 potassium hydroxid, using 10 drops of 
phenolphthalein as an indicator, finally boiling the liquid under 
examination until a faint pink color remains. Correct the result 
by a blank determination and express the final results in terms 
of the number of cc. of N/10 alkali required, as in the above 
definition. 

While tragacanth yields a practically colorless solution when 
boiled with aqueous phosphoric acid, Indian Gum, on the other 
hand, gives a pink or rose solution. This reaction may be used 
as a preliminary test for the detection of Indian gum. 

THE SPECIFIC HEAT OF DAIRY PRODUCTS. 

In recent years processes for heating and refrigerating have 
become important economical factors in the manufacture and 
preservation of dairy products. The production of high or low 
temperatures in large masses of material involves considerable 
expense and, unless the methods employed in obtaining them are 
properly controlled, when applied to the products of the dairy 
there is always present the danger of further loss through 
damaging the materials. Different substances vary in the amount 
of heat required to raise their temperature through a given range. 
The causes of these differences are both physical and chemical, 
and the capacity of a substance to absorb heat may vary con- 
siderably as changes occur in its physical and chemical status. 

The unit of heat measurement or thermal unit is the calorie. 
It is the amount of heat required to raise the temperature of one 
gram of water one degree centigrade. As the amount varies 
slightly with changes in temperature, the temperature at which 
measurements are made should always be given. It should be 
stated that the large calorie is used in engineering practice. It 
is the amount of heat required to raise one kilogram of water one 



650 Analysis of Dairy Products 

degree C. The British thermal unit (B. T. U.) is the heat required 
to raise one pound of water one degree Fahrenheit, while in most 
European continental countries the kilogram is substituted for 
the pound, as the unit of weight. 

When substances having different temperatures are brought 
together the temperature of the warmer material falls on account 
of a transference of heat to the colder material. The amount of 
heat that is transferred in this way by unit mass of a substance 
while cooling 1° C. is called the specific heat of that substance. 
As this amount is equal to the number of calories required to 
raise unit mass of the substance 1'^ C, the specific heat of a sub- 
stance may be defined as the number of calories required to raise 
the temperature of 1 gram of the substance 1° C. 

Methods for studying the specific heat of different substances 
have been in process of development during the past century. Re- 
cently Hammer and Johnson^'' designed special apparatus and 
made a study of the specific heat of several dairy products. A 
description of one of the forms of apparatus developed, their 
method for making specific heat determinations, and some of the 
results obtained follow. 

Apparatus Design. — "In apparatus No. 1, for variable voltage. 
Fig. 155, the outer insulating walls (1) of the apparatus consists 
of pressed cork, such as is used in the construction of refriger- 
ators and thermostats. In the cylindrical cavity (2), which may 
be gouged out with a sharp paring knife, is the copper (or glass) 
calorimeter vessel (3) (Dia.:=6.25 cm. Height=8.75 cm.) for 
holding 100 gms. of sample; (4) is another copper vessel (D= 
4.7 cm., H==8.1 cm.) with a capacity of 100 gms. of water, in 
which is immersed an electric light bulb and a thermometer to 
which a stirrer is attached. The vessel is arranged with a tight 
fitting cap having a bayonet catch. Leads from the electric lamp 
pass up through a fibre or glass tube (5) which also serves as a 
handle for the whole vessel and its contents which we may call 
the "heater." The upper portion (6) of the cork insulating vessel 
has cut through it a cylindrical hole just a trifle greater in 
diameter and deeper than the heater. Between the upper and 
lower portions of the cork container is a heavy asbestos board 
partition (7) the middle third of which is a slide that may be 
readily inserted or withdrawn. 



Specific Hk at 



651 



Operation of the Apparatus.— The operation of the apparatus 
is as follows: . 100 grains of milk is weighed in the vessel (3) 
which is placed in the cork thermostat. A thermometer (8) 
reading .1 degree C. is then inserted. The electric current is 
turned on the heater (4) and this is allowed to come to a suitable 
temperature outside of the thermostat. If the temperature of 
the milk is 20 degrees C. it will be sufficient to heat the heater to 
about 45° C. It is then placed in the cavity (9) and allowed to 
come to a condition such that radiation takes place regularly, the 
thermometer (8) is read, and when the mercury of the thermo- 
meter (10) comes to a chosen mark the heater is dropped down 




Pig. 155. 
Specific Heat Determination Apparatus. 



into the liquid in the calorimeter vessel. The liquids of both ves- 
sels are agitated regularly until the thermometer (8) shows the 
maximum rise of temperature. Results are gotten for water and 
the substance in hand for the same range of temperature. The 
specific heat of the substance is inversely proportional to the 
temperature rise, the rise being compared with that of water 



652 Analysis of Dairy Products 

under like conditions. Corrections for radiation and the water 
equivalent of the calorimeter must of course be applied. 

Specific Heat of Whole Milk. The samples of milk used in the 
tests were from the composite milk delivered at the College 
creamery. The fat content varied from 3.4 per cent to 4.9 per 
cent, most samples having about 4.3 per cent. About 15 hours 
elapsed between the time the milk was drawn from the cows 
and the time of the tests. After the milk was delivered at the 
creamery the samples were kept in the refrigerator. 

The averaged results for the various temperatures have been 
plotted in the form of a curve. See Fig. 156, 

Though the changes in the specific heat of milk between 
15,0° C, and 60.0° C. are not great, still there is shown by our 
data a fairly pronounced maximum at about 30.0° C, 

Specific Heat of Skim-milk. Samples of sweet, skim-milk 
varying in fat content from 0.30 to 0.38% were obtained from a 
small separator immediately after running through the machine. 
The average 15 determinations on 4 different samples made 
beween approximately 20 and 40° C. gave an average value of 
0.949 Over the pasteurizing range of 60°-70° C. the average 
value of 0.963 was obtained. 

Specific Heats of Cream. The creams used were sweet and 
were separated from composite milk in the morning and kept in 
a refrigerator until evening when the measurements were carried 
out. A series of determinations were made on each sample over 
quite a wide range and generally up to aout 60° C. 

In the course of the measurements on creams it was found 
that apparent specific heats considerably above 1,000 were often 
encountered. This peculiarity of cream was also noted by Fleish- 
mann. The authors' data for 33.5 per cent, 30 per cent, 27 per 
cent, 15 per cent'and 60 per cent creams have been obtained under 
very definite conditions and the results averaged; from the aver- 
ages the curves shown in Fig. 156 have been plotted and these 
will be discussed later. The 60% cream was first heated, as it 
v/as very viscous at room temperature. 



Specific Heat 



653 



TABLE 109. 
Specific Heat of Skim-Milk. 



SAMPLE No. 1 


SAMPLE No. 2 


SAMPLE No. 3 


Temp. C. 


Sp. H. 


Temp. C. 


Sp. H. 


Temp. C. 


Sp. H. 


18.80° 




15.35° 




21.00° 






0.951 




0.941 




0.942 


24.00° 




20.72° 




26.20° 






0.948 




0.941 




0.940 


29.70° 




25.88° 




31.20° 






0.957 




0.937 




0.948 


34.54° 




30.90° 




36.00° 






0.955 




0.958 






39.32° 




35.70° 










0.957 










43.95° 












Av. 


0.954 




0.944 




0.943 




SAMPLE No. 4 


SAMPLE No. 5 


SAMPLE No. 6 


Temp.;C. 


Sp. H. 


Temp. C. 


Sp. H. 


Temp. C. 


Sp. H. 


20.30° 




61.90° 




58.55° 






0.946 




0.977 




0.942 


25.80° 




65.68° 




62.55° 






0.960 




0.974 




0.948 


31.09° 




68.20° 




65.20° 






0.957 




0.972 




0.952 


36.14° 




70.60° 




68.10° 














0.966 










70.66° 




Av. 


0.954 




0.974 




0.952 



654 



Analysis of Dairy Products 



Specific Heat of Whey. The whey used was from composite 
milk and was obtained from the cheese vat. There was present 
from 0.25 to 0.30 per cent fat and the samples were opalescent. 
The values obtained for two samples taken at different times 
were very near one another. The average specific heat between 
23^^ and 33° C. was 0.975. 




Pig". 156. Speciffc Heat of Several Dairy Products at Various Temperatures. 



TABLE 110. 
Specific Heat of Whey. 



SAMPLE NO. L 


SAMPLE NO. 2. 


Temp. Range C 


Sp. H. 


Temp. Range C. 


Sp. H. 


22.99 
28.38 
33.60 
Average 


0.977 
0.974 
0.975 


22.93 
28.32 
33.55 
Average 


0.977 
0.975 
0.975 



Spf.cific Heat 



655 



Specific Heat of Butter. Three samples of butter taken from 
the churning on three different occasions, and containing the 
ordinary amounts of curd, salt, water and fat gave the following 
results : • . t i 4' 



TABLE 111. 
Specific Heat of Butter. 



No. 


% 
Salt 


% 

Curd 


% 

Water 


% 

Fat 


Av.-Sp. 

Heat 
30-60° C. 


I 


2.2 


0.60 


14.20 


83.0 


0.688 


II 


1.02 


0.48 


13.. 50 


85.0 


0,557 


Ill 


1.14 


0.76 


13.60 


84.5 


0.574 



The values for ordinary butter are considerably higher than 
for pure fat. This is in part due to the presence of considerable 
quantities of water. 

Specific Heat of Butter Fat. Butter fat carefully prepared 
in accordance with the specifications of the official method gave 
the following results : 

No. 1 Average from 30-60^^ C. equals 0.532 
No. 2 Average from 30°-60= C. equals 0.510 



Average 0.521 

Samples of practically pure butter fat were also prepared by 
taking freshly churned butter, placing it in a large separatory 
funnel, and keeping it in a thermostat at 43° C. so as to alloAV the 
fat, curd and water to separate by gravity. Water was added 
several times, shaken with the melted fat and allowed to separate 
and then drawn off. Next fused calcium chloride was added and 
the melted fat thoroughly dried, then filtered. The average 
value between 30° C. and 60° C. for four samples thus treated 
was 0.507. At 30° C. it was 0.485 and at 60° C. 0.530." 

'ihe results obtained by Hammer and Johnson on milk agree 
fairly well with the results obtained by previous investigators, 
but they point out that, heretofore, results obtained on cream and 



656 



Analysis of Dairy Products 



butter varied widely due to making no allowance for influencing 
factors such as the temperature range over which the substances 
were to be heated or cooled. A more detailed discussion of 
results may be found in the original publication. 

TABLE 112. 
Specific Heat Values for Milk and Milk Derivatives. 





Conditions 




Specific 
















Material 


Temperature 
C. 


% 
Fat 


Heat 


Investigator 


Reference 


Whole Milk 


16—17° 




.9406 


Chanoz & 


Grimmer-Chemie and Physiologic 








.0523 


Vaillant 


der Milch. Grig. Journ. de 
Phys. et de Pathol Generale 8, 
p. 413. 


Whole Milk 


14—16" 


3.17 


.9457 


Fleischmann 


Jour. Landwirtschaft 50, p. 33. 


Whole Milk 


27.5 up to 40 












and return 




.9351 


Fleischmann 


Jour. Landwirtschaft 50, p. 33. 


Whole Milk 






.94 


Fjord 


McKay & Larsen, Principles and 
Practices of Butter Making. 


Skim-Milk 


14—16° 


.20 


.9388 


Fleischmann 


See above. 


Skim-Milk 


27.5 up to 40 












and return 




. 9455 


Fleischmann 


See above. 


Cream 


14—16° 


19.18 


. 9833 


Fleischmann 


See above. 


Cream 


27.5 up to 40 












and return 




. 8443 


Fleischmann 


See above. 


Cream 






.7 


Fjord 


McKay & Larsen. See above. 


Butter 






.4 


Fjord 


McKay & Larsen. See above. 


Butter 


31.15 




. 5207 


Fleischmann 


See above. 


Butter 






.55 


King 


Siebel's Compcnd. Mech. Ref. & 
Eng. 



THE FREEZING POINT OF MILK. 

As the freezing point of milk is one of its least variable 
factors, it has been used with considerable success in determining 
the presence of added water. The followng temperatures of the 
freezing point of milk are given by different investigators. 

Richmond^**, about 0.55° C. (31° F.) ; BartheP^ between 0.55° 
and 0.57° C. ; Atkis''", 0.55 and further states that it never 
varies more than 0.08° C. ; Stocking''", 0.55° C. ; Griramer^^, gives 
0.54 to 0.57° C; Heinemair^ 0.54 to 0.57 and further states that 



1 



Freezing Points 



657 



dilutions with water below 10 per cent cannot be detected with 
certainty by freezing point determinations. Others state that as 
little as 5% of added water can be detected with certainty, and 
the Chem. Bulletin*", volume 7, No. 4, University of Minnesota 
Section, states that the method is reliable to a minimum of 3 
per cent of added water and gives the results shown in Table 113. 



TABLE 113. 
Detection of Water Added to Milk by Freezing Point Method. 



No. of 
Sample 


Specific 
Gravity 
at 60° F. 


Fat 


Tota 
Solids 


Solids 
Not Fat 


Freezing 
Point — 
Deg. C. 


Added 
Water 
Found 


Water 
Added 






% 


% 


% 




% 


% 


1 


1.029 


4.6 


12.92 


8.32 


0.475 


13.6 


12.0 


2 


1.0312 


4.8 


13. 7 


8.9 


0.490 


10.9 


10.0 


3 


1.0339 


5.2 


14.85 


9.65 


0.544 


none 


none 


4 


1.0346 


52 


15.03 


9.83 


0.549 


none 


none 


5 


1.0319 


5.0 


14.12 


9.12 


0.518 


5.8 


4.0 


6 


1.0314 


4.8 


13.75 


8.95 


0.505 


82. 


8.0 


7 


1.0311 


3.7 


12.35 


8.65 


0.518 


5.8 


market 


8 


1.0328 


3.7 


12.77 


9.07 


0.524 


4.7 


/market 
\sample 


9 


1.0339 


3.7 


13.03 


9.33 


0.541 


none 


fmarket 
Isample 



Different forms of apparatus have been devised for the pur- 
pose of determining freezing points. The best known are Beck- 
mann's freezing point apparatus and Hortvet's Cryoscope illus- 
trated under Fig. 157. By means of the latter apparatus the 
freezing point determination of milk may be made in less than 
10 minutes. The directions for making determination are given 
as follows: 

Insert a small caliber thistle-tube or funnel tube into the 
vertical portion of the T-tube at one side of the apparatus and 
pour in about 400 cc. of ether previously cooled to 15° C. or 
lower. Close the vertical tube by means of a small cork and 



658 



Analysis of Dairy Products 




connect the pressure bulb or pump to the air inlet tube of the 
air drying attachment on the opposite side of the apparatus. 

Measure into the inner test tube 30 to 
35 cc. of boiled distilled water, previously 
cooled to 10° C. or lower. Enough water 
should be measured in to fairly submerge 
the thermometer bulb. Insert the ther- 
mometer, which together with the stirring 
device is mounted in a sound stopper, and 
lower the test tube into the larger tube, 
which is tightly fitted into the apparatus. A 
small quantity of alcohol, sufficient to fill 
the space between the two test tubes, will 
serve to complete the conducting medium 
between the interior of the apparatus and 
tlie liquid to be tested. A sufficiently tight 
connection between the inner and outer 
tubes is afforded by means of a narrow 
section of thin walled tubing. The ther- 
mometer and stirring device should fit accurately in the stopper 
and the entire arrangement should be in a vertical position. 

By means of the pressure pump maintain a steady current of 
air through the apparatus, thereby vaporizing the ether at a 
fairly rapid rate. Arrangement may be made so as to conduct 
the ether vapors away from the operator and the apparatus 
should not be used in the vicinity of a flame. Keep the stirring 
device in a steady up-and-down motion at a rate of approximately 
one stroke each two or three seconds, or even at a slower rate 
providing the cooling proceeds satisfactorily. Maintain passage 
of air through the apparatus until the temperature of the ether 
cooling bath approaches 3° below zero, as indicated on the control 
thermometer, or until the top of the mercury thread in the special 
freezing point thermometer recedes to a point in the neighborhood 
of the probable freezing point of water. Continue the manipula- 



Pig-. 157. 
Hortvet Cryoscope. 



Freezing Points 659 

tion of the stirring device until a supercooling of sample from 
1,2 to 1.3° is observed. Also note the temperature recorded on 
the control thermometer in order to guard against excessive 
supercooling and a consequent too low convergence temperature. 
As a rule, by this time the liquid will begin to freeze, as may be 
noted by the rapid rise of the mercury thread. Manipulate the 
stirring device slowly and carefully two or three times while the 
mercury column approaches its highest point. By means of a 
suitable light weight mallet tap the upper end of the thermometer 
cautiously several times in order to insure a permanent position 
of the top of the mercury column. Observe the exact reading on 
the thermometer scale and estimate to 0.001° C. After a few 
minutes' time the mercury may begin to recede owing to the 
cooling effect of the ether in the interior of the apparatus. When 
the above observation has been satisfactorily completed make a 
couple of duplicate determinations, then remove the thermometei 
and stirring device and empty the water from the inner tube. 

Rinse out the test tube with about 20 cc. of the sample of milk 
to be tested, measure into the tube about 35 cc. of the milk, or 
enough to fairly submerge the thermometer bulb, and insert the 
tube into the apparatus. In the meantime by lowering a narrow 
tube into the ether bath, then closing the top end by means of 
the forefinger and raising to a suitable height, a judgment may be 
obtained as to whether an additional supply of ether is necessary 
for the next determination. Usually an additional 50 to 75 cc. 
of cold ether should be poured in at this stage. When the 
apparatus has once cooled down to low temperature an additional 
50 cc. of ether is sufficient on an average for every four or five 
succeeding determinations. 

Make the determination on the sample of milk, following the 
same procedure as that employed in determining the freezing 
point of water. As a rule, however, it is necessary to start the 
freezing action in the sample of milk by dropping in a small 



660 Analysis of Dairy Products 

fragment of ice (approximately 0.05 gram) at the time when the 
mercury column has receded to a place from 1.2 to 1.3° below 
the probable freezing point. A rapid rise of the mercury column 
results almost immediately. Manipulate the stirring device slowly 
and carefully two or three times while the mercury column ap- 
proaches its highest point. Complete the adjustment of the 
mercury column in the same manner as in the preceding deter- 
mination, then observe the exact reading on the thermometer scale 
and estimate to 0.0001°. The algebraic difference between the 
reading obtained on the sample of water and the reading obtained 
on the sample of milk represents the freezing point of the milk. 

For deducing the proportion of added water from the deter- 
mined freezing point use Winter's Table as published in extended 
form in the Chemical News, Vol. 110, 1714, pages 283-284, or use 
the porcelain scale accompanying the cryoscope. The percentage 
of added water (W) may also be calculated as follows: 

100 (T— T^) 
W== ^^ 

in which T represents the average freezing point of normal milk 
( — 0.550) and T^ the observed freezing point on a given sample. 

THE PREPARATION OF PURE MILK CONSTITUENTS. 

Milk Fat: — Place in a tall cylinder fresh unsalted butter ob- 
tained by churning pure sweet cream, hold at a temperature of 
60° C. (140° F.) until the water and curd settles. Filter most 
of the melted fat without allowing any of the water to get onto 
the filter. Dry the filtered fat carefully and preserve in air tight 
glass stoppered jars in a cool place away from the light. 

Pure Casein. Van Slyke and Baker Method". — The aim of 

this method is to introduce an acid into the milk in a manner 
that approaches that of natural souring, and then to separate the 
casein from the serum while all of the calcium and inorganic 
phosphorous are in solution. 



Separating Milk Constituents 661 

Description of Apparatus.— The apparatus used in coagulating 

casein in milk by adding acid under the surface with rapid 

stirring consists of four main parts : the milk 

container, the burette, the acid-carrying 

tube, and the stirrer (see Fig. 158). 

(1). Milk container: — A wide mouthed, 
broad, low form container (A) of the de- 
sired capacity permits the best stirring with 
least vibration. 

(2). Burette: — Use a burette with two 
stop cocks, one for regulating the flow of 
acid and another to serve as a shut-off. 

(3). Acid tube :— Diameter of bore 1.5 
to 2 mm., the tip of the tube is bent upward, 
with opening (T) in the form of a narrow 
slit. A rubber joint connects the tube to 
the burette. A pinch-cock must not be used 
on the rubber connection in place of the 
second stop cock or milk and casein may be 
drawn into, and clog the tip opening. 

(4). Stirring-rod (D) :— This is made of 
rigid glass tubing about 1 cm. in diameter 
mounted on ball bearings. It must revolve 
rapidly at a speed sufficient to stir the milk 
thoroughly and without excessive foam. The 
connection with the motor (M) is made by 

means of rubber tubing (R). A rlieostat connection controls the 

speed of the stirrer. 

Placing the stirrer at one side of the container prevents the 
formation of a whirlpool and drawing air into the milk which 
would cause foaming. The acid delivery tube is so placed 
that the whirling milk washes the tip but is not thrown against 
it, thus avoiding clogging the opening. 




rig-. 158. 

Casein Coagrulating 

Apparatus. 



662 Analysis of Dairy Products 

Milk Used. — One liter of fresh vmdiluted skim-milk from a 
centrifugal separator is used. 

Acids Used. — Normal lactic acid or a mixture of 1 part normal 
hydrochloric acid and 1 or 2 parts of normal acetic acid is 
preferred. 

Addition of Acid and Coagulation of Casein. — With the stirrer 
revolving at 2000 to 3000 revolutions per minute, the acid is 
allowed to flow so slowly into the milk that no sediment is found 
at the bottom of a sedimentation tube after centrifuging a few 
cc. of the milk. About 45 cc. of the acid may usually be added 
in 30 minutes. When 60 cc. has been added the rate is decreased 
until the coagulation point is nearly reached, as shown by the 
following tests : 

Titrate a sample of the original milk to the coagulating point, 
then calculate and add the right amount of acid slowly, with 
constant stirring as described above, after the milk in the 
apparatus has stood about 3 hours, with stirrer revolving at about 
500 revolutions, or less, per minute. Brom-cresol purple may also 
be applied as an indicator. 

As the casein precipitation approaches, foaming may be con- 
trolled either by adding a few drops of octyl alcohol, or by using 
a stirrer free from vibration, or by using a container large 
enough to accommodate the foam. 

When a portion of the mixture on centrifuging in a sediment 
tube yields a definite supernatant layer of solution the addition 
of acid is stopped. About 90 cc. of the normal lactic acid or of 
a mixture of 1 part of normal hydrochloric acid and 2 parts of 
normal acetic acid is ordinarily required. About 75 cc. of normal 
hydrochloric acid usually is sufficient. The mixture is then 
allowed to stand 2 to 4 hours with gentle stirring. 

Treatment of Casein Coagulum. — The casein is centrifuged in 
two or four containers at 1000 revolutions per minute, the super- 



Separating Milk Constituents 663 

natant liquid decanted, and the casein washed with distilled 
water 4 or 5 times, centrifuging between the washings and break- 
ing up the coaglum to a smooth paste with a rubber tipped glass 
rod. Wash with 95 per cent alcohol twice and with ether three 
times, adding the liquids gradually with vigorous beating. The 
alcohol removes alcohol soluble material and water. The water 
would cause the casein to cake on drying. The ether removes 
any fat present. 

Spread the washed casein on a smooth, fiat surface to dry 
and work the mass gently with a spatula while drying in order 
to obtain a finely divided product. 

Control of Ash and Phosphorus Content. — A product low in 
phosphorus, about 0.80 '/( , results from holding the casein in an 
uncoagulated condition for about 3 hours at a degree of acidity 
just below the coagulation point. A casein with low ash, 0.05 to 
0.15 per cent, is obtained by holding the casein after coagulation 
in the slightly acid solution for 2 to 4 hours. The acid combines 
with the calcium after decomposing the calcium caseinate, thus 
jnelding a casein of low ash content. It does not appear possible 
to remove completely the inorganic prosphorus that remains 
after coagulation once occurs as shown in the table that follows. 

Albumin. — Add sufficient acid to skim-milk to make the solu- 
tion 0.1 per cent acid. The acid must be added very slowly with 
vigorous constant stirring. Warm the milk, if necessary to cause 
casein precipitation, to about 40° C. Stir until the liquid is 
clear, filter through cheese cloth. Refilter the portion that comes 
through first until a filtrate is obtained that is perfectly clear and 
free of casein. Boil the filtrate for about 15 minutes. Filter 
through cheese cloth, wash the precipitate several successive 
times with distilled water, squeezing out as much of the water 
as possible after each washing. Rub the albumin in a mortar 
with 80 per cent alcohol, pour off the alcohol and press out as 
much as possible, and repeat the treatment several times. Finally 



664 



Analysis of Dairy Products 



extract with ether 2 or 3 times and dry at as Ioav a temperature as 
possible. 

TABLE 114. 



Time of Standing 
Before Coagulation 


Time of Standing 
After Coagulation 


Ash 


Phosphorus 


Hours 


Hours 


Per Cent 


Per Cent 





6 


0.15 


0.85 





24 


0.14 


0.86 





24 


0.15 


0.83 


3 





0.46 


0.81 


4 





0.43 


0.81 


1 


12 


0.15 


0.85 


3 


15 


0.05 


0.80 


3 


18 


0.11 


0.81 


4 


4 


0.10 


0.81 


16 


4 


0.10 


0.81 


30 


10 


0.10 


0.80 



Milk Sugar. — Use the filtrate from the albumin. Make it 
slightly alkaline with lime water and add 5 grams (more if 
necessary) of alum solution for each original 100 pounds of milk. 
Evaporate to one-sixth of original bulk. Add an equal volume 
of wood alcohol and let stand. Filter otf the sugar crystals, 
redissolve in distilled water and filter over animal charcoal. 
Evaporate and if necessary dissolve again and repeat the purifica- 
tion process. Dry thoroughly to prevent mold growth and keep 
in glass stoppered bottles. 

Ash. — Evaporate skim-milk to dryness in a large evaporator 
over a free flame. Incinerate the residue to whiteness in a muffle 
using porcelain dishes or crucibles for the purpose. 

Citric acid. (Method of T. Mojonnier). — Remove the granules 
of calcium citrate from the bottom of evaporated milk cans. 
Wash thoroughly with water. Dry. Grind to a fine powder. 
Add 5 per cent sulphuric acid in quantity slightly under that 
required to combine with all the calcium contained in the above 
salt. The reaction takes place according to the following 
equation : — 

Ca3(C6H30,),+4H,0+3H,S04=3CaSO,+2C6HsO,+3H.,0 
570.144 : 294.228=1.0 : .5161 



Hydrogen Ion Concentration • 665 

Therefore add the sulphuric acid in the proportion of one part 
calcium citrate to .5161 part sulphuric acid calculated upon the 
water free basis. 

Heat the mixture carefully, not to exceed 140° F. 

Filter hot through bone black. Evaporate to small bulk, and 
allow to stand in evaporating dish until the citric acid crystals 
have separated. Separate the crystals from the motor liquor. 
Recrystalize until pure white crystals are obtained. 

HYDROGEN ION CONCENTRATION AND ITS DETERMINATION. 

The theory of electrolytic dissociation announced by 
Arrhenius"*' in 1887 has been the subject of study and investiga- 
tion for several years. While, at present, there is not a clear 
conception of all of the phenomena connected with it, the results 
already obtained may be applied to advantage especially in the 
different branches of chemistry and biology. In those fields 
many workers apply it daily and a reasonable understanding of 
the theory of electrolytic dissociation, and ability to apply it, 
by workers in bacteriology and certain branches of dairying is 
already, or rapidly becoming, a necessity. For example, in mak- 
ing culture media the amount of dissociated hydrogen must be 
controlled on account of its influence on the growth of bacteria. 
In the dairy industry, in addition to its application in dairy 
bacteriology, a knowledge of the amount of dissociated hydrogen 
present in milk may be used to advantage in milk inspection work 
and in selecting and allotting milk to be manufactured into 
different dairy products. In the food processing industry it is 
known that the temperature necessary to employ and the duration 
of its application to a given food substance, in order to obtain 
sterilization, is affected by the nature, condition and especially, 
in a large measure, by the acidity of the substance. The acidity 
was formerly measured by its degree of concentration, but at 
present it is known that a part of some of the acid elements may 
be present in acid solution in a condition which enables them to 
act more intensely than the remainder of the acid. An acid 
contains hydrogen, and when in solution has the property of 
dissociating into two components, namely hydrogen ions and a 
reserve quantity of acid capable of producing them. The hydro- 
gen ions act more intensely than the remainder of the acid and 



(^ Analysis of Dairy Products 

in the processing of food play an important part in the destruction 
of bacteria. Therefore, a means of measuring the acidity due to 
dissociated hydrogen in food liquids may be used to great 
advantage in the food processing industry. 

The relative amounts of dissociated hydrogen present in acid 
solutions are expressed by the terms "hydrogen ion concentra- 
tion" or "pH" value. In order to bring out clearly the meaning 
of these terms Bigelow and Cathcart 's*'^ excellent description is 
given here. 

Explanation of pH Value and Hydrogen Ion Concentration. — 

"Water has the property of dissociating or separating into its 
components to a very slight extent as shown in the equation : 
HOH=H+ -|-0H~. The symbol H+ is that of the hydrogen ion 
and OH that of the hydroxyl ion. The + and signs signify 
that these ions carry respectively a positive and a negative charge 
of electricity. Only about one one-hundred-millionth of one per 
cent of pure water is dissociated into hydrogen ions and there are 
an equal number of hydrogen and hydroxyl ions. 

All acids contain hydrogen in combination and, dissolved in 
water, dissociate to yield hydrogen ions; whereas all alkalis con- 
tain hydrogen and oxygen in the proportion found in the 
hydroxyl ion and, dissolved in water, dissociate to yield hydroxyl 
ions. All the properties common to acids are due to the hydrogen 
ions. When we say that an acid tastes sour we mean in reality 
that the hydrogen ions present taste sour, for it is these that give 
the sensation of sourness. When we speak of an acid attacking 
the tin on tin plate, we should think of the hydrogen ions as the 
active agent. In like manner all properties common to alkalies 
are due to the hydroxyl ions. The brackish taste, the smooth 
feeling on the fingers, are properties of the hydroxyl ions. The 
hydrogen ion and the hydroxyl ion neutralize each other. There- 
fore water has neitlier acid nor alkaline properties to our usual 
senses. 

The different acids, and also the alkalies, vary in the degree of 
dissociation and therein lies the strength or weakness of an 



I 



Hydrogen Ion Concentration 667 

acid or alkali. When we find that a one per cent solution of 
hydrochloric (muriatic) acid is much more sour than an equiva- 
lent solution of acetic acid, it is because a much greater propor- 
tion of the former is dissociated to yield hydrogen ions." 

Baker and Van Slyke** explain clearly some of the fund- 
amental facts bearing on hydrogen ion concentration and its 
relation to titration methods used in determining the acidity and 
alkalinity of solutions. Extracts from their work, which follow, 
are simple enough to enable those with some knowledge of 
chemistry to understand the principles involved. 

In explaining neutrality, acidity and alkalinity in terms of ions 
of hydrogen and hydroxyl, they point out that : 

"(1). A solution is neutral when the number of free hydro- 
gen ions is the same as that of the free hydroxl ions (H+ = OH~). 

(2). A solution is acid when the number of free hydrogen ions 
is greater than that of the free hydroxyl ions (H+>OH~). 

(3). A solution is alkaline when the number of free hydrogen 
ions is less than that of the free hydroxjd ions (H+<OH~). 

It is not necessary for our purpose to describe here the method 
used in making measurement of the number of free hydrogen ions 
or hydrogen ion concentrations. It is, however, essential to con- 
sider the method of expressing quantitatively the results of such 
measurements. 

Hydrogen ion concentration can be expressed quantitatively 
in two ways: (1st) In terms of normal solution or hydrogen ion 
normal Ch, and (2nd) in the form of the symbol, pH. Each of 
these expressions has its advantages and objectionable features. 
For those who have always been accustomed to express acidity 
and alkalinity in terms of the normal solution, it is extremely 
awkward to interpret pH values in relation to the reactions of 
solutions. This is owing to the fact that the mathematical 
method of obtaining the values of pH is such that the higher the 
figure representing the value of pH, the lower is the hydrogen 
ion concentration. Thus, an increase in the value of pH indicates 
a decrease in the hydrogen ion concentration. It is, therefore, 



668 Analysis of Dairy Products 

important to understand the meaning of the value of pH more 
fully in relation to neutrality, acidity and alkalinity as com- 
monly expressed. 

In pure water, the concentration of hydrogen ions is equal 
to that of hydroxyl ions. Therefore, as a starting point, pure 
water is regarded as a really neutral solution, or, stated in 
another way, the hydrogen ion concentration of pure water is 
believed and is taken to be that of true or absolute neutrality. 
Consequently, the concentration of hydrogen or of hydroxyl ions 
in pure water is called the true or absolute neutral point. Now, 
by actual measurement, the hydrogen ion concentration of pure 
water, expressed in terms of normal solution (Ch) is known to 
be .000,000,1 N, or, expressed more conveniently in abbreviated 
form IXIO"^ N; and this value represents quantitatively the true 
or absolute neutral point. On this basis, solutions are acid when 
they contain hydrogen ion concentrations greater than, or hydro- 
xyl ion concentrations less than, 1X10~^ N; and solutions are 
alkaline when they contain hydrogen ion concentrations less than, 
or hydroxyl ion concentrations greater than, IX 10"'^. 

Further, when expressed in terms of pH, the hydrogen ion 
concentration of pure water (1X10~^ N) has a value of 7. In 
the scale of pH values, 7 is therefore the true neutral point, and 
all values greater than 7 indicate alkaline solutions, while all 
values less than 7 indicate acid solutions." 

In order to enable one to compare easily the values furnished 
by these two methods of expressing hydrogen ion concentration, 
we have prepared Table 115, giving the equivalent values of 
hydrogen ion concentration for pH values varying from 1 to 13 
and also of hydroxyl ion concentrations for pH values varying 
from 7 to 13. 

The first column in the table gives figures for pH values 
varying from 1 to 13 ; the second and third columns show the 
equivalent values of hydrogen ion concentrations expressed in 
terms of the hydrogen ion normal (Ch) or normal solution, the 
abbreviated form being given in the second column and the full 
form, expressed decimally, in the third column. In the fourth 
column the character of the reaction is stated. In case of pH 



Hydrogen Ion Concentration 669 

values higher than 7, the equivalent values are given for hydroxyl 
normal (Coh) or normal solution in columns six and seven. 

In order to bring out a simple relation existing between the 
pH values and their equivalent expressd in terms of hydrogen 
ion and hydroxyl ion normal, pH values are taken at intervals 
of 0.3 in most cases. It will then be observed that the following 
rules apply with close approximation when we take any two 
points in the range of pH values differing by 0.3 : 

(1) A decrease of 0.3 in the value of pH at any point is 
equivalent to doubling the Ch value at that point. 

(2) An increase og 0.3 in the pH value at any point is equiva- 
lent to halving the Ch value and doubling the Coh value, at that 
point. 

For example when the pH value equals 2, the equivalent Ch 
value is 0.01; when pH decreases 0.3, that is, to 1.7, Ch equals 
0.02. Again, when the value of pH equals 7.1 the Ch value is 0.8 X 
10-^ ; when pH increases 0.3, that is, becomes 7.4, the Ch value is 
0.4X10-'. At the same point (pH, 7.1), the Coh value is .125X 
10-® ; when the value of pH increases to 7.4, the equivalent Coh 
value is .250X10-®. 

It is obvious that the use of the simple numbers representing 
pH values is more convenient than the numbers representing Ch 
or Coh values. It is evident also that when one desires to plot 
hydrogen ion concentration figures upon co-ordinate paper, the 
pH values possess a marked advantage over the other form of 
expression, especially when the range of differences in values is 
large. 

Table 115 will be found useful for those who have been ac- 
customed to think, not in terms of pH values, but only in those 
of hydrogen or hydroxyl ion normal. It can be seen that the 
pH value of 1 is approximately represented, for example, by 
tenth-normal (O.IN) hydrochloric acid ; while the pH value of 13 
is represented by tenth-normal sodium hydroxide. 

Many are accustomed to express the concentration of solutions 
only in fractional form, as, for example, N/10 instead of the deci- 
mal form, .IN. For such, the relations of pH values to the various 



670 



Analysis of Dairy Products 





p< 




X 


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M 


tH 




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(3 


U 


o 


I-) 




CQ 




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-t-) 


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OO OQ 
OOO O 






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X" - - 

00 -^i (N ' 



K 






^ Tjtl^O 



« "* t^O 



^ -^ t^ o 



^-^ t^o 



Hydrogen Ion Concentration 



671 



H 



go 

la 

OS 






M o 



:2 S 



O^ 



o o o< 

o o o < 
o o O ! 
ooo< 



X^ 



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•-i (M lO O 












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T-H (M LO O 



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0000 
0000 



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0000 



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672 



Analysis of Dairy Products 



concentrations of solutions can be brought out more clearly by 
the following illustrations, using HCl and NaOH and assuming 
that they are completely ionized. 







TABLE 116. 






pH Values 


HCl 

Concentrations Expressed 


pH Values 


NaOH 
Concentrations Expressed 




Decimally 


Fractionally 


Decimally 


Fractionally 




.IN 


N 

To 


8 


.000,001 N 


N 


1.0 


1,000,000 




.04 N 


N 
25 


9 


.000,01 N 


N 


1.4 


100,000 


1.7 


.02 N 


N 
50 


10 


.0001 N 


N 
10,000 




.01 N 


N 
100 


11 


.001 N 


N 


2.0 


1,000 


2.1 


.08 N 


N 
125 


11.1 


.00125 N 


N 
800 


2.4 


.004 N 


N 
250 


11.4 


.0025 N 


N 
400 


2./ 


.002 N 


N 
500 


12.0 


.01 N 


N 
100 


b.O 


.001 N 


N 


12.1 


.0125 N 


N 


1,000 


80 


4.0 


.0001 N 


N 


12.4 


.025 N 


N 


10,000 


40 


5.0 


.000,01 N 


N 
100,000 


12.7 


.05 N 


N 
20 


6.0 


.000,001 N 


N 
1,000,000 


13.0 


.1 N 


N 
10 



In Table 117 we give the pH values and their equivalent C 
values for each 0.01 pH, ranging between 1 and 2. By the use 
of this table one can readily ascertain values intermediate be- 
tween those given in Table 116. These intermediate figures can 
be used for any part of the range of values given in Table 116 by 



Hydrogen Ion Concentration 



673 



adapting the decimal properly. By the use of Tables 116 and 117 
in combination, one can convert pH values into Ch values, or vice 
versa, simply by inspection and without calculation. 

TABLE 117. 
Inteimediate pH and Cjj Equivalents for Use with Table 116. 



pH 

Values 


C 

Values 


pH 

Values 


C 

Values 


pH 

Values 


c 

Values 


pH 

Values 


C 

Values 


pH 

Values 


C 

Values 


1.00 


.1000 


1.20 


.0632 


1.40 


.0400 


1.60 


.0251 


1.80 


.0159 


1.01 


.0980 


1.21 


.0619 


1.41 


.0392 


1.61 


.0246 


1.81 


.0156 


1.02 


.0959 


1.22 


.0606 


1.42 


.0384 


1.62 


.0241 


1.82 


.0152 


1.03 


.0939 


1.23 


.0592 


1.43 


.0375 


1.63 


.0236 


1.83 


.0149 


1.04 


.0918 


1.24 


.0579 


1.44 


.0367 


1.64 


.0231 


1.84 


.0146 


1.05 


.0898 


1.25 


.0566 


1.45 


.0359 


1,65 


.0226 


1.85 


.0143 


1.06 


.0877 


1.26 


.0553 


1.46 


.0351 


1.66 


.0220 


1.86 


.0139 


1.07 


.0856 


1.27 


.0540 


1.47 


.0343 


1.67 


.0215 


1.87 


.0136 


1.08 


.0836 


1.28 


.0526 


1.48 


.0334 


1.68 


.0210 


1.88 


.0133 


1.09 


.0815 


1.29 


.0513 


1.49 


.0326 


1.69 


.0205 


1.89 


.0129 


1.10 


.0795 


1.30 


.0500 


1.50 


.0318 


1.70 


.0200 


1.90 


.0126 


1.11 


.0779 


1.31 


.0490 


1.51 


.0311 


1.71 


.0196 


1.91 


.0123 


1.12 


.0762 


1.32 


.0480 


1.52 


.0305 


1.72 


.0192 


1.92 


.0121 


1.13 


.0746 


1.33 


.0470 


1.53 


.0298 


1.73 


.0188 


1.93 


.0118 


1.14 


.0730 


1.34 


.0460 


1.54 


.0291 


1.74 


.0184 


1.94 


.0116 


1.15 


.0714 


1.35 


.0450 


1.55 


.0285 


1.75 


.0180 


1.95 


.0113 


1.16 


.0697 


1.36 


.0440 


1.56 


.0278 


1.76 


.0175 


1.96 


.0110 


1.17 


.0680 


1.37 


.0430 


1.57 


.0271 


1.77 


.0171 


1.97 


.0108 


1.18 


.0665 


1.38 


.0420 


1.58 


.0264 


1.78 


.0167 


1.98 


.0105 


1.19 


.0648 


1.39 


.0410 


1.59 


.0258 


1.79 


.0163 


1.99 


.0103 


1.20 


.0632 


1.40 


.0400 


1.60 


.0251 


1.80 


.0159 


2.00 


.0100 



There are two points in connection with the determination of 
hydrogen ion concentration to which it is desirable to call atten- 
tion briefly: (1) Buffer effects and (2) the relation of hydrogen 
ion concentration to titration values. 

(1) Buffer effects. It has been found that many compounds 
have the property of affecting the results of the determination of 
the hydrogen ion concentration. When acid or alkali is added to 
a solution containing such compounds, the change in hydrogen ion 



674 Analysis of Dairy Products 

concentration is found to be less than would be expected for the 
known amount of acid or alkali added. Any substance which 
tends to prevent change in the original hydrogen ion concentra- 
tion of its solution, when an acid or base is added, is called a 
buffer or regulator. Proteins, salts, etc., may exercise such an 
effect. These effects must be determined for individual cases 
under specific conditions of concentration, temperature, etc. In 
tlie case of milk, the compounds acting as buffers are proteins, 
phosphates, citrates and carbonates. 

(2) Relation of hydrogen ion concentration to titration 
values. We have seen that hydrogen ion concentration is a quan- 
titative measure of the true acidity or alkalinity of a solution. 
The following question suggests itself to those who have used only 
titration methods for such measurements : What relations have 
the values determined by the measurement of the hydrogen ion 
concentration to those determined by titration? Without going 
into the full details, it is sufficient for our purpose to state that 
the neutral point of a solution, as determined by the use of an in- 
dicator, varies according to the indicator used and rarely coin- 
cides with the true neutral point shown by the hydrogen ion con- 
centration. For example, phenolphthalein under favorable con- 
ditions gives the neutral point of solutions as being somewhere 
between pH, 8 (Ch, IXIO-') and pH, 10 (Ch, IXIO-^), instead of 
at pH, 7 (Ch, lXlO-«) ; methyl red, between pH, 4(Ch, IXIO-') 
and pH, 6(1X10-5). It should be stated also that the determina- 
tion of hydrogen ion concentration shows extremely minute 
changes in the reaction of a solution, degrees of change which 
are not appreciable or measurable by the use of an indicator. 

ELEGTROMETRIC TITRATIONS OF SOLUTIONS CONTAINING 

PROTEIN. 

Before attempting hydrogen ion concentration determina- 
tions upon which conclusions of importance may be based the 
operator should consult the available literature on the subject, 
and by study and experiment become, as far as possible, familiar 
with methods and the many conditions and influences that are 
likely to affect results. This should be done no matter which 



Hydrogen Ion Concentration 



675 



method is used. The nature of the interferences will vary accord- 
ing to the problem but there is now available a large amount of 
material that may serve as a guide. The book, "The Determina- 
tion of HA^drogen Ions,*' by Clark, is one that no worker should 
fail to consult. 

Baker and Van Slyke's Method. — This method provides a 
means for making electrometric titrations of solutions containing 




Tig. 159. Apparatus foi* Making' Electrometric Titrations of Solutions 

Containing' Protein. 



proteins which is shorter and less complicated than methods pre- 
viously used. A cut of the apparatus used in the test is shown 
in Fig. 159. It consists of a 400 cc. wide mouthed bottle (V) 
calibrated in units of 50 cc. and provided with a cork stopper (S) 
which is divided into two equal halves that may be easily ad- 
justed in the neck of the bottle. The tube (E) for carrying the 
hydrogen electrode, and through which hydrogen may be passed 
into the bottle, is made by cutting a 10 cc. pipette in two in the 



676 AnaIvYsis of Dairy Products 

middle, then cutting one side of the lower edge off diagonally. 
The upper end of the tube is fitted through a hole in the stopper 
so that it may be raised and lowered as desired. A close fitting 
piece of pure gum rubber tubing attached to the upper end of 
the glass tube permits hydrogen to be passed into the apparatus 
when necessary. The hydrogen electrode (A) is about 1 cm. 
square and is made from platinum foil and welded to a piece of 
platinum wire about 15 cm. long. A slender piece of glass tubing 
extending down close to the electrode and annealed at each end 
around the wire covers the lower half of the wire. The upper 
end of the platinum wire is passed through a pin hole made 
through one side of the rubber tube after bending it across the 
top of the hydrogen tube. This makes a gas tight joint that 
permits the hydrogen electrode to be raised and lowered within 
the bell shaped lower end of the hydrogen tube and avoid having 
the electrode touch the inside wall. The electrode is prepared 
for use by cleaning it in hot chromic acid, washing with water, 
then giving it a uniform coating of platinum black. It is again 
dipped in hot chromic acid, washed and electrolyzed according to 
Clark's directions *\ All points on the electrode should give off 
bubbles with equal uniformity. 

The titration reagent is carried into the solution, from a bur- 
ette 30 cm. long and holding 10 cc, by means of the capillary 
glass tube (B). The capillary tube should fit snugly in the hole 
through the cork. The stirring apparatus (D) is the same as that 
described in Fig. 158, page 661. The opening through the cork 
should be just large enough to permit the rod to revolve freely. 
The tube (C) permits the addition of any special reagent, such as 
caprilic alcohol when necessary to prevent foaming. It may also 
serve, when made long enough, to siphon off a solution. It should 
then be located near the side wall away from the stirrer. The 
tube (K) contains saturated KCl solution. A roll of filter paper is 
placed in the small opening in the tip that enters the protein 
solution, and also, the upper surface of the KCl solution in the 
funnel is held slightly below the level of the protein solution in 
the bottle, in order to retard flow and diffusion. When the ap- 
paratus is used with a water bath the stop-cock in the KCl tube 
may be placed near the rubber connection at the top. 



Hydrogen Ion Concentration 677 

The folloMdiig additional pieces of apparatus are used: (a) 
A Leeds and Northrup potentiometer, type K; (b) a Leeds and 
Northrup galvanometer, type R, for zero instrument; (c) a one 
cell storage battery to supply the working current, which is 
checked with a Weston standard cell kept at constant tempera- 
ture. The current being measured originates in the chain, 
Hg|HgCl|0.1 N KC1| solution|Ho|Pt,|kept at constant temperature 
during each titration. 

Operation. The solution to be titrated is poured into the 
bottle or vessel (V) and water is added to make the desired 
volume. If a thermostat is used, the temperature of the solution 
should now be adjusted. Any bubbles present should be removed, 
which can be done by pricking them with a greased pin or by 
touching them with a fine capillary tube containing ether. The 
burette must be previously filled and all bubbles carried out of 
the delivery tube (B), the tip of which should be rinsed before it 
is put into the vessel. The filled delivery tube and the stirrer are 
placed in position within the vessel or bottle. The two halves 
of the cork stopper are placed in position together with the other 
parts. Care is taken to have the electrode drawn up within the 
protecting bell so that it does not touch the apparatus or solu- 
tion. Hydrogen is now permitted to flow rapidly in until the air 
is displaced, after which the stirrer is set in motion. This precau- 
tion is necessary because any bubbles of air that are stirred into 
the solution greatly retard the attainment of equilibrium. 

The electrode is now quickly lowered until it is entirely under 
the surface of the solution, and connections are then completed 
for the electrolytic circuit. Equilibrium is quickly reached ordi- 
narily, usually in 2 to 5 minutes after introducing the electrode. 
During the period approaching equilibrium, the stirrer should be 
run fast enough to kep a few bubbles of hydrogen constantly in 
suspension in the solution. Equilibrium is indicated by a con- 
stant E. M. F. for 2 minutes or more. When the E. M. F. is 
satisfactory, the desired amount of reagent is slowly introduced 
from the burette, during which the stirrer may be slightly ac- 
celerated to prevent coagulation but not fast enough to produce 
foam. After introduction of the reagent, readings are made once 
a minute until constant. When the amount of reagent introduced 



678 Analysis of Dairy Products 

is 0.5 cc. or less, equilibrium should be immediate. Titration is 
now continued until the desired number of values is obtained. 

In order to avoid marked dilution of the protein solution, titra- 
tions are made with use of N solutions of reagents, and thus the 
need of making corrections is avoided since the hydrogen ion 
concentration of the buttered solutions is inappreciably changed 
by the small degree of dilution under such conditions. The speed 
of the stirrer must be carefully regulated so as to cause little or 
no foam ; consequently, the addition of the reagent must be mod- 
erately slow; for example, about 1 cc. in 2 minutes in the ease of 
N HCl with solutions containing 1 per cent of casein. 

The accuracy of the electrometric titration can be checked, 
when completed, by redetermining the final E. M. F. value of the 
titration of the solution with a Clark electrode. If agreement is 
not close, the results of the titration should be discarded and the 
operation repeated. In our work agreement is nearly always ob- 
tained. 

Baker and Van Slyke's Colorimetric Method^" for Determin- 
ing' Hydrogen Ion Concentration in Milk: Preparing the indi- 
cator: Dissolve finely ground crom-cresol purple in water using 
0.1 g. for 100 cc. of water. Heat on a water bath to hasten solu- 
tion to saturation. Cool to room temperature and filter. The 
saturated solution contains about 0.09 per cent of the dye. 

Apparatus: (a) A burette with delivery so controlled that 
each drop measures 0.05 cc. of indicator, (b) Test tubes made of 
Pyrex glass, flat-bottomed, and about 4 inches long and Yz inch in 
diameter. The tubes hold about 8 cc. and should be uniform in 
color and thickness of wall, (c) Test tube rack so constructed 
that the tubes may be held in a line side by side without conceal- 
ing any of the milk column, (d) Pipettes graduated at 3 cc. for 
measuring the milk into the test tubes. 

Operation: Place the test tubes in the holder, fill the burette 
with the brom-cresol solution and adjust the stop-cock to deliver 
about 1 drop in 2 seconds, each drop measuring 0.05 cc. Allow 1 
drop of the indicator to flow from the burette into each tube 
without touching the side walls while it is falling. Place 3 cc. of 
milk from the first sample in the first tube. Mix the milk thor- 
oughly Avith the indicator, then measure 3 cc. of the second sample 



Hydrogen Ion Concentration 



679 



into the second tube, mix and proceed in a similar way for all 
samples. 

Compare the shade of color obtained with each sample with a 
color standard made up as follows : Select a sample of normal 
milk containing between 3 and 4 per cent of fat and having an 
acidity that requires nearly, but not more than, 1.8 cc. of tenth- 
normal alkali for 10 cc. of the milk, using 0.5 cc. of a neutral alco- 
holic phenolphthalein solution as indicator. 

Arrange 8 test tubes and place 10 cc. of the normal milk in 
each. Run tenth-normal NaOH solution into them as follows : 

Tube No 1 2 3 4 5 6 7 8 

Drops of tenth-normal NaOH... 2 4 6 8 10 12 14 

In addiiig the alkali from the burette take all of the precau- 
tions that were observed in measuring the brom-cresol purple into 
the first set of test tubes. Mix the alkali and milk thoroughly. 
Arrange another set of 8 test tubes like the smaller ones used in 
the first instance and number them from 1 to 8, From each test 
tube containing the milk and alkali mixture measure 3 cc. into 
the smaller test tube that is numbered correspondingly, and add 
to each, one drop of the brom-cresol purple solution and mix well. 
Compare the color of each tube containing the unknown milks 
with the standard set of tubes containing the milk, alkali and 
brom cresol mixture. 

The reaction color in each tube corresponds approximately to 
the following pH values. 

TABLE 118. 



No. in series 


1 


2 


3 


4 


5 


6 


7 


8 






cc. of 0.1 N NaOH used.. 




6.5 

to 

6.6 


0.1 

6.6 

to 

6.67 


0.2 

6.67 

to 

6.75 


0.3 

6.75 

to 

6.82 


0.4 

6.82 

to 

6.90 


0.5 
6.90 

to 
6.98 


0.6 

6.98 

to 

7.05 


0.7 
7.05 
to 
7.13 


Symbol for reaction color 


N 


N-1 


N-2 


N-3 


N-4 


N-5 


N-6 


N-7 



As a matter of convenience in tabulating results, we append 
a series of symbols to indicate the pH values, N standing for nor- 



680 Analysis of Dairy Products 

mal reaction and N followed by the minus sign and figures rang- 
ing from 1 to 7, indicating decreased acidity corresponding to 
increasing pH values. 

Such samples as appear to be abnormal by showing a deeper 
blue shade of color, indicating decreased acidity, are open to the 
suspicion of being watered, or skimmed, or treated with alkaline 
salts, or containing excessive numbers of leucocytes as in milk 
from diseased udders. Which of these suspicions is justified can 
be ascertained by the determination (1) of the freezing-point, (2) 
of the percentage of milk-fat or the ratio of fat to proteins, (;}) 
of the specific gravity, (4) of the total solids, (5) of the presence 
of alkaline salts, especially sodium bicarbonate and borax, (6) of 
the numbers of leucocytes by direct microscopic examination by 
Breed's method, and (7) of COo by Van Slyke's method*' modi- 
fied by us for use in connection with milk. 

In the case of samples showing a color lighter than normal 
with the brom-cresol purple solution, indicating an abnormal de- 
gree of acidity, there is awakened the suspicion of bacterial acid 
production, the presence of formaldehyde, overheating, or the 
presence of added acid salts ; or tlie lighter color may be due to 
a high percentage of milk-fat. Which of these indications is 
correct is determined as follows : A direct count of the number of 
bacteria is often sufficient. If this fails to show the presence of 
excessive numbers of bacteria, then a test should be made for the 
presence of formaldehyde, and if this is not present, the percent- 
age of milk-fat is determined ; and, further, in order to see if the 
light color is due to overheating, the determination of carbon 
dioxide should be made and Storch's test may also be applied. 

McCrudden's^'' Colorimetric method for determining" hydrogen 
ion concentration. — This method is primarily for use in bacterio- 
logical work. 

Standard solutions: Prepare "tenth molecular solutions of 
KH.PO4 (13.62 grams potassium phosphate, monobasic, anhy- 
drous, Merck's reagent, to the liter) and Na^.HPO^ (14.21 grams 
sodium phosphate, anhydrous, Merck's reagent, per liter). From 
these the following twelve standard solutions are prepared: 



Hydrogen Ion Concentration 

TABLE 119. 
pH of Phosphate Solution. 



681 





M 


M 






c. c. JO 


c. C. J^ 


pH 




Na,HPt), 


KH,PO, 






8 


93 


5.8 




12 


88 


6.0 




19 


81 


6.2 




27 


73 


6.4 




37 


63 


6.6 




49 


51 


6.8 




61 


39 


•7.0 




73 


27 


7.2 




82 


18 


7.4 




89 


11 


7.6 




94 


6 


7.8 




97 


3 


8.0 



The Reading. — To determine the hydrogen ion concentration of 
an unknown solution coming within the limits of Ph=6.8 to 8.2, 
add to it five drops of a 0.03 per cent solution of phenol red and 
compare the resulting color with that obtained by adding the same 
amount of indicator to 5 cc. of each of the standard phosphate 
solutions diluted with 10 cc. of water. Between the limits Ph= 
5.8 to 6.8 the indicator brom-cresol purple- — five drops of a satur- 
ated solution — should be used. (The standard solutions with in- 
dicator in them will keep several weeks if tightly stoppered.) 

The Comparator. — The color comparison can be made in large 
clear glass test tubes. To overcome the effect of turbidity, such 
as occurs in bacteriological media, the unknown solution is di- 
luted to a moderate extent, say to three times its volume, and the 
test tubes are arranged in a device called a comparator. The 
device consists of a block of wood containing 6 perpendicular 
holes large enough to carry the test tubes. Three other holes are 
then bored horizontally through the block from side to side, so 
that one can look right through each pair of test tubes in series. 
When the solutions are arranged as indicated in each case the 
light reaching the eye has passed through solution containing 
indicator and solution containing turbidity. In the case of the 
unknown, one solution contains both turbidity and indicator; in 
the case of the standards the turbidity and indicator are in sepa- 
rate solutions. 



682 Analysis of Dairy Products 

Adjusting reaction of culture media. Most bacteria grow best 
in media whose pn lies between 7.2 and 7.6. To adjust media to 
any desired hydrogen ion concentration N/10 alkali is added drop 
by drop to five cc. of the somewhat diluted media containing in- 
dicator until, as shown by comparison with the standards, the 
desired hydrogen ion concentration is reached. From the amount 
of alkali required for five cc. the amount needed for the whole 
batch of media can then be calculated. Sterilization of the media 
shifts the pn about 0.2 toward the acid side. Allowance should be 
made for this. 

Clark and Lubs Table.^" 

Eange pH 

Thymol blue (acid range) 1.2 — 2.8 

Thymol blue (alkaline range) 8.0 — 9.6 

Brom phenol blue 2.8 — 4.6 

Methyl red 4.4—6.0 

Propyl red 4.8 — 6.4 

Brom-cresol purple 5.2 — 6.8 

Brom-thymol blue 6.0 — 7.6 

Phenol red 6.8 — 8.4 

Cresol red 7.2 8.8 

Cresol phthalein 8.2 — 9.8 

The indicators in either powdered form or stock solution may 
be purchased from chemical supply houses. 

Thymol blue may be made up for use in .04% solution. Its 
color change is from red to yellow in the acid range and from 
yellow to blue in the alkaline range. 

Brom-Phenol blue is made up to .04%^ solution. Its color 
change is from yellow to blue. 

Methyl red is made up to .02% solution. Its color change is 
from red to yellow. 

Brom-cresol purple is made up to .04%; solution. Its color 
change is from yellow to purple. 

Brom-thymol blue is made up to .04% solution. Its color 
change is from yellow to blue. 

Phenol red and cresol red are made up to .02% solutions. 
Their color change is from yellow to red. 

Cresol phthalein is made up to .02% solution. Its color change 
is from colorless to red. 



References 683 

REFERENCES. 

lU. S. Dept. of Agri., Bui. 134, 1911. 

2 M'clnerney, Prof. T. J., Cornell Univ., Ithaca, N. Y. 

' Association of Official Agricultural Chemists. 

* Walker, W. O. A Rapid Method for Determining the Percentage of 
Casein in Milk. Jour. Ind. Eng. Chem. Vol. 6, No. 2, 1914. 

5 Hart, E. B., A Simple Test for Casein in Milk and its Relation to the 
Dairy Industry, Wis. Exp. Sta. Bui. 156, 1907. 

" Butterman, S. The Influence of the Method of Manufacture on the Use 
of Casein in Glue Making. Jour. Ind. and Eng. Chem., Vol. 12, No. 12, p. 141, 
1920. 

'' Dahlberg, A. O. The Manufacture of Casein from Buttermilk or Skim- 
milk. U. S. Dept. of Agri. Bui. No. 661, Bu. Ani. Ind. 1918. 

8 Van Slyke, L. L. N. T. Agri. Exp. St. Bui. 215, 102. 

* White. W. B., Chemist, Ithaca Laboratory, Division of Foods and Mar- 
kets, N. Y. Unpublished results, Cornell University. 

i" Analyst, 1910, 29, 248. 

" Bigelow and McElroy. Jour. Am. Chem. Soci. 15, p. 668. 

1- Rothenfusser. Zeitz. Nahr. Genussm., 16, 51, 1906. 

1" Compt. rend, de I'Acad. des Sciences, vol. CXXXIV, p. 1592. 

" Supplee, G. C, Bellis. B., Citric Acid Content of Milk and Milk Products 
J. Biol. Chem. 48, 2, 1921. 

15 Beau M. (Revue Generale du Lait, 1903-4 P. 385) as modified by Dobbte. 
(Reports of the Local Gvt. Board on Public Health and Medical Subjects. 
New series No. 116, p. 184, London 1918. 

"Dahlberg, A. O. and Garner, H. S., Bui. 944, Bu. An. Ind., U. S. Dept. 
Agr 1921. 

" Ayers, S. H. and Johnson, W. T. Jr. The Alcohol Test in Relation to 
Milk. U. S. Dept. Agri. Bui. 202, p. 35, 1915. 

18 Evenson, O. L. A Color Test for "Remade Milk and Cream." Jor. 
Dairy Sci.. Vol. V, No. 1, 1922. 

1* Robinson, R. H. The Determination of Formaldehyde in Solution. 
Chemist-Analyst. No. 29. Apr. 1919. 

-0 Wilcox, E. V. Production and Inspection of Milk. Hawaii. Agri. Exp. 
Sta. Bui. 1912. 

^iHunziker, Otto P. The Butter Industry, 1920. 

22 Methods of A. O. A. C. Bui. No. 107. (Revised) 1912. 

2'' Chem. Zeit. 1899, 23, 312, Abs. Analyst, 24, p. 206. 

2'' Patrick, G. E. Household Tests for the Detection of Oleomargarine and 
Renovated Butter, Farmer's Bulletin 131. 

25 Jour. Ind. Eng. Chem. 12. 366-8, 1920. 

28 Dingler's Polyt. Jour., 25, 1884, p. 281. Zeits. Unters. Nahr. Genussm., 
4, 1901, p. 913. 

27 Congdon, L. A. Jour. Ind. Eng. Chem. Vol. 7, No. 7. 1915. 

28 Cook, A. A. and Woodman, A. G. Jour. Ind. Eng. Chem. Vol. 10, No. 7, 
1918. 

2»Bur. of Chem., Bull. 122, p. 52., 132, p. 122. 

30 Am. Food Jour. Dec. 1916. P. 621. 

»i Clark, A. W. and DuBois, L. "Jelly Value" of gelatin and glue, Jour. 
Ind. Eng. Chem. Vol. 10, No. 9, 1918. 

»2 Jour. Ind. Eng. Chem. Vol. 8, No. 8, 1916. 

=» Hammer, B. W. and Johnson, A. R. The Specific Heat of Milk and Milk 
Derivatives. Agri. Exp. Sta., Iowa State College of Agriculture and Mechanic 
Arts, Research Bui. No. 14, 1913. 

^* Richmond. Dairy Chemistry, 1914, London, Charles Grifl^n and Com- 
pany, Limited. 

•■'5 Barthel, translated by Goodwin. Milk and Dairy Products, 1910, Lon- 
don. MacMillan and Co., Limited. 

38 Atkins. Chem. News. 1908, 97, 241. 

»7 Stocking. Manual of Milk Products. 1917, N. Y. McMillan Co. 

38 Grimmer. Chemie and Physiologic der Milch, 1910. 

3» Heineman. Milk, 1919, Philadelphia, W. B. Saunders Company. 

*« Chem. Bui. Vol 7, No. 4, 1920. 

" Van Slyke, L. L. and Baker, J. C. Studies Relating to Milk Tech. Bui. 
No. 65, N. Y. Agr. Exp. Sta. 1918. 

*2 Arrhenius, S. Ueber die Dissociation in Wasser geloesten Stoffe. Z. 
physik. Chem. 631, 1887. 

4»Bigelow, W. D. and Cathcart, P. H.; Bui. 17-L, 1921. Nat. Canners Assn. 

" Baker, J. C. and Van Slyke, L. L. N. Y. Agri. Exp. Sta., Geneva, N. Y. 
Tech. Bui. No. 65, 1918. 

•■5 Clark, W. M. Jor. Biol. Chem. 23; 475, 1915. 

*« *7 Baker, J. C. and Van Slyke, L. L. J. Biol. Chem. 2, 337, 357, 1919. 

*8 McCrudden, F. H., U. S. Public Health Rpt. Vol. 37, No. 7, 1922. 
*» Clark, W. M. and Lubs, H. A., J. Bact. 2, 1, 109, 191. 



CHAPTER XVIII 

THE PURPOSE AND ADVANTAGE OF THE 

VACUUM PAN IN THE DAIRY 

INDUSTRY 

The use of the vacuum pan in the dairy industry dates back 
to the invention of Gail Borden to whom patent Avas granted in 
1856. The historical side of the milk condensing industry is ably 
discussed by Prof. 0. F. Hunziker, in "Condensed Milk and Milk 
Powder," to which the reader is referred. 

The purpose of the vacuum pan in the dairy industry is 
primarily to remove water from dairy products, thus making it 
possible to manufacture a new class of products. The advantages 
derived by evaporating in vacuo as against evaporating in the 
open air are numerous, the principal of which are the following : 

(a). The Economic Advantage. To evaporate one pound of 
water from milk in the open air, starting with a temperature of 
60° F. and calculating the specific heat of milk at 0.93 requires 
the expenditure of 1107 B. T. U. To remove the same amount 
of water under vacuo at 140° F. requires the expenditure of 
only 1040 B. T. U., or a saving of 6.4 per cent in heat units. 

(b). The rate of evaporation in vacuo is very much greater 
than in the open air, due to the fact that the boiling point de- 
creases with lowering pressures. This is illustrated best by 
reference to Table 120, which is based upon the table by 
Hunziker^ entitled: "Boiling points of water at different 
vacua." The last column in Table 120 is based upon a careful 
experiment the object of which was to determine the rate of 
evaporation under different vacua. Under good conditions of 
practical operation it is iisually possible to evaporate about 30 
pounds per hour, per square foot of heating surface in the vacuum 
pan. Under the vacuum usually obtainable in practice, namely, 
about 26 inches of mercury as shown in Table 120 and upon the 

[684] 



Boiling Points 685 

TABLE 120. Relation Boiling Points Vacuo and Rate of Evaporation. 



Absolute 
pressure per 
square inch 


Vacuum inches 

of mercury 

column 


Vacuum 
millimeters 
of mercury 

column 


Boiling points 
of water at 
degrees F. 


Boiling points 
of water at 
degrees C. 


Pounds of water 

evaporated per 

hour, per sq. ft. 

of heating 

surface. 

Approximate 

values 


14.720 






212.00 


100.00 


8.2 










14.010 


1.42 


36 


209.55 


98.5 


9.4 


13.015 


3.45 


88 


205.87 


96.8 


11.0 


12.015 


5.40 


139 


201.96 


94.3 


13.0 


11.020 


7.52 


191 


197.75 


91.9 


14.7 


10.020 


9.56 


243 


193.22 


89.5 


16.5 


9.020 


11.60 


295 


188.27 


86.75 


18.2 


8.024 


13.63 


346 


182.86 


83.7 


20.0 


7.024 


15.67 


398 


176.85 


80.5 


21.7 


6.024 


17.70 


450 


170.06 


76.8 


23.4 


5.029 


19.74 


502 


162.28 


72.5 


25.2 


4.029 


21.78 


553 


153.01 


67.2 


27.0 


3.034 


23.81 


605 


141.52 


60.8 


28.7 


2.034 


25.85 


657 


126.15 


52.3 


30.2 


1.040 


27.88 


708 


101.83 


38.7 


Not determined 


.980 


28.00 


712 


100.00 


37.8 


•• 


.735 


28.50 


724 


90.00 


32.2 


•• 


.544 


28.89 


734 


80.00 


26.7 


•' 


.402 


29.18 


741 


70.00 


21.1 


•' 


.294 


29.40 


747 


60.00 


15.6 


" 


.216 


29.56 


751 


50.00 


10.0 


" 


.162 


29.67 


754 


40.00 


4.4 


" 


.127 


29.74 


756 


32.00 







686 



The Vacuum Pan 



graph under Fig. 160, the quantity of water possible to evapo- 
rate per square foot of heating surface, decreases rapidly with 
a decrease in the vacuum. In other words, it would take nearly 
four times as long to evaporate the same amount of water at 
air pressures than under 25.85 inches of mercury vacuum. 




5. WATER EVAR PER HOUf^ PER 3Q. FT 



TING 6URFACE 



Pig-. 160. 



Founds of Water Evaporated per Hour per Square Poot of Keating' 
Surface, Under Different Pressures in the Vacuum Fan. 



(c). The greatest advantage is probably the fact that under 
vacuum the various constituents of milk undergo no changes in 
flavor, color or chemical composition, owing to the low tem- 
peratures employed, and the short time necessary to hold the 
milk under heat during the condensing operation. It is these 
advantages that have made it possible to manufacture and market 
many new products of great commercial importance, that were 
unknown before the advent of the vacuum pan in the dairy in- 
dustry. 

DESCRIPTION OF THE VACUUM PAN. 

Many different types of vacuum pans are upon the market, 
and in use. The reader is referred to "Condensed Milk and 
Milk Powder" by Prof. 0. F. Hunziker,^ for a description of 



MojoNNiER Type Pan 



687 



these various types. For the purpose of enunciating principles 
the Mojonnier type of vacuum pan is the only one explained 
herewith, and illustrated under Fig. 161. 



HANDHOLE 



CONDENSER 



VACUUM LINE 8c 

CONDENSATION 

DRAWOFF 

PEEP HOL 
LIGHT 

DOME 



WAIST 



VACUUM GAUGE 
AIR BRAKE 



MANHOLE & 
PEEP HOLE 




MILK 
INLET 
COCK 



STEAM COI 



JACKET 



STRIKING CUP 



MILK DRAW-OFF COCK 



Pig. 161. Mojonnier Type Vacuum Pan. 



All vacuum pans consist essentially of five principal parts, 
together with the necessary control devices. The design of each 



688 The Vacuum Pan 

of these parts has a large bearing upon the subsequent operation 
of the pan itself. These various parts are as follows : 

(a). The Condenser. It is here that the vapors which are 
evaporated from the milk are condensed to the liquid form. This 
should be so designed and proportioned as to remove the in- 
coming vapors in the least time and with the use of the least 
possible amount of water. 

(b). The Dome. This supports the condenser, and upon it 
are usually fastened the majority of the accessories such as the 
manhole, vacuum gauge thermometer, eye glasses, and buttercup 
valve. It should be sufficiently strong to support the condenser, 
and the atmospheric pressure. The opening into the condenser 
should be large enough to permit of the free and ready passage 
of the expanded vapors from the pan into the condenser. One 
pound of saturated steam at 126.27° F. under 25.88 inches of 
mercury vacuum will occupy 173.6 cubic feet as against 26.36 
cubic feet for an equal weight of saturated steam at 212° F. 
The shape of the dome is also a factor in helping to prevent 
entrainment of milk solids into the condenser. The oval dome 
as shown upon the illustration under Fig. 161 is of the proper 
design to help prevent such losses. 

(c). The Waist. This part requires the use of heavy copper, 
in order that it may stand up properly under the work that is 
required of it. A frequent mistake is to make this part too low 
thus 'making a condition that favors entrainment losses. 

(d). The Jacket. This is supplied either with double copper 
jacket or with the outside jacket made of cast iron. The double 
copper jacket helps to prevent water leakage at the coil joints. 
This is the cause of considerable trouble in the case of pans fitted 
with cast iron jackets, owing to the unequal coefficient of expan- 
sion of the two metals, — that of copper being nearly 50 per cent 
larger than that of cast iron. A deeply dished jacket presents 
many advantages over the shallow type. It makes for greater 
strength, and it also makes it possible to set the coils low, and 
thus begin the evaporation in a minimum of time. This also 
helps to prevent entrainment losses. 

(e). The Coils. The proper size, quantity and design of the 
coils in a large measure determine the success of the pan. The 



Pan Sizes and Capacities 689 

openings into the coils should be large enough to permit of the 
use of exhaust steam. Coils of the basket type help to keep the 
level of the milk low, thus preventing entrainment losses. The 
spiral shape of basket type coils also permits the water which 
is condensed from the steam to flow out rapidly to the outlet. 

COMMERCIAL SIZES, AND CAPACITIES OF VACUUM PANS IN 
TERMS OF BOTH RAW AND FINISHED PRODUCTS. 

Various sizes of vacuum pans are obtainable, the choice of 
size being governed by the quantity of product that it is desired 
to handle. Table 121 lists the most commonly used sizes. Like- 
wise it gives the approximate hourly rating of the various sizes 
in terms of both raw and finished products. The list is confined 
to the most common of the commercial condensed milk products. 
The ratings are very conservative, and under the most efficient 
operation these can be increased as much as 20 to 25 per cent. 
- One example will serve to illustrate the method of calculation 
used. 

Example : — What is the capacity of a vacuum pan, diameter 3 
feet, making sweetened condensed whole milk? Whole milk 
tests 3.43 per cent fat, and 12.0 per cent total solids. Finished 
product tests 8.0 per cent fat, 20.0 per cent milk solids not fat, 
and 46.0 per cent sugar. Pan has capacity to remove 1000 lbs. 
water per hour. 

Solution : — 
28.0 -~ .12 = 233.2. lbs. whole milk required for every 100 lbs. 

finished product. 
233.2 -f- 46 = 279.2, lbs. total products required for every 100 lbs. 

finished product. 
279.2 — 100 =■ 179.2, water removed for every 100 lbs. 

finished product. 
1000 ^ 179.2 X 100 — 558, lbs. finished product per hour. 

558 X .28 

— =1302, lbs. whole milk per hour. 

Proof : — 
558 X .466 = 256, lbs. sugar. 
1302 + 256 — 1558, lbs. total raw products. 
1558 — 558 = 1000, lbs. water removed per hour. 



690 



The Vacuum Pan 



cu 



m 






Finished product testing 
10.0 per cent fat 
14 . per cent sugar 

. 5 per cent gelatin 
11.5 per cent milk solids not fat 
36.0 per cent total solids 



Whole Milk testing 3.67 per cent fat and 
12.00 per cent total solids 






o A 






Finished product testing 25.0 per cent 
total solids 



Buttermilk testing 8.80 per cent total 
solids 



Finished product testing 26.40 per cent 
total solids 



Skim-milk testing 8.80 per cent total 
solids 



Finished product testing 8.00 per cent 
fat and 26.15 per cent total solids. 



Whole milk testing 3.6 per cent fat and 
12.00 per cent total solids 



Finished product testing 28.0 per cent 
milk solids and 74.0 per cent total 
solids 



Whole milk testing 3.43 per cent fat and 
12 per cent total solids 



Finished product testing 28.0 per cent 
milk solids and 70.0 per cent total 
solids 



Skim-milk testing 8.8 per cent total solids 



Pounds water evaporated per hour 



Diameter of vacuum pan 



Vacuum Pump 



691 



THE VACUUM PUMP. 

Two different classes of vacuum pumps are available : name- 
ly, the dry vacuum and the wet vacuum. In the dry vacuum 
pump the condensed vapors do not discharge through the pump 
as in the case of wet vacuum pump. In the milk condensing in- 
dustry the wet vacuum pump is now almost universally used, 
probably the only exception being experimental plants that desire 
to study the condensation. 




Courtesy J. J. ReiUy Co. 
Pigr. 162. Straight Type Wet Vacuum Pumps 

In turn, there are several types of the wet vacuum pump, 
namely the straight type as illustrated under Fig. 162 ; the 
crank and fly wheel type, and types that are either belt driven or 
driven by direct attached motors. The choice of type is govern- 
ed entirely by local considerations, the principal of which is the 
unit power cost. The crank and fly wheel type is the most effi- 
cient from the standpoint of steam consumption, but its first cost 
is the largest of any of the common types, and it is bulky and 
occupies much floor space. "When the exhaust steam is used in 
the pan, in the end the straight line pump is equally economical, 
and that is the type that is by far the most commonly used. 



692 



The Vacuum Pan 



The correct sizes of vacuum pumps to use upon various sizes 
of pans, is indicated in Table 122. This comprises only pumps 
of the straight line type. In the case of 3 feet diameter and 7 
feet diameter pans a choice of sizes is given. At low altitudes the 
smaller sizes will render good service, while at higher altitudes, 
the larger sizes will usually prove to be the more satisfactory. 

TABLE 122. 
Sizes of Vacuum Pumps Recommended for Various Sizes of Vacuum Pans. 



Size 

of 

vacuum 

pan 


SIZE OF VACUUM PUMP 


Size 

of 

vacuum 

pan 


SIZE OF VACUUM PUMP 


Diameter 
of steam 
cylinder 


Diameter 
of water 
cylinder 


Length 

of 
stroke 


Diameter 
of steam 
cylinder 


Diameter 
of water 
cylinder 


Length 
stroke 


3'0" 


7" 


10" 


10" 


5'0" . 


10" 


16" 


20" 


3'0" 


8" 


10" 


12" 


6'0"6'6" 

and 7' 0" 


12" 


18" 


20" 


S'O' 


8" 


12" 


12" 


7'0" 


14" 


20" 


20" 


4' 2" 


10" 


14" 


16" 





















STEAM PIPING UPON VACUUM PAN TO USE EITHER LIVE OR 

EXHAUST STEAM. 

Numerous methods are employed to introduce steam into the 
coils and jackets of vacuum pans, and likewise to remove the 
condensation from the same. Wherever any exhaust steam is 
available this should be used, and the deficiency made up with 
live steam. 

In Fig. 163 a complete scheme of piping is shown whereby 
either live or exhaust steam can be used to operate the vacuum 
pan. The scheme is the simplest and at the same time the most 
satisfactory one possible. Exhaust steam can be utilized to the 
extent of the quantity available. If more exhaust steam is avail- 
able than the pan can utilize, the relief valve will operate and 
permit the escape of the surplus exhaust steam either into the 
open air, or into the feed water heater. If no exhaust steam is 
available, the lower end of the low pressure header can be closed 
with a blank flange. If exhaust steam is used, the coil openings 



Vacuum Pan with Piping 



693 



iTEAM PRESSURE. RE.GULATOR-. 



LIVL STEAM LINi- 



LIVE: 6TLAM 5DPFLV VALVL^ 
OUTtR COI L CONTROL VALVL- 

SAFE-TYPOPVALVt- 

i nnlr coi l cont rol valve.- 
lowe:r coil control valvl- 



EJ(HAU5T3TtAMLINt-- 



STEAM SLPA1?AT0R- 




Tig. 163. Fipingr Scheme Sug-gested for Connectingf a Vacuum Fan to 
Operate Upon Either or Both Iiive and Exhaust Steam. 



694 The Vacuum Pan 

should be large enough to admit the increased volume due to the 
low pressure of the steam. Equal weights of saturated steam 
will occupy about five times more space at 5 pounds than at 100 
pounds pressure. 

At the discharge from the pan single traps are provided for 
each coil and the jacket. Good makes of either thermostatic or 
gravity traps will operate with equal satisfaction. 

The condensation from the trap, in turn, discharges into a re- 
ceiver which is connected to a boiler feed pump, which pumps 
the condensation directly into the boilers as fast as it accumu- 
lates. 

The suggested scheme of piping makes it possible to condense 
the milk with the smallest number of heat units, and with the 
expenditure of the smallest amount of labor. 

Suggested Location of Contro] Devices. 

The location of all the control devices is also indicated in 
Fig. 163. The proper selection and location of these several 
devices will do much to promote the efficient operation of the 
pan. Local conditions frequently make it necessary to modify 
the locations shown. 

RELATION OF WATER REQUIRED IN THE CONDENSER, TO 

THE WATER REMOVED FROM THE MILK IN THE 

VACUUM PAN. 

The quantity of water required to condense the steam vapors 
arising from the milk in the vacuum pan, varies under several 
different conditions. Table 123 gives the number of pounds 
of water required in the condenser for every pound of water 
evaporated in the vacuum pan under many different conditions 
of operation. The values given are the theoretical values. In 
practice the total requirements under the same conditions as 
named under Table 123 are about five per cent higher than 
the values given. This statement is based upon the results of 
carefully conducted experiments made to determine this point. 

The method of calculation used is illustrated by the follow- 
ing example : — 

Example : — ^How many pounds of water, temperature 55° F., 
will be required to condense one pound steam in vacuum pan. 
Water vapors 140° F. Condensation 130° F.? 



Water Rijouirements 



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696 The Vacuum Pan 

Solution : — 
(a). 140 — 130=: 10, B.T.U. required to cool vapors to tem- 
perature of condensation. 

966 B.T.U. required to evaporate one pound of water in the 
pan. 

966 -|- 10 = 976, B.T.U. required for evaporation of one pound 
of water. 

(b). 130 — 55 =r 75, B.T.U. available per pound water sup- 
plied in the condenser. 

976 

= 13.0, pounds water required per pound steam evapo- 

75 

rated m the pan. 

The percentage increase in the volume of water required un- 
der various conditions of operation, as compared with water at 
a temperature of 35° F. is given in Table 124. This table is 
based upon the values given in Table 123. One example will 
serve to illustrate the derivation of the table. 

Example :^ — With the water vapors in the pan at 140" F., and 
the condenser water at 130° F., 10,3 pounds of water at 35° F. 
are required for each pound of water vapor removed. Using 
water at 55° F., 13.0 pounds are required, per pound of water. 
What percentage increase in volume of water is required at 
55° F.? 

Solution : — 
13.0 — 10.3 = 2.7, pounds increase. 

2.7 divided by .103 = 26.21, per cent increase. 

The following conclusions are based upon the values given 
in Tables 123 and 124. 

(a). The warmer the water entering the condenser, the larg- 
er the volume required. The most efficient use is made of the 
"^ndenser Avater, when the temperature of the water vapors in 
+*>o, pan is maintained at about 140° F. 

(b). The greater the difference between the temperature of 
fhe water vapors in the pan, and the outgoing water temperatures 
in the condenser, the greater will be the volume of water re- 
quired. 



Water Requirements 



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698 



The Vacuum Pan 



The increase in the volume of water required due to the de- 
crease in the temperature of the water vapors in the pan is in- 
dicated in Table 124. This table is based in large part upon the 
results given in Table 123. One example will suffice to illustrate 
the method of calculation used. 

Example : — With the water vapors in the pan at 140° F. ; the 
incoming condenser water 35° F. ; and the outgoing condenser 
water 130° F., 10.3 pounds of water are required for each pound 
of water vapor removed. 

How much more water will be required if the temperature of 
the water vapors is 135° F. and the outgoing condenser water 
125° F.? 

Solution : 
10.8 — 10.3 =: .5, pounds more water required. 
.50 -~ 10.3 =: 4.85, per cent more water required. 

Table 125 shows that the higher the temperature of the 
water vapors in the pan (not exceeding 140" F.) the 'less the 
quantity of water required in the condenser. This rule applies 
regardless of the temperature of the incoming water. 

TABLE 125. 

Percentage Increase in Volume in Excess of Water Required When the Pan 

Temperature is 140° F. In All Cases the Difference Between the Incoming 

and the Outgoing Condenser Water Temperatuie is 10° F. 



Temperature 


Temperature (F) Steam Vapors in 


Pan 


(F) water 
entering 










135° 


130° 


125° 


120° 


condenser 


Per cent 


Por cent 


Per cent 


Per cent 


35° 


4.85 


11.65 


18.44 


26.21 


45° 


6.09 


13.04 


20.87 


30.43 


55° 


6.92 


15.38 


25.38 


36.15 


65° 


8.67 


18.00 


30.00 


44.66 


75° 


10.17 


22.60 


37.85 


57.63 


85° 


12.44 


28.57 


49.77 


79.72 


95° 


17.20 


39.78 


74.91 


133.33 


105° 


25.13 


66.92 


152.82 


400.51 



STEAM REQUIRED TO CONDENSE MILK IN THE VACUUM PAN. 

The total heat units required to condense milk is the sum 
of the heat units required to forewarm the milk in the hot wells, 



Hot Wklls 699 

plus the heat units required to evaporate the water in the vac- 
uum pan. This will vary under several different conditions, the 
principal factors causing variations being, (a) the type of hot 
wells, or method of preheating used; (b) the type, efficiency, and 
general operating condition of the pan used; (c) the temperature 
and the composition of the product that is to be condensed; (d) 
the temperature of the steam used both at the hot wells and in 
the vacuum pan. 

Type of hot well. As described in Chapter XIX, the two 
types of hot wells in general use are the plain and the 
jacketed. In the plain type the heating of the milk is accom- 
plished by introducing live steam directly into the milk. In 
the jacketed type the heat is transmitted to the milk through the 
jacket, in which case no steam needs to be condensed directly 
into the milk. It is sometimes the practice however, to heat the 
milk through the jacket up to about 180° F., and then to com- 
plete the heating up to 210° F. by means of both the jacket and 
live steam introduced directly into the milk. 

Table 126 shows the amount of steam condensed into milk at 
various initial temperatures, heated to both 140° F. and 210° F., 
and using steam of various pressures, in plain type hot M^ells. 
The percentages indicated in the table prove plainly that this 
is a considerable factor in the efficient operation of a vacuum 
pan. The figures given apply only to whole milk of the test 
indicated. The values will vary with the specific heat of the 
product that is being heated in the hot well. In the case of the 
fresh milk covered by the table, the specific heat was calculated 
at 0.935. 

Table 127 gives the pounds of steam required both to fore- 
warm and condense the raw materials necessary to make one 
pound of various condensed milk products. The values are given 
covering various conditions of operation, particularly with re- 
gards to method of forewarming employed. The table also gives 
the pounds of steam required, per pound of water evaporated 
out of the fluid milk, together with the percentage increase in 
the use of steam when using plain type, instead of jacketed type 
of hot wells. 



700 



The Vacuum Pan 






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Steam Requirements 701 

The method of calculation employed, to arrive at the values 
given in the table, was as follows : — 

(1). To find steam required to forewarm using plain hot 
wells : — 

[(210 — 60) X 0.935] X 2.179=:.144, pounds 

(forew. tem- (milk (sp. heat (conden- steam to 

perature F.) temp. F.) milk) sation) forewarm 

in plain 
wells. 
1151.5 — 179 

(B. T. U. in steam (B. T. U. in water 
at 5 lbs.) at 210° F.) 

(2). To find steam required using jacketed Avells : — 
Added 10 per cent to value obtained under (1), for radiation. 
(3). To find steam required to condense using plain wells: — 

26.65 

= 2.179, pounds whole milk required per pound fin- 

^^•^^ ished product. 

(2.179 — 1.00) + .144 = 1.323, pouncjs water evaporated. 
1.323 X 966 = 1278. B. T. U. required. 

[(210—140) X .935] X 2.323 = 152. B. T. U. in milk after 
forewarming. 

1278 — 152 

= 1.126, pounds steam required to con- 

1151.5 — 151.5 

dense using plain hot wells. 

(4). To find steam required to condense using jacketed hot 
wells. 

26.65 

1.00 r= 1.179. pounds water to be evaporated. 

12.00 

1.179 X 966 = 1139, B. T. U. required. 

1139 — (2.179 X 65.45) 



1151.5 — 151.5 
condense using jacketed hot wells. 



996, pounds steam required to 



702 



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Calculation of Water, Steam, Fuel 703 

RELATION OF GAS, OIL AND COAL CONSUMPTION TO 
STEAM PRODUCTION. 

It is frequently desirable to know the relation between the fuel 
supply, and the steam produced in the boiler. Obviously this is 
open to wide fluctuations, the principal factors causing varia- 
tions being the kind of fuel; type of boiler used; quality of the 
water supply, and especially the efficiency of the methods of firing- 
employed. Due to these variables there is a wide gap in practice 
between the theoretical and the actual steam production. Table 
128 shows the above relations in the case of several of the most 
common American fuels, giving the steam produced at pressures 
of 5, 10 and 100 lbs. each respectively. Obviously the practical 
values given are only approximate, but yet they are accurate 
enough to serve as a practical guide. 

TO CALCULATE THE WATER, STEAM AND FUEL REQUIRED 
TO OPERATE A VACUUM PAN. 

It is frequently necessary to know, both for purposes of 
figuring costs, and for properly coordinating equipment capaci- 
ties, the water, steam and fuel necessary to condense milk into 
various products. The information given in this chapter is suf- 
ficient to permit anyone to arrive at these values quickly and 
easily. 

The following example will illustrate the principle of the cal- 
culation, and the same can be applied to any dairy product. 

Example : — "Wanted to condense 10000 lbs. skim-milk testing 
8.80 per cent total solids, into sweetened condensed skim-milk 
testing 28.00 per cent milk solids and 42.00 per cent sugar. 

Pan vapors 140^ F. Condenser water 120° F. Plain hot wells 
used. Water at 55° F. costing 6 cents per 1000 gallons. One U. S. 
gallon of water weighs 8.345 pounds. Hocking Valley bituminous 
coal used costing $6.50 per ton. Find quantity of water and 
coal required. 

Solution : — 
(a). 10000 X 8.80 — 880, pounds total solids in skim-milk. 

880 -f- .28 = 3143, pounds finished product possible to 
make. 



704 



The Vacuum Pan 

TABLE 128. 
Relation of Fuel Consumption to Steam Production. 



KIND OF FUEL 


Unit 


B. T. U. 


Pounds of steam produced by one unit 
of fuel starting with water at 32" F. 
and ending with steam at pressure 
indicated. 


Theo- 
retical 


Practical 




100 lbs. 


100 lbs. 


10 lbs. 


5 lbs. 


Natural gas, Ohio 


Cu. ft. 


1020' 


.86 


.65 


.67 


67 






Natural gas, Pa 


Cu. ft. 


1073' 


.91 


.68 


.70 


67 






Producer gas 


Cu. ft. 


145^ 


.12 


.09 


.09 


.09 


Coal gas 


Cu. ft. 


599' 


.51 


.38 


.39 


39 






Crude Oil, Calif 


Pound 
Sp.Gr. 0.966 


18667' 


15,75 


11.81 


12.11 


12.15 






Crude Oil, Texas 


Pound 
Sp.Gr. 0.924 


19060' 


16.09 


12.06 


12.37 


12.41 






Crude Oil, residium 


Pound 
Sp.Gr. 0.860 


19200' 


16.20 


12.15 


12.47 


12.50 


Anthracite, Northern field.. 


Pound 


13160' 


11.11 


7.78 


7.96 


8.01 


Semi-anthracite, 
Loyalsack. . 


Pound 


13920' 


11.75 


8.23 


8.44 


8.57 






Semi-bituminous, 

Pocahontas, W. Va 


Pound 


15070' 


12.70 


8.89 


9.12 


9.15 


Bituminous, Pittsburgh, Pa. 


Pound 


13410' 


11.31 


6.79 


6.97 


6.99 


Bituminous, 
Hocking Valley, Ohio... 


Pound 


12130' 


10.24 


6.14 


6.30 


6.32 


Lignites, Utah 


Pound 


11030' 


9.31 


5.12 


5.25 


5.27 



Operation 705 

3143 X -42 = 1320, pounds sugar required. 

10000 — (3143 — 1320) = 8177, pounds water removed 
from skim-milk. 
(b). 8177 X (15.2 -^ 8.345) = 14896, gallons water required. 

14.896 X .06 = $.89, cost of water, 
(e). 3143 X 3.398 = 10679, pounds of 5 lb. pressure steam re- 
quired. 

10679 ~ 6.32 = 1690, pounds, or .845 ton of Hocking 
Valley coal required. 
(d). .845 X $6.50 = $5.49, cost of coal. 

THE OPERATION OF THE VACUUM PAN. 

The operation of the vacuum pan and its practical application 
in the manufacture of various condensed milk products is con- 
sidered here. The discussion includes methods recommended in 
forewarming as well as other steps comprised in the complete con- 
densing operation. 

1. TO FOREWARM AND CONDENSE WHOLE MILK AND SKIM- 
MILK, BOTH PLAIN AND SUPERHEATED. 

(a). Forewarming or Heating in the Hot Wells. 

The forewarming operation is of very great importance as 
affecting the finished product. The influence of this operation 
is frequently neither properly understood nor properly appre- 
ciated in practice. 

In the manufacture of sterilized evaporated milk the fore- 
warming operation requires constant daily watching. The 
physical properties of the finished product are influenced very 
largely by the heat treatment given to the whole milk in the 
hot wells. At certain seasons too high a temperature in the hot 
wells raises the coagulating point of the finished product in the 
sterilizers, and thus makes it difficult, if not impossible, to pro- 
duce a product of the proper viscosity. Upon the other hand, in- 
sufficient forewarming lowers the coagulating point to such an 
extent as to make it difficult, if not impossible, to properly ster- 
ilize the finished product, on account of the excessive viscosity 
produced. The application of the above principles in practice, 
gives the processor one means for keeping the finished product 
under control. 



706 The Vacuum Pan 

The above principles are also applied in the manufacture of 
superheated products, where the aim is to obtain all the viscosity 
possible up to the point where the product still remains smooth, 
and free from lumps. 

The range of forewarming temperatures in the case of ster- 
ilized evaporated milk, either whole or skim, is from 140° F. to 
210° F. When as low a temperature as 140° F. is used, care 
must be taken to provide a safe sterilizing record. Under some 
conditions heating to 210° F., shutting off the steam, and heating 
again to 210° F. after a lapse of two to five minutes, may prove 
beneficial, but when this practice is followed, there is danger 
of producing a product too high in color. This latter trouble can 
be prevented to a considerable extent by reducing the sterilizing 
time and temperature to a minimum. 

The range of forewarming temperatures in the case of super- 
heated products is from 140° F. to 160° F. Obviously in these 
products the aim is to control the operations in such a way as 
to produce a high final viscosity. 

When using the plain type of hot well, the steam should be 
introduced into the milk at a pressure not to exceed ten pounds. 
Higher steam pressures are liable to cause chemical changes in 
the finished product. The steam line leading into the hot well 
should be fitted with an oil separator to remove any oil or water 
tliat might be contained in the steam. 

The forewarming should be so timed that the pan will be 
ready to receive the milk as soon as it has reached the desired 
temperature, in the hot wells. 

(b). To Start and Operate the Vacuum Pan. 

Before starting the operator should see that the pan is clean 
and thoroughly steamed ; that the water spray in the condenser 
is free from obstructions and that the stop valves upon the coils 
and jackets do not leak steam. 

The air vents are now all closed, and the vacuum pump is 
started up slowly, 'increasing the speed to 25 or 30 single strokes 
per minute. Open the water valve to the condenser as soon as 
15" to 20" of vacuum are obtained, and the milk in the hot wells 
has reached the desired temperature. The milk inlet valve is 
now opened wide. The milk always rises due to the air in the 



Operation 707 

same when first introduced into the pan. The operator must 
be upon the alert at this point and by means of the vacuum break 
introduce just enough air into the pan to hold the milk down 
to a safe limit. It will take only a few seconds for the pump to 
expel the air, and to obtain the proper vacuum. This result can 
be accomplished by the time the lower coils are covered with 
milk. In addition to introducing air in the pan to reduce the 
milk level, it may sometimes be necessar}^ to close off the milk 
suppl}^, and to shut off the steam for a few moments, until the 
proper vacuum has been reached. 

Sufficient milk should be in the pan, to cover one set of coils 
before turning on the steam. To arrive at the proper amount 
to introduce into the pan, it is suggested to fill one of the hot 
wells with water, to the level at which it is usually filled with 
milk. The water is now drawn into the pan until the lowest set of 
coils are all covered, and the new level upon the hot well is suit- 
ably marked for subsequent guidance. The above procedure will 
insure knowing just when the right amount of milk is in the pan 
to permit turning on the steam without danger of baking milk 
upon the coils. There is no other satisfactory way of doing this, 
owing to the foamy condition of the milk, in the pan. 

When turning on the steam, open the jacket valve first ; then 
the lowest coil, and the remaining coils after a lapse of three 
or four minutes. 

Whenever possible the condensing should be done with ex- 
haust steam. If insufficient exhaust steam is available to do all 
the condensing, the amount available should be utilized, and the 
shortage made up with live steam. Every well installed pan 
should be fitted to use either exhaust steam, live steam, or a com- 
bination of the two, when both are available. 

Simple devices are available for controlling automatically the 
pressure upon the steam header. 

The efficiency of exhaust steam for condensing purposes is due 
to its latent heat, thereby giving it a large number of available 
heat units, with a relatively low temperature. The higher the 
steam pressure the higher the temperature of the steam, without 
an increase in heat units proportional to the increase in tem- 
perature. These facts are of great moment in condensing milk. 
The higher the steam temperature, the greater the danger of the 



708 



The Vacuum Pan 



milk baking upon the coils, and also the greater the danger of the 
product being dark in color. It is not good practice to crowd 
the capacity of the pan by increasing the steam pressure inside 
the coils and jacket. The correct practice is to operate at moder- 
ate pressures, and within the ratings of the pan. 

Table 129 gives the available heat units and the temperature 
of exhaust steam, and of steam at various pressures. 

TABLE 129. 
Available Heat Units, Volume and Temperature of Steam at Various Pressures.- 



Pressure in 
pounds per 
square inch 
above sea 
level 


Temperature of 

steam 

Degrees F. 


Volume in 

cu. ft. 
occupied by 
one pound 


Normal heat 

expressed as 

B. T. U. in 

liquid form 32» F. 


Latent heat 

expressed as 

B. T. U. 


Total heat 

expressed as 

B. T. U. 

fromwaterat32''F. 




212.00 


26.36 


180.9 


965.7 


1146.6 






.3 


213.03 


26.14 


181.8 


965.1 


1146.9 


2.0 


219.00 


23.65 


187.8 


960.9 


1148.7 


3.5 


223.47 


21.78 


191.9 


957.8 


1149.7 


5. 


227.05 


19.54 


196.0 


954.0 


1150.0 


10. 


239.32 


15.90 


208.4 


945.5 


1153.9 


25. 


266.65 


10.29 


235.9 


926.3 


1162.2 


40. 


286.53 


7.66 


255.9 


912.8 


1168.7 


100. 


337.66 


3.76 


398.5 


876.1 


1184.6 



It is evident from the data contained in the above table that 
with a pan of proper design. — that is, one that contains the 
necessary heating surface, and amply large openings into the 
coils and jacket, every advantage is gained by using low pressure 
steam. Five pounds should be the maximum under proper oper- 
ating conditions. 

The same pressure should be carried upon the coils and the 
jacket. The steam in the jacket causes the milk to "kick up". 
That in the coils causes it to "roll", and to drop back towards 
the center of the pan. 



Operation 709 

The level of the boiling milk should be not more than half 
way up the waist. The milk intake cock should be so adjusted 
that the milk will condense about as fast as it is drawn into 
the pan. 

The milk should test near the end of the run, and before 
lowering the steam pressure, from 5 to 10 points lower upon the 
hydrometer than the striking point desired. Also all the milk 
from the hot wells should be in the pan before turning off the 
steam. This will help to obtain a more correct hydrometer 
reading. 

The best pan temperature to maintain upon plain condensed 
milk is from 122° to 140° F. The best method is to maintain the 
temperature near 140° F., throughout the run until the finishing 
point is nearl.y reached. At this point the temperature can be 
dropped to about 120° F. by reducing the steam pressure. This 
will make for greater accuracy in arriving at the end point. Be- 
low 122° F. the evaporation becomes too slow, while above 140° F. 
the evaporation also becomes slower, and the higher temperature 
tends to produce a dark colored product. While the evaporation 
is proceeding rapidly, the temperature of the water vapors in the 
pan will be the same as that of the milk itself. Near the end of 
the run there may be a considerable difference between the two, so 
that the temperature of the milk itself should be the proper guide 
for the operator, especially when striking the batch. 

If the pan temperature should drop under the point at which 
it is desired to be carried, in order to raise it, the water supply 
should be decreased, and sometimes the steam supply can be 
increased to advantage. A drop in pan temperature as above 
may be due to a decrease in the steam supply, to water being 
carried over from the boilers, or to the condensation being im- 
properly removed from the coils and jacket. 

If the pan temperature should rise above 140° F., the water 
supply should be increased, and the steam pressure decreased. 
A condition of this kind may be caused by air leaks into the pan, 
increase in the steam pressure, without any corresponding in- 
crease in the water supply to the pan, or to the spray pipe in the 
condenser becoming clogged. 



/'lO The Vacuum Pan 

(c). To Strike the Batch. 

The reader is referred to Chapter XI for detailed information 
as to the specific gravity of evaporated milk under different con- 
ditions, and as to suggestions for striking the batch. This is an 
operation that requires both skill and care. The steam should 
be kept upon the coils and jacket as long as possible, in order not 
to reduce the capacity of the pan. And upon the other hand, 
it should not be kept on long enough to over-condense the milk. 

Usually the time method can be used to good advantage to 
aid in arriving at the striking point. Under this method the 
operator ascertains by experiment just how long it takes to in- 
crease the hydrometer reading one-tenth degree after the milk 
from the batch is all in the pan, and while the full steam pressure 
remains upon the coils and the jacket at a certain pan tem- 
perature. 

Example : — Test desired 6.35 degrees Baume at 140 ' P. Test 
increases at rate of .lO"" B. for every minute. 

Preliminary test found to be 6.05° Baume at l^O'' F. 

Solution : 6.35 — 6.05 =: .30, degrees short. 
.30 -f- .10 = 3, minutes additional necessary to operate pan be- 
fore turning off the steam. 

(d). To Finish the Pan Batch. 

The first step after reaching the striking point is to close off 
the steam valves. If plenty of cold water is available, leave the 
water valve to the condenser open, with the vacuum on, for two 
or three minutes. This will cool the milk in the pan to about 
100° F., and thus it will assist greatly with the subsequent cooling 
of the batch. The vacuum break is now opened ; the water valve 
to the condenser is closed, and the vacuum pump is shut down. 
Do not open the draw off valve until the vacuum has been reduced 
to two or three inches. If opened sooner, the manhole cover may 
be blown off, or some milk may be lost. 

The proper handling of the milk immediately after it leaves 
the pan, is of prime importance. Equipment should be on hand 
to cool the product from the pan rapidly and efficiently^ 

(e). To Superheat the Batch. 

Superheating both condensed, whole and skim-railk is an old 
established trade custom. Possibly with but few exceptional 



Finishing the Batch 711 

cases there is but little merit or advantage to this practice, in so 
far as it may improve the quality of the product. The super- 
heating coagulates part of both the albumin and the casein, thus 
greatly increasing the viscosity without increasing the total solids 
in the product. It frequently happens that superheating may 
give an entirely false impression as to the total solids content of 
the product. The modern tendency is to buy milk products upon 
the basis of their fat and total solids contents, together with the 
necessary specifications regarding their essential physical pro- 
perties. The method of superheating given herewith is inserted 
for the benefit of those called upon to furnish such products. 

As already noted, when making superheated products, the 
fluid milk in the hot wells, should not be heated to exceed 160° F. 

Condense the milk in the pan as described above. Strike the 
batch about two degrees Baume higher then necessary to pro- 
duce the total solids desired. The steam condensed into the milk 
in superheating should not dilute the milk under the standard 
desired. Keep the temperature up to 140° F. at the time of 
striking. The steam from the coils and the jacket is now turned 
off, and the vacuum pump is shut down, but the vacuum is allow- 
ed to remain in the pan. The superheating steam valve is now 
opened wide, using full boiler pressure up to 100 pounds. Lower 
pressures will unduly prolong this operation. Obviously as the 
temperature of the milk rises, the 'vacuum in the pan decreases. 
The superheating is continued until the milk reaches a temper- 
ature of 180° F., and the vacuum has reached about 13". The 
end temperature has to be varied depending upon the concentra- 
tion, and the condition of the milk. Obviously milk of higher 
concentration will reach the desired viscosity in superheating at 
a lower temperature than milk of lower concentration. Like- 
wise milk of high acid content will superheat much more rapidly, 
and at lower temperatures, than milk of low acid content, or 
than milk with low coagulating point due to causes other than 
the acidity of the same. Likewise milk with high coagulating 
point, has to be superheated at times, as high as 190° F., before 
obtaining the desired viscosity. 

The end point in superheating is found by sampling at the 
striking cup. If the superheating is carried too far there is 
danger of "cracking" the product. That is, of coagulating the 



712 The Vacuum Pan 

casein in lumps, so that the product loses its smooth, velvety ap- 
pearance. This can be avoided by care and experience, and if 
by chance the superheating has been carried too far, the lumpy 
condition thus produced can be overcome by running- the product 
through the homogenizer. But of course the preventative is bet- 
ter than the cure. The superheating operation consumes con- 
siderable time, requiring about 30 minutes for about 5000 pounds 
of finished product, upon the proper size of pan. 

When the desired viscosity has been obtained, the super- 
heating valve is closed ; the vacuum pump is started ; and the 
water is turned on in the condenser, very slowly at first. The 
batch is now cooled in the pan to at least 140° F., — preferably 
to 120° F. before dropping it out of the pan. 

On account of its viscous condition, superheated condensed 
milk is one of the most difficult of all dairy products to cool. 
The proper cooling of this product requires the use of equipment 
well designed for this work, and the use of cooling mediums of 
low temperature. 

The product should be tested for fat and total solids while the 
batch is being cooled, and the materials necessary to use for 
standardizing should subsequently be added, cooled and mixed 
with the balance of the batch. 

(f). Precautions in Pan Operation. 

The efficient operation of a vacuum pan is influenced by sev- 
eral conditions that should be well understood by every pan op- 
erator. 

The following are the most important of these conditions : 

Condition of Heating- Surfaces. Two conditions may exist 
to decrease the efficiency of the heating surfaces. 

The outside of the coils and the jacket may become coated 
Math coagulated milk. This condition is caused by the use of 
too high steam pressure ; by the presence of water inside of the 
coils ; by condensing milk too high in acidity ; Jjy turning on 
steam before the heating surfaces are all covered ; by condensing 
too many batches before cleaning the pan, and by careless, im- 
proper cleaning of the pan. The layer of milk acts as an insu- 
lator, and greatly hinders the transmission of the heat from the 
steam to the milk. Under good operation the above difficulties 
can be readily eliminated. 



Air Leaks 



713 



The inside of the coils and the jacket may become partly or 
completely filled with water, due to improper methods of trap- 
ping off the condensation; improper coil or jacket construction, 
or the use of steam containing much water condensed into it. 
The coils should be designed to completely and rapidly carry off 
the Avater as soon as it forms. The water also acts as an insu- 
lator, and prevents the transmission of the heat from the steam 
to the milk. 

The tAvo conditions described above are graphically illustrated 
under Fig. 164. These conditions greatly reduce the capacity 
of vacuum pans, and to a lesser extent cause the use of increased 
amounts of both steam and water. 



WALL OF COPPLR TUBE 

CONDLNSLD STLAM 





WALL OF COPPLR TUBL 
CRUST OF MILK SOLIDS 



Fig-. 164. Factors That Influence Heat Transmission. 



Air Leaks Into Pan. If any considerable amount of air should 
get into the pan, while under operation, the milk intake valve 
should be immediately shut off. As soon as the air enters the 
pan, the milk Avill cease boiling, and it will appear motionless 
upon the bottom of the pan. Just as soon as the vacuum pump 
begins again to remove the air and to form vacuum, the milk 
will immediately get very wild and foamy. Great care must be 



714 The Vacuum Pan 

exercised by the operator at this moment. Just enough air 
should be introduced through the vacuum break to keep down the 
milk in the pan until the proper vacuum has been regained. The 
steam can be then gradually turned on the coils and jacket. The 
steam should be shut ofif from the coils and the jacket just as 
soon as the above condition is discovered. If this is not done, 
the heating surfaces will soon become coated with milk. 

Large air leaks into the pan are caused principally by the 
water supply tank becoming dry ; to the accidental breaking of 
an eye glass ; to the emptying of a hot well without closing the 
milk intake valve; or when jacketed hot wells are used, to air 
being drawn in through the "whirlpool". This last named con- 
dition can be simply and easily prevented by a small device used 
for that purpose. 




Pig-. 165. Device for Breaking 'Whirlpool in Jacketed Hot Well. To Be 
Inserted in Discharge Opening. 

Influence of Bicarbonate of soda. 

If bicarbonate of soda is added to the last portions of milk 
remaining in the hot wells, and just before drawing into the 
pan, this will cause the milk in the pan to become very wild and 
foamy, due to the excessive amount of carbon dioxide generated. 
Under these conditions great care must be exercised by the op- 
erator, and the milk should be drawn into the pan only as fast 
as the vacuum pump can expel the gas. 

"When necessary to use bicarbonate of soda, this should be 
added to the milk in the hot wells before any steam has been 
introduced into the milk. Under these conditions a large part 
of the gas will be eliminated as the milk is being heated, and 
before it enters the pan. 

Cleaning the Pan. After the day's run has been completed 
draw enough water into the pan to submerge all the coils. Allow 
to stand for at least 15 minutes, or if time is available, as much 
as several hours. Empty and clean the pan, taking care that the 
milk is completely removed. 



Losses 715 

The cleaning of vacuum pans and hot wells can be greatly 
facilitated by the use of caustic alkali, properly applied. The 
use of caustic alkali for this purpose originated in Europe, and 
full report upon the subject was made by Dr. Hamilton." 
In order to obtain proper results it is necessary to use the right 
concentration of the alkali, and to apply it hot. Devices are 
available for accomplishing this result simply and efficiently. 

The merit of this method is owing to the solubility of coagu- 
lated casein and albumin in even very dilute solutions of caustic 
alkali. Soon after applying the alkali, it becomes possible to re- 
move the coagulated products, which under the action of the 
alkali, have been converted into slimy substances, that are easily 
removed from the heating surfaces. 

In using caustic alkali good judgment must be exercised. It 
should be applied only a few minutes before the cleaning of the 
pan is started, and it should be applied only to the surfaces con- 
taining coagulated milk. Under no condition should the alkali 
be added for any considerable time before cleaning the pan. 
These precautions are necessary owing to the solubility of tin 
in caustic alkali, causing decomposition of the solder, and thus 
weakening the seams of the pan. 

The final step in cleaning a pan is to rinse the pan freely with 
w^ater, and then in turn to follow up the rinsing with a thorough 
steaming. The pan will thus soon become thoroughly dry, with- 
out any verdigris forming in it. The rinsing and steaming 
should be repeated before starting the pan, the following morn- 
ing. 

Entrainment Losses. By this is meant the solid portions that 
are mechanically carried over into the condenser. These losses 
are caused by improper pan design ; by carrying the milk too 
high in the waist of the pan; by careless operation, or by large 
air leaks. The same may be reduced to small proportions by 
careful operation. A good index of entrainment losses is the 
color of the water discharging from the vacuum pump. Even 
slight coloration is an indication of milk solids being carried over 
into the condenser. 

There is also a small loss due to stickage, which is caused by 
conditions already named, all of which can be very largely pre- 
vented, under careful operation. 



716 The Vacuum Pan 

(2). TO FOREWARM AND CONDENSE BOTH SWEETENED 

CONDENSED WHOLE MILK AND SWEETENED 

CONDENSED SKIM-MILK. 

(a). Forewarming or Heating in the Hot Wells. 

The forewarming of the fluid milk in making the above pro- 
ducts is subject to many differences in practice. In some cases 
the heating is carried only to 140° to 160° F. This method has 
the advantage of giving the finished product a minimum amount 
of color. It has the disadvantage of not reducing the bacterial 
flora as much as is usually desirable. It may have the further 
disadvantage of not dissolving the added sugar, as completely as 
it should be. The more common and the preferable practice is 
to heat the fluid product up to 200° to 210° F. If the heating 
is done carefully, a finished product can be produced that i§ of 
very satisfactory color, and at the same time the disadvantages 
of the first method named can thus be largely overcome. 

It is recommended that no sugar be added to the first hot 
well in making up a batch. The total sugar making up 'a batch 
can be divided between the remaining hot wells, except that the 
final addition of sugar necessary for standardizing the batch can 
be added to the last hot well. 

Both the plain and jacketed type of hot wells are used in 
making sweetened condensed milk. The operating advantages 
are in favor of the jacketed type, as in the case of unsweetened 
condensed milk. The disadvantage is in the first cost of the 
latter. 

(b). The Operation of the Vacuum Pan Upon Sweetened 
condensed milk. 

The operation of a vacuum pan upon sweetened condensed 
milk, is in all essential respects, the same as in the case of un- 
sweetened products. The principal difference is in the con- 
centration of the two products. 

(c). Striking the Batch, in the Case of Sweetened Condensed 
milk. 

Chapter XII contains detailed information as to the specific 
gravity of different kinds of sweetened condensed milk. Several 
methods for ascertaining the end point, and which depend for 
their success upon the judgment of the operator, are sometimes 



Sweetened Condensed Milk 717 

used, but none of these are reliable, and the same should be de- 
pended upon only as an aid, and not as a means. The most 
satisfactory method devised up to this time, is by means of hydro- 
meters, suitably graduated and properly used. 

The striking operation requires skill, speed and care. A vacu- 
um pan seven feet in diameter removes water at the rate of 
about 100 pounds per minute. Near the end of the run, the re- 
moval of this amount of water per minute in a batch of about 
15000 pounds of whole milk, would increase the total solids at 
the rate of one per cent per minute. 

(d). To Finish the Pan Batch when Making Sweetened Con 
densed Milk. 

Proceed as in the case of unsweetened condensed milk. The 
practice of cooling the product in the pan may be advantageously 
followed, but the temperature is seldom lowered here, under 
120° F. 

Sweetened condensed milk should not be allowed to remain 
in the pan under heat after the batch is done. This will super- 
heat and thicken the product, and in many cases render it un- 
salable. The method of handling the condensed product, after 
it leaves the pan, is fully described in Chapter XII. 

The precautions in pan operation are the same as in the case 
of unsweetened condensed milk, and the operator should thor- 
oughly familiarize himself with every condition requisite for suc- 
cessful operation. 

(e). To Forewarm and Condense Liquid Dairy Products, 
Other Than Unsweetened and Sweetened Condensed Milk 

The vacuum pan can be used to condense any liquid dairy 
product, as well as unsweetened and sweetened condensed milk, 
many of which are of great commercial and economical impor- 
tance. These products can be reduced to a liquid, semi-liquid, or 
solid state. 

Ice cream mix is the most recent product to be added to the 
list, and the process for making this in the vacuum pan is sub- 
ject to patents now pending by one of the authors'' and one of his 
brothers By this process a superior quality of product can be 
obtained, besides the numerous economic advantages. The tem- 
peratures during no part of the operation are allowed to exceed 



718 The Vacuum Pan 

140° F., so that the natural flavors are fully retained. The 
temperature used in condensing the mix is the same as that used 
in pasteurizing, therefore the pasteurizing and condensing are 
combined in one operation. The principles involved are the same 
as in the case of other dairy products. The whole milk, butter 
or cream, sugar and the gelatin are all added in the hot wells, 
and condensed together in the vacuum pan. The striking point 
varies obviously with the composition of the product being 
manufactured. The specific gravity of different ice cream mixes 
is given in Chapter XIII. 

Condensed buttermilk is a product of growing commercial 
importance. It is condensed to a semi-paste condition. The 
heavy viscosity is due both to its concentration, and to slightly 
superheating before drawing it out of the pan. The usual 
method is to heat the buttermilk in the hot wells at 145° F., to 
condense at the pan temperatures usually used in the case of 
unsweetened condensed milk products, and finally to superheat 
in the pan to 160° F. It is run while hot, directly into shipping 
barrels, and it is cooled after being barreled. The specific grav- 
ity of this product at various concentrations is given in Chap- 
ter XIV. 

Malted milk is an American product of world wide distribu- 
tion and of considerable commercial importance. It is finished 
in a special pan wherein it is reduced to a dry state, before 
removing it from the pan. 

Whey used to make milk sugar can frequently be condensed 
to a semi-liquid or dry state before shipping to a central refining 
plant. The advantage is in the superiority of the product, and 
the saving in transportation charges. 

REFERENCES. 

1 Hunziker, O. F., La Grange, 111. "Condensed Milk and Milk Powder," 

p. 87, 3rd edition. 

2 Snow & Leland. "The Steam Engine," 1908, p. 88. 

3 Poole. "The Calorific Power of Fuels." 

* Gill, A. H. "E'ngine Room Chemistry," p. 72. 
" Report, U. S. "Liquid Fuel," Board 1904. 

« Babcock and Wilcox Co. "Steam." 
'Hamilton, Molkerie-Zeitung, No. 16, 1901. 

* Mojonnier. T. 



CHAPTER XIX 
EVAPORATED MILK 

ITS STERILIZATION AND PHYSICAL AND CHEMICAL CONTROL. 

In plants manufacturing evaporated milk, the proper steriliza- 
tion of the product is one of the most important of the operations. 
Conditions that affect sterilizing time and temperature vary great- 
ly over the course of the year, and frequently from day to day. 
Unless the factors that affect sterilization are properly under- 
stood and in turn applied in daily practice, the product will be 
irregular in its physical properties or it will be both irregular and 
develop spoilage after manufacture. 

The ideal aimed at in this chapter is to recommend methods 
and processes for sterilizing evaporated milk whereby the phys- 
ical properties of this product, namely the viscosity, flavor and 
color, can be kept uniform at all times and under all conditions ; 
and at the same time insure proper sterilization so that spoilage 
Mall be entirely eliminated. To insure these results operations 
going back to the farms need to be imderstood and closely 
watched from day to day, and the knowledge thus gained ap- 
plied in daily practice. The two-fold purpose of sterilization 
should be kept in mind at all times. First, to insure the keeping 
qualities of the product ; and second to impart to the product the 
physical properties referred to above that are demanded by trade, 
custom, or personal preference. 

The Choice of Sterilizer. — Several makes of sterilizers are upon 
the market, most of which if properly operated can be used 
with success. These are offered in a large range of sizes to suit 
all ranges of production. Two common types of sterilizers that 
are extensively used are illustrated under Figs. 166 and 167. 
Many of the problems involved in the operation of the sterilizers 
are purely mechanical, and must be determined by local con- 
ditions. Other phases of the subject will be discussed in this 
chapter. 

[719 1 



720 Evaporated Milk 

The Sterilizing Process. — The time and temperatures used in 
sterilizing, and the mechanical manipulations of the sterilizers 
during the sterilizing process are subject to many needless 
fluctuations in practice. Space will not be consumed to discuss 




Tig. 166. Fort Wayne Sterilizer. 

Courtesy The Engineering Co. 

the relative merits of these different methods, but the discussion 
will concern only the process that the authors know from wide 
experience to give satisfactor.y results at all times. Furthermore 
the modern tendency is to standardize the sterilizing process 
not only as between the plants of the same manufacturer, but in 
a larger sense, as between the plants of different manufacturers. 
The process in brief is as follows : 

Coming-up time. — A minimum of 15 minutes, and a maxi- 
mum of 20 minutes should be taken to raise the temperature in 
the sterilizer from room temperature, to the temperature at 
which the milk is to be sterilized. This is commonly known as 



Sterilization 



721 



the "coming-iip time." Where water is used in the sterilizers 
during the processing uniform results may be obtained with 15 
minutes coming up time. When live steam is used, the best 
results are obtained when 20 minutes elapse. The relation be- 
tween minutes in coming up and the temperature in the sterilizer 
is indicated both for the 15 and 20 minute intervals in Table 130. 




Pig-. 167. BerUn Sterilizer. 

Courtesy Berlin Canning Machinery Works. 



As indicated in the table the temperature should be at 190° F. 
at the end of 5 minutes when 15 minutes is the coming up time 
used, and at the end of 10 minutes when 20 minutes is used. 
The rate of increase is more rapid between the initial tempera- 
ture and 170° F., than it is from 170° F. to 240° F. During the 
last 10 minutes of the coming up time the increase should be at 
the rate of 5° F. for every minute. 

Influence of Speed of Sterilizer Reel. — The speed at which 
the sterilizer reel is operated has a very important bearing upon 
the sterilizing operation. The faster the reel is operated the 
more rapidly the milk will heat inside of the can, and also the 
more rapidly it will cool at the end of the run. Too rapid reeling 
tends to destroy the viscosity, and to produce a grainy finished 
product. Too slow reeling produces a clabbery product — one 
that is sterilized with difficulty, and that cools very slowly. 

The proper speed of the reel is from six to ten turns per 
minute depending upon the diameter of the sterilizer. A sterilizer 
of 96 case capacity produces the best results at six turns per 
minute. A 30 case sterilizer at ten turns per minute. 



722 



Evaporated Milk 



TABLE 130. 
Relation Between Temperature and Time When Coming Up in Sterilizers. 



Minutes after 

turning on 

steam. 


Temperature in 

sterilizer at 

corresponding 

minute. Degrees F. 

70 


Minutes after 

turning on 

steam. 


Temperature in 

sterilizer at 

corresponding 

minute. Degrees F. 


1 


6 11 


195 


1 2 


90 


7 12 


200 


3 


110 


8 13 


205 


2 4 


130 


9 14 


210 


5 


150 


10 15 


215 


3 6 


170 


11 16 


220 


7 


175 


12 17 


225 


4 8 


180 


13 18 


230 


9 


185 


14 19 


235 


5 10 


190 


15 20 


240 



The Addition of Water to the Sterilizers. — Adding water to 
the sterilizers before turning on the steam usually helps to pro- 
duce more uniform sterilization, but the practice is not a universal 
one. The proper spacing of the cans in the trays and in the 
crates is a factor that influences uniformity of sterilization. The 
spacing and the placing of the cans should be such as to facilitate 
the transmission of the heat equally to all of the cans in the batch, 

When water is added just enough should be used to cover all 
of the cans in one position of the reel. Savings in coal can be 
affected by storing the hot water between the sterilizer runs in a 
suitable tank, so placed that the water will run by gravity back 
into the sterilizer at the beginning of the succeeding run. The 
above points are illustrated under Fig. 168. 

Holding" temperature. — The minimum temperature recom- 
mended is 240° F., and the maximum 245° F., with the proper 
holding time. 

Holding time. The holding time never should be less than 
15 minutes with the temperature never under 240° F, 



Sterilization 



723 




TO SLNNLR-^ '^VALVE TO TANK - 
Pigr. 168. Sterilizer Arrangrement When Using Hot Water in Sterilizing'. 



Cooling time. — From 15 to 20 minutes, depending upon the 
temperature of the water. The cooling should be continued until 
the temperature of the milk throughout the batch is between 70 
and 80° F., or about room temperature. If all the factors affect- 
ing sterilization are properly controlled the sterilizing process 
can be kept between the following limits at all times : — 



Coming up time 
Holding temperature 
Holding time 
Cooling time 



mnnmum 
maximum 



yi5 minutes minimum 
"4 20 minutes maximum 

(240° F. 
\245° F. 

1 15 minutes minimum 
I 20 minutes maximum 

!15 minutes minimum 
20 miiiUtes maximum 



724 



Evaporated Milk 



The sterilizing process, as recommended above, from the time 
the steam is introduced until the cooling of the batch has been 
completed is shown in the graph represented over Fig. 169. 



s 



15 ZO 25 
lO 15 



30 35 40 45 SO 



TIMEINMINUTE.5. 



Tig. 169. The Relation Between Coming- TJp Time, Holding Temperature, 
Holding- Time, and Cooling- Time in Sterilizing Evaporated Milk. 



Controlling Equipment 725 

MOJONNIER EVAPORATED MILK CONTROLLER. 

This apparatus was designed especially to provide a means for 
controlling all the factors that atfect the sterilization of evapo- 
rated milk. It is illustrated under Fig. 170. To 0. W. Mojonnier 
was granted U. S. patents covering the fundamental processes 
underlying its operation. Its application will be described further 
in this chapter. 




Fig-. 170. Mojonnier Evaporated Milk ControUer. 

Factors That Influence the Heat Coagulation of Milk. — The 

starting point of a good finished product is a good supply of fresh 
milk. The acid content should be kept as low as possible at all 
times. At certain seasons the processing is very difficult even 



726 



Evaporated Milk 



with a milk supply of low acid content. This is due to the sev- 
eral factors that influence the coagulating point of casein and 
albumin as follows : 

(a) . Effect of acid content upon the coagulating point of milk. 
— The ease with which sour milk curdles when heated is a fact of 
common knowledge. Advantage of this fact is taken in the manu- 
facture of cottage cheese. The difficulties encountered in steril- 
izing evaporated milk as a rule increase as the content of titra- 
table acidity increases. This is particularly true if the titratable 
acidity is due in part, at least, to the decomposition of the milk 
sugar into lactic acid by bacterial growth. 

It has been proved by several investigators (among whom can 
be mentioned Rice,^ and Sommer and Hart-) that the percentage 
of titratable acidity in milk as drawn from the cow, varies be- 
tween rather wide limits. Sommer and Hart found no definite 
relation between the titratable acidity in freshly drawn milk, and 
the heat coagulation of the same. The summary of their inter- 
esting experiments are contained in Table 131. 

TABLE 131. 

Summary of Results. Sommer and Hart Upon Relation of Titratable Acidity 

and Heat Coagulation, 





No. 

of 

cows 

tested 


Titratable acidity 
in per cent. 


No. samples 
that tested 

over 
.18 per cent 


No. samples 
testing over 
. 18 per cent 

that coagu- 
lated within 

20 minutes 


No. samples 
that tested 

under 
.18 per cent 


No. samples 
testing under 
.18 per cent 


Date 


Min. 
imum 


Max- 
imum 


Aver- 
age 


that coagu- 
lated within 
20 minutes 


May 8, 1919 


26 


.120 


.257 


.185 


15 


5 


11 


6 


May 10, 1919 


30 


.131 


.241 


.196 


14 


7 


16 


7 


May 16. 1919 


30 


.102 


.203 


.167 


16 


11 


14 


6 


Total 


86 






.178 


45 


23 


41 


19 



In the above experiment 51.2 per cent of the samples testing 
above .18 per cent of acid coagulated under 20 minutes when 
heated in a sealed glass tube held in a xylene vapor bath at a 
temperature of 136° C. Likewise 46.4 per cent of the total sam- 
ples testing under .18 per cent of acid, coagulated in less than 20 
minutes. 

These results show that when an acidity test is depended upon 
entirely when grading milk that is to be used for making evapo- 
rated milk, an entirely false criterion of its value may be ob- 
tained. 



Coagulation Control 727 

The quantity of acid required to influence the coagulating 
point of milk is too small to permit of its control by titration 
methods. High titratable acidity in fresh milk cannot be de- 
tected by the senses of taste or of smell. To a trained person 
even small quantities of acid produced by bacterial growth can 
be readily detected by the senses of taste or of smell or by both. 
The most concealing factor to the sense of smell is the tempera- 
ture of the milk — the colder the milk the more difficult it be- 
comes to detect any acid development in the milk. 

In practice unquestionably the best method of grading milk 
at the factory's intake is by means of the senses of taste and 
smell, both intelligently applied by a trained person. This in 
turn should be supplemented by careful observation of the be- 
havior of the milk accepted, under the processes to which it is 
to be subjected. Any indication of milk taken which reacts un- 
favorably under heat, should lead at once to increased vigilance 
at the intake. 

If it should be desired to determine the coagulability of the 
milk from individual cows, cans or herds this can be done by 
using the method devised by Sommer and Hart, or by means of 
one or more of the methods given in Chapter XVII of this book. 
A means is thus available for tracing trouble to the original 
source. 

The acid content of the fresh product increases in direct pro- 
portion to the degree of condensation. Obviously the higher the 
degree of condensation the greater Avill be the acid content of 
the evaporated milk before sterilizing the same. 

Mclnerney ■'' made a careful study of the influence of the acid 
content upon the coagulating point of milk. To 100 cc. of milk 
there Avas added sufficient N/10 lactic acid to build up the total 
acidity to the test desired. "The mixture of milk and acid was 
then heated in the steam bath until the milk coagulated, and the 
temperature was noted. The amount of acid required to co- 
agulate the milk decreased as the temperature increased from 70 
to 180° F." 

The composition of the milk studied is not reported. Typical 
results covering these kinds of milk are given in Table 132. 



728 



Evaporated Milk 



TABLE 132. 
Influence of Acid Content Upon the Coagulating Temperature of Milk. 



Skim-milk testing 


Whole milk testing 


Pasteurized whole milk 


.145 per cent acid 


.140 per 


cent acid 


testing .150 per cent acid 


Total 


Coagulating T 


otal 


Coagulating 


Total 


Coagvilating 


acid 


temperature .i 


cid 


temperature 


acid 


temperature 


Per cent 


°F Pe 


r cent 


op 


Per cent 


op 


.580 


70 


530 


73 


.560 


66 


.480 


104 


480 


87 


.500 


85 


.430 


145 


440 


110 


.480 


83 


.390 


150 


400 


110 


.450 


95 


.340 


155 


350 


147 


.410 


96 


.280 


170 


310 


162 


.400 


104 


.250 


185 


270 


175 


.390 
.370 
.360 
.320 


110 
140 
150 
160 



"These experiments show that milk containing 0.57 per cent 
acid (in terms of lactic acid) will, on the average, precipitate at 
a temperature between 60° to 65° F. Milk containing 0.50 per 
cent acid will curdle at 75° to 80° F., 0.40 per cent at 100° to 110° 
F., 0.35 per cent at about 150° F. and 0.25 per cent acid in milk 
will not cause coagulation until heated to 180° F. As shown in 
Table 132 the small drop in acidity between 0.40 to 0.35 per cent 
makes a greater range of temperature than between any other 
two points of acidity studied. As shown in the experiments, a 
decrease of 0.05 per cent acid at this particular stage requires 
nearly a 50° F. range in temperature to produce coagulation as 
0.40 per cent acid in milk will curdle at about 100° F. Avhile 0.35 
per cent acid in milk will not produce curdling until heated to at 
least 150° F." 

(b). Influence of the nitrogenous constituents upon the coagu- 
lating point of milk. — From the standpoint of the manufacture of 
evaporated milk all of the nitrogenous constituents of milk are of 
interest and divide themselves into three separate and distinct 
substances or groups of substances, as follows: (1) Casein which 
coagulates in the cold in the presence of acid only. It also co- 
agulates under pressure at temperatures above the boiling point 
of water, in either alkaline, neutral, or slightly acid mediums. (2). 
Albumin which coagulates in part under heat in normal milk, and 
completely in an acid medium. (3) Other nitrogenous constitu- 
ents which are not precipitated either by acids or by heat. This 
group probably includes quite a number of different chemical en- 



Coagulation Control, 



729 



titles. All of the above substances dissolve in weak alkaline solu- 
tions, after having been coagulated. 

In processing evaporated milk the casein and albumin are the 
products of the greatest importance. These two substances vary 
in milk both in the total percentages of the two present, as well as 
in their relative percentages. 

Albumin predominates especially in colostrum milk, which ac- 
counts for the ease with which such milk is curdled by heat. 
Hunziker * reports the composition of the nitrogenous constituents 
of the milk from three cows at monthly intervals during an entire 
lactation period, as shown in Table 133. 

The influence of egg albumin upon the coagulating point of 
evaporated milk is illustrated by the following experiment. To 
one six ounce can of unsterilized evaporated milk there was added 
one cc. and to a second can four cc. of fresh egg albumin. After 
sterilizing under standard time and temperature along with a 
control can to which nothing had been added, both were com- 
pared with the blank can. The can to which one cc. of the egg 
albumin had been added showed a considerable increase in vis- 
cosity, and tliat to whicli five cc. had been added showed a very 
large increase in viscosity over that of the blank can. This in- 
dicated a large decrease in the coagulating point due to the added 
egg albumin. 

TABLE 133. 

Effect of Period of Lactation on the Percentages of Albumin, Casein and 
Total Proteid in the Milk of Three Cows. 



feriod of 
Lactation 


Albu- 
min 


Cow No. 1 






Cow No. 2 


Cow No. 3 




Case- 
in 


Total 
Proteids 


Albu- 
min 


Case- 
in 


Total 
Proteids 


Albu- 
min 


Case- 
in 


Total 
Proteids 


First 14 milkings 


.98 
.57 
.53 
.52 
.56 
.55 
.53 
.86 
.75 
.73 
.77 
.91 


3.18 
2.55 
2.27 
2.54 
2.51 
2.62 
2.65 
2.62 
2.79 
2.84 
3.02 
3.08 


4.16 
3.12 
2.80 
3.06 
3.07 
3.17 
3.18 
3.48 
3.54 
3.57 
2.79 
3.99 


1.59 
.55 
.47 
.48 
.50 
.48 
.54 
.76 
.60 
.56 
.59 
.61 


3.81 
2.47 
2.37 
2.28 
2.36 
2.26 
2.30 
2.50 
2.66 
2.73 
2.73 
2.88 


5.40 
3.02 
2.84 
2.76 
2.86 
2.74 
2.84 
3.26 
3.26 
3.29 
3.32 
3.49 


1.72 
.58 
.51 
.55 
.60 
.60 
.73 
.62 
.64 
.72 
.82 


4.46 
2.88 
3.06 
3.25 
3.05 
3.05 
2.96 
2.99 
2.94 
3.30 
3.39 


6.18 
3.40 


2nd month 


3.57 




3.80 




3.65 


5th month 


3.65 


6th month 


3.69 


7th month 


3.61 


8th month 


3.58 


9th month 


4.02 


10th month 


4.21 


lltn month 









It becomes obvious from the above facts that milk high in 
colostrum when made into evaporated milk will very likely have 



730 



Evaporated Milk 



a low coagulating point, and therefore it will be very difficult 
to sterilize properly. Sterilizing difficulties due to the above 
causes are of comparatively rare occurence where the proper 
control is maintained over the milk supply. In the mixed milk 
from many herds the variations in the percentages of the nitro- 
genous constituents are relatively small, especially where colo- 
strum milk is completely rejected. 

(c). Influence of the mineral constituents. — It has been long 
known that the addition of certain mineral salts, and other sub- 
stances, exert a marked influence upon the coagulating point of 
evaporated milk. In some cases the coagulating point is lowered. 
In others it is increased. 

One of the authors'^ by careful experiment determined the 
influence of the addition of various substances upon the coagu- 
lating point of evaporated milk. These substances were added 
in known amounts to six ounce cans of evaporated milk before 
sterilizing. The influence of the added substance was noted 
immediately after sterilizing. The results are given in Table 134. 



TABLE 134. 
Influence of Added Salts on the Coagulating Point of Evaporated Milk. 



Name of substance 

added to 

evaporated milk 

before sterilizing. 


Percentage of 

substance after 

adding to the 

evaporated milk. 


Influence of the added substances upon the 
coagulating point of the evaporated milk. 


Lactic acid 


.03 


Large decrease in coagulating point 


Sodium chloride .... 


.03 


Large decrease in coagulating point. 


Calcium chloride . . . 


.15 


Large decrease in coagulating point. 
Impossible to sterilize properly. 


Magnesium chloride. 


.15 


Large decrease in coagulating point. 
Impossible to sterilize properly. 


Sodium sulphate.. . . 


.15 


Slight decrease in coagulating point. 


Sodium acid phos- 
phate, NaHz PO4 


.15 


Large decrease in coagulating point. 
Impossible to sterilize properly. 


Ammonium chloride 


.15 


Large decrease in coagulating point. 
Impossible to sterilize properly. 


Tri sodium phos- 
phate Nas PO4 


.03 


Large increase in coagulating point. 


Sodium ammonium 
acid phosphate . . . 


.03 


Large increase in coagulating point. 


Ammonium 

phosphate 


.03 


Large increase in coagulating point. 


Sodium bicarbonate. 


.006 


1 oz. per 1000 lbs. raised coagulating point 1° F. 



I 



Coagulation Control 731 

All the chlorides tested greatly decreased the coagulating 
points. Sodium sulphate also decreased the coagulating point. 
Sodium acid phosphate decreased the coagulating point, while 
other phosphates increased it. Sodium bicarbonate increased it 
greatly. The small amounts required to influence the coagulating 
point shows how delicate is the balance, and how great is the in- 
fluence of the content of mineral salts. 

Sodium bicarbonate is in most respects the best product to 
use when it may be necessary to add some substance to the milk 
after other means have failed, in order to reduce the coagulating 
point. It is dependable, and of low cost. Its principal objection 
is the fact that it produces a large volume of carbon dioxide gas 
when it decomposes. This retards the condensing operation, 
since it makes it necessary for the vacuum pump to remove the 
gas that is formed. If the sodium bicarbonate is added to the 
evaporated milk after condensing, the gas is released during the 
sterilizing operation, and this causes the ends of the cans to bulge, 
giving the appearance of the cans being "swells" due to spoilage. 

Carbon dioxide is very soluble in cold water, so that moderate 
amounts that may be released during the sterilizing process are 
soon absorbed after the evaporated milk has cooled to room 
temperature. The practical limit of sodium bicarbonate to add 
after condensing is four ounces per 1000 pounds of the condensed 
product. When the sodium bicarbonate is added to the milk in 
the hot wells before condensing the practical limit should not 
exceed twelve ounces per 1000 pounds of finished product. The 
best plan is to add the greater part of the total amount required 
to the hot wells before condensing and to add only the final 
small amount required to standardize the coagulating point, to 
the condensed product before filling it into the cases, and there- 
fore before sterilizing. 

The use of an excessive amount of sodium bicarbonate also 
increased the color of the finished product after sterilizing. Every 
argument is in favor of its moderate use. 

Tri-sodium phosphate has the disadvantage of greater cost, 
but it does not produce any gases when added to milk. There 
may be conditions under which it can be used to advantage. 

Theoretically it would appear possible to utilize the above 
facts in standardizing the coagulating point of evaporated milk 



732 Evaporated Milk 

during the process of manufacture. This is only partially possible. 
Lactic acid cannot be used because its action is too violent, and 
its use is attendant with too many dangers. All the chlorides 
named cannot be used principally because of their bitter taste. 
More satisfactory means are known for decreasing the coagu- 
lating point than by adding foreign substances. These means 
will be discussed elsewhere in this chapter. The use of sodium 
bicarbonate affords a very satisfactory means for increasing the 
coagulating point. This will be further described in this chapter. 

Sommer and Hart- made a careful study of the influence of 
the mineral constituents upon the coagulating point of milk, and 
draw the following conclusions which in the main confirm the 
results reported above : — 

''In most cases coagulation can be prevented by the addition 
of citrates or phosphates, the coagulation being due to an excess 
of calcium and magnesium. However, in a few cases the addition 
of citrates or phosphates did not prevent coagulation, but rather 
hastened it. In these cases the addition of the proper amounts 
of calcium salts prevents coagulation, or at least raises the 
coagulating point. ' ' 

"From the data in Tables 135 and 136 we see that the calcium 
and magnesium are balanced by the phosphates and citrates of 
the milk practically in gram equivalent amounts. The balance 
of the four constituents, calcium, magnesium, citrates and phos- 
phates, largel,y determine whether a milk will coagulate or not. 
If calcium and magnesium are in excess, the milk will coagulate 
upon heating. If calcium and magnesium are properly balanced 
with the phosphates and citrates, the optimum stability obtains. 
If posphates and citrates are in excess, coagulation will also 
result." 

' ' Thus the coagulation of a milk sample on heating may be due 
either to an excess or a deficiency of calcium and magnesium. 
We may explain this in the following manner. The casein of the 
milk is most stable with regards to heat coagulation when it is in 
combination with a definite amount of calcium. If the calcium 
combined with the casein is above or below this optimum the 
casein is not in its most stable condition. The calcium in the milk 
distributes itself between the casein, citrates and phosphates 
chiefly. If milk is high in citrate and phosphate content more 



Coagulation ControIv 



72>?> 



calcium is necessary in order that the casein may retain its 
optimum calcium content after competing with the citrates and 
phosphates. If the milk is high in calcium there may not be 
sufficient citrates and phosphates to compete with the casein 
to lower its calcium content to the optimum. In such a case 
the addition of citrates or phosphates makes the casein more 
stable by reducing the calcium content. The magnesium functions 
by replacing the calcium in the citrates and phosphates." 

"In most cases the coagulation is due to an excess of calcium 
and magnesium. It is possible to balance this even by citrates, 
phosphates, carbonates and other salts. It is also stated that 
danger of coagulation may be avoided in the actual practice of 
condensing milk by controlling the preheating period, using 
higher temperatures. This may have the effect of lowering the 
soluble calcium content by precipitating part of it as insoluble 
calcium phosphate." 

In the experiments of Sommer and Hart twenty-five out of 
thirty which coagulated contained an excess of calcium and 
magnesium over citrates and phosphates. Those which liad the 
lowest excess did not coagulate. 



TABLE 135. 

Balance Between Calcium and Citrates. 



25 CO. milk plus 


Coagulation 
time 


M/2 calcium 
acetate 


M/2 sodium 
citrate 


H„0 




cc. 
0.0 


cc. 
0.0 


cc. 
1.6 


Min. 

4 


0.4 


0.0 


1.2 


V2 


0.4 


0.2 


1.0 


40. 


0.4 


0.4 


8 


40. 


0.4 


0.6 


6 


21/4 


0.4 


0.8 


4 


2 



734 Evaporated MiIvK 

TABLE 136. 
A Sample in Which Calcium Prevents Coagulation. 



25 cc. Milk Plus 


Coagulation 
time 


M/2 calcium 
acetate 


M/2 sodium 
citrate 


H,0 




cc. 
0.0 


cc. 
0.0 


cc. 
0.8 


Min. 
1% 


0.2 


0.0 


0.6 


20 


0.2 


0.1 


0.5 


iy4 


0.2 


0.2 


0.4 


1 


0.2 


0.3 


0.3 


V4 


0.2 


0.4 


0.2 


V4 



(d). Influence of concentration. — The degree to which the 
fresh milk is condensed has a large influence upon the coagulating 
point of the evaporated milk. This is illustrated by the experi- 
ment reported by Hunziker'' as shov^^n in Table 137. 

TABLE 137. 

Showing the Increase of the Per Cent of Acid as the Concentration of the 

Evaporated Milk Increases and Its Effect on the Curdling of the Casein. 



Lot No. 


Concentration 


Per cent acid 


Condition of casein 


1 


1.58:1 


.34 


Not precipitated 


2 


1.74:1 


.34 


Not precipitated 


3 


1.9 :1 


.40 


Not precipitated 


4 


1.99:1 


.43 


Not precipitated 


5 


2.11:1 


.48 


Small lumps of curd 


6 


2.25:1 


.54 


Large lumps of curd 



In normal evaporated milk at a concentration around 7.80 
per cent of fat and 25.50 per cent of total solids, every 20 pounds 
of water added or removed per 1000 pounds of the condensed 
product, lowers or raises, as the case may be, the coagulating 
point I'^F. This is an important factor that can be used in con- 
trolling the sterilizing process. 



Coagulation ControIv 735 

In uormal evaporated milk the influence of concentration has 
been a large determining factor in establishing the present 
standards which control the manufacture and sale of this product. 

The factor of concentration was studied by Sommer and Hart^. 
They concluded from their experiment that "not only the con- 
centration of the casein influences the coagulating point, but also 
the concentration of the serum." 

The intricacy of the above reactions is well illustrated by the 
case of the salts of sodium. Sodium chloride and other sodium 
salts when added to evaporated milk greatly lowers its coagu- 
lating point, while sodium bicarbonate and certain other sodium 
salts have exactly the opposite effect. Much remains to be 
learned regarding the influence of both basis and acidic radicals 
upon the coagulating point of milk by heat. 

(e). Influence of products of bacterial growth, other than 
acid. — A considerable number of bacteria are known that have 
the power to produce rennet or rennet like substances, which have 
the power to curdle milk. The action of rennet upon milk forms 
the basis of the cheese industrj^, since this makes it possible to 
coagulate the casein at a low temperature, and in the presence 
of a low acid content. 

Rogers' reports interesting experiments that prove the above 
statements. He states: "Milk, inoculated with a small amount 
of bacteria known to produce rennet actively, was held at room 
temperature for three hours. With this was held part of the milk 
without inoculation which, when evaporated to the standard con- 
centration, curdled at a temperature of 240 degrees F. That 
inoculated and held three hours before evaporating, curdled at 
226 degrees F., although the acidity was identical with the 
uninoculated fraction." The results of his experiments are shown 
in Table 138. 

The presence of rennet producing type of bacteria is largely 
favored by unsanitary conditions either at the farms where the 
milk is produced, or in the plant where the fresh milk is 
manufactured into evaporated milk. Unclean milk pails and 
milk cans are the most prolific cause of trouble upon the farm. 
Unclean utensils, milk pumps and milk pipe lines are the most 
prolific cause of trouble in the plant. The rigid enforcement of 



736 



Evaporated Milk 



TABLE 138, 
Effect of Rennet Forming Bacteria on Curdling Temperatures. 



Inoculation 


Time of 
action 
(hours) 


pH 


Coagulation 

temperature 

degrees F. 


None 

Rennet-forming bacteria, 


10 cc. 


3 
1^ 


6.33 


240.4 
226.4 






3 


6.33 


226.4 


None 




2 




246.2 


Rennet 


.0175 


1 




226.4 




gms. 


2 




213.6 



sanitary rules at all points will do more than anything else 
to eradicate a trouble of this kind in an evaporated milk plant. 

(f). Influence of method of forewarming in the hot wells. — 
The method of forewarming the milk in the hot wells exerts a 
large influence upon the coagulating point of the flnished product. 
This fact is of large practical value in the manufacture of 
various condensed milk products, and mention is made of it in 
different chapters of this book. 

The exact cause of this action is not fully understood because 
of lack of experimental proof. 

Sommer and Hart, just quoted, state that this may be caused 
by the precipitation of part of the soluble calcium content into 
the insoluble calcium phosphate, but no experimental proof is 
submitted, 

Tricalcium citrate when freshly prepared is readily pre- 
cipitated upon heating, probably due to decreasing solubilities at 
increasing temperatures, and the theory is frequently advanced 
that this is the cause of the changes produced in milk by fore- 
warming. Experimental proof is lacking here also, and practical 
evidence is contrary to this view. Further reference will be 
made to this matter in another part of this chapter. 

The action of heat upon the coagulation of the albumin in the 
milk may very readily be the most important factor controlling 
this action. It has long been known that the extent of the 
coagulation of albumin by heat varies with both the temperature 
and the time of exposure of the milk to the heat. The liigher 
the temperature and longer the time of heating, the more of the 
albumin will become insoluble by heat. 



Coagulation CoNTRoiy 737 

Cavanaiig'li and Latzer^ report the following amount of 
albumin precipitated under different conditions of heating, the 
results being the average for ten experiments. 

When heated to boiling ,37 per cent albumin precipitated. 
When boiled for five minutes .42 per cent albumin pre- 

cipated. 
When heated at 15 lbs. pressure for 80 minutes .44 per cent 
albumin precipitated. 

The above results were obtained by difference from their 
published results. 

When milk is heated no apparent separation or coagulation of 
the albumin takes place, but it undergoes a change that causes 
that part of it wliich has changed to separate with the casein 
when acid is added. The values given above represent the 
amount of albumin which separated along with the casein when 
acid was added in making the determination of acid insoluble 
protein. 

The preponderance of evidence at the present time is that the 
changes in the albumin content of the milk by heating may be 
largely responsible for the differences in the behavior of evapo- 
rated milk in sterilizing, which milk had been previously heated 
differently in the hot wells. 

Heating- of the Milk in the Hot Wells. — As already noted, 
when milk is properly heated in the hot wells, it undergoes 
certain changes which play an important part in the sterilization 
of evaporated milk. 

Unless the milk is properly heated in the hot wells, there is 
every opportunity for the milk to undergo certain other chemical 
changes, Avhich will have a very bad effect upon the ultimate 
product. The reasons for these other changes are not definitely 
understood at the present time, but all the evidence is in favor 
of the view that when the heat is improperly applied to the milk 
in the hot wells, certain chemical changes occur in the casein 
and albumin molecules. The extent of these changes follow 
closely the law of mass action. That is, when the steam is 
introduced into the milk at a high pressure, or in large volumes, 
the agitation of the milk at the point of the introduction of the 
steam is not rapid enough to transmit the heat uniformly to all 
parts of the milk in the hot Avell. The result is that the local 



738 Evaporated Milk 

action of the steam upon the milk is sufficiently great to overheat 
the milk beyond the coagulating temperature of the casein itself. 

The above unfavorable effect is almost negligible v^here 
jacketed hot wells are used, and the worst effect manifests itself 
where plain hot wells are used — that is, where the milk is heated 
in the hot wells by live steam. By using the proper care, it is 
possible to heat the milk in plain hot wells, using live steam only, 
without causing any injury to the milk. It has been learned by 
experience that no bad results follow. when eight minutes are 
taken to forewarm one thousand pounds of fresh milk to the 
desired temperature in the hot wells. The only safe method to 
follow is to place a pressure reducing valve upon the steam feed 
line which is used to supply the hot wells. This valve should 
be set to operate at a pressure not in excess of 10 pounds per 
square inch. 

Where the jacketed hot wells are used, it is best to bring the 
milk up to about 170° F., and then to complete the heating from 
that point up to the right temperature by means of live steam, 
introduced directly into the milk. In a number of cases, the 
milk is passed through special heaters on the way to the hot 
wells and forewarming is then completed in the hot wells with 
live steam. As a rule, this is a very satisfactory method. 

Steam Distribution in the Sterilizer. — Even distribution of 
steam in the sterilizer is necessary, no matter what style of 
sterilizer is used, or whether superheated water or steam alone 
is used for sterilizing. A frequent cause of uneven sterilization 
lies in the fact that the perforations in the steam distributing 
pipes become enlarged, due to the wearing effect of the steam 
while passing through the perforations. This is especially likely 
to be the case where the steam distributing pipes are made of thin 
brass tubing. It is recommended as far as practical, that brass 
pipe, iron pipe size, be used for this purpose. There is much less 
danger from enlarging of the perforations when this pipe is 
used, than when the thin brass tubing is used. It is especially 
suggested that iron pipe never be used for this purpose, although 
some makes of sterilizers are noAv furnished with the distributing 
pipe of iron. When iron is used, the openings are likely to be- 
come enlarged not only from the action of the steam, but also 
from the rusting of the iron. 



Uniforini SturiIvIzation 739 

It frequently happens that the cap may come off of one of the 
steam pipes, or the pipes may become disconnected at the inlet, 
so that for all of the above reasons, it is very desirable to check 
up the different sterilizers very carefully from time to time. 

The Evaporated Milk Controller affords a particularly efficient 
means for checking up the evenness of sterilization. This is 
accomplished by means of the viscosimeters which accompany the 
Controller. Detailed instructions for making the viscosity tests 
will follow further in this chapter. 

When checking up by means of the viscosimeter, it is sug- 
gested that at least three sets of cans be taken out of each 
sterilizer. The first set is to be taken from the top of one section 
in the case of a Fort Wayne Sterilizer, and from the top of the 
cage in the case of a Berlin Sterilizer. The second set is to be 
taken from the middle of the section or cage, and the third set 
from the bottom of the section or cage, in the two respective 
sterilizers. In each case, one sample is to be taken from near 
each of the two ends, and one from the center of the section or 
cage, making a total of nine samples in all. By following this 
method, it becomes possible to get an accurate check upon the 
distribution of the steam in the different parts of the sterilizer. 

TABLE 139. 

Determining Steam Distribution in the Sterilizer. 



Location of Sample in Sterilizer 


Viscosity 




retardation 


Right end 4 cans from end, top row of cans 


115° 


Right end 4 cans from end, center row of cans 


100° 


Right end 4 cans from end, bottom row of cans 


120° 


INIiddle of cage, top row of cans 


132° 


Middle of cage, center row of cans 


175° 


Middle of cage, bottom row of cans 


265° 


Left end 4 cans from end, top row of cans 


150° 


Left end 4 cans from end, center row of cans 


65° 


Left end 4 cans from end, bottom row of cans 


170° 



As the figures show in the above example, the sterilizer in 
question cooked the milk considerably heavier in the center of 
the cage than at the two ends, particularly the inside cans at the 
two ends. By changing the steam circulation, and particularly 
by watching the level of the water in the sterilizers, it was 
possible to improve the uniformity of the sterilization. 



740 Evaporated Milk 

Standardization for Fat and Total Solids. 

After the milk has been condensed and cooled, the next step 
is to test the milk for butter fat and total solids. If the plan is 
followed of standardizing the finished product, both for fat and 
total solids, this should be done before the samples are taken out 
for the tests upon the Controller, In case that the plant follows 
the plan of standardizing with water only, the milk should be 
standardized down with the water to the required basis, and 
the samples then taken out for the tests upon the Controller. It 
is very important to coordinate the tests upon the Mojonnier 
Tester for butter fat and total solids with the tests upon the 
Evaporated Milk Controller. If this is done, it will be possible 
to obtain uniform results both from a chemical and physical 
standpoint upon the finished product. 

Ten Per Cent Sodium Bicarbonate Solution. 
Prepare as follows : 

(1). Weigh bottle empty, upon Torsion Balance to .01 ounce. 

(2). Add 3 ounces bicarbonate of soda to the bottle. 

(3). Add 27 ounces warm water to the bottle. 

Shake thoroughly until the bicarbonate is all dissolved. Draw 
out as needed into the dispensing bottle, filling the same not 
over half full. Keep remainder tightly corked in the stock bottle 
until needed. Should the bicarbonate crystallize out, prepare 
a new lot. 

If prepared according to the above directions, the solution 
will contain exactly 10% sodium bicarbonate. 

How to Add Sodium Bicarbonate to the Sample Cans. — 

Arrange in a row five open-top cups, marked— X-1-2-3-4. These 
cups are furnished with the Controller. Cup marked X is blank, 
to which nothing is added. To cup marked No. 1 add one charge 
of sodium bicarbonate from the dispensing burette. This is the 
amount contained between the upper two graduations on the 
burette. 

To cup marked No. 2 add two charges, to cup No. 3 add three 
charges. To cup No. 4 add four charges. Examination of the 
dispensing burette furnished with the Controller will indicate 
liOAV the above quantities are to be added; that is, the burette 
is graduated into four separate charges. The unit with one 



SteriIvIzation Control 741 

siugle charge contains the equivalent of one ounce of sodium 
bicarbonate, to one thousand pounds of evaporated milk. Each 
successive charge is a multiple of this unit. In dispensing the 
bicarbonate solution, it is best not to fill the bottle more than 
half full. When filling the burette, the solution shoukl be 
allowed to flow into it slowly in order not to trap in the air. 
If air is trapped into the burette, it is difficult to remove it, and 
ill such a case it is best to run oat whatever solution may be in 
tJie burette, and to put in a new supply. 

Whenever the quality of the milk is bad, it may be necessary 
to add more than the above indicated number of charges of 
bicarbonate solution to the sample cans. In such cases any 
nmltiples of the above number of charges may be added. The 
ratio of ounces of bicarbonate to one thousand pounds of milk 
Avill remain the same, being increased simply by the number of 
charges added to each sample can. 

Preparing the Five Sample Cans for the Sterilizer. — After tlie 
five open-top cups have been treated with bicarbonate as indicated 
in the preceeding section, they are transferred to the Torsion 
Balance and exactly six ounces of milk are weighed into each 
cup. This can be done by taring the entire set of empty cups, 
and then weighing six ounces of evaj)orated milk into each 
separate cup. 

One set of five empty cans are now marked in the same manner 
as the cups to which the- bicarbonate solution was added, namely, 
as follows : X:= can containing no bicarbonate ; l=can containing 
equivalent of one ounce bicarbonate per thousand pounds of 
evaporated milk; 2=can containing equivalent of two ounces to 
one thousand pounds of evaporated milk; 3:=can containing 
equivalent of three ounces to one thousand pounds of evaporated 
milk and 4= can containing equivalent of four ounces to one 
thousand pounds of evaporated milk. 

The cans are now placed in pairs under the two can vent 
hole filler, furnished with the controller, and the cups with the 
milk and bicarbonate marked corresponding to the empty cans 
are now emptied into the filler. Care must be taken to keep the 
cans in the proper order. 

After filling, the cans are to be tipped, using preferably rosin 
solder. Should none of this solder be available, then great care 



■42 



Evaporated Milk 



must be exercised not to let any of the flux from the zinc 
chloride solder enter the cans. Zinc chloride flux has a very bad 
effect upon the milk, and will completely change the results. 

Sterilizing- the Five Sample Cans. — The five sample cans pre- 
pared as above are now ready for the sterilizer. Place these in 
the cage and fasten the lid securely, and also turn down the 
screws in order to hold all of the cans securely in place. Adjust 
the cage in the sterilizer by means of the thumb screw upon the 
right hand side in order to keep them from having end play. 
Close the sterilizer door securely so tliat no steam escapes during 
the sterilizing process. 

Be sure to provide circulation of the steam through the vent 
upon the pipe surrounding the thermometer. This little vent 
should be kept open during the entire sterilization operation. 
Fill the small pilot sterilizer to a point half way upon the gauge 
glass. Turn on the switch to start the motor in operation. Open 
the "steam start valve" and take five minutes to let the heat 
reach 190° F. or 3 upon the sterilizer scale. Then let the heat 
come up gradually from 190 to 240° F. or from 3 to 8 upon the 
thermometer, taking one minute for each 5° as indicated in the 
following table : 

TABLE 140. 
Relation Temperature, Scale Reading, and Coming-Up Time. 



Actual temperature in 
Fahrenheit degrees 


Actual reading upon 
thermometer scale 


Point at which mercury 

sliould be at any given 

time coming up. 






Minutes 


240 


8 


20 


230 


7 


18 


220 


6 . 


16 


210 


5 


14 


200 


4 


12 


190 


3 


10 



Where sterilizing is done with steam only, without using 
superheated water, it is recommended twenty minutes be taken 
for coming up. The above table is arranged upon this basis. 
The table, liowever, can be readily adapted to a system requiring 
fifteen minutes for coming up, by taking five minutes to come 
up to the point marked 10 upon the table, or to 190° F. 



Viscosity ControIv 743 

It is also recommended that in the pilot sterilizer, the samples 
be cooked to 243° F. and that the jump from 230 to 243° be 
made in two minutes. It is very important to know the exact 
second when the mercury column reaches 243°. The milk should 
be held at this temperature for fifteen minutes to the exact 
second. 

How to Cool the Five Sample Cans. — The instant that the 
clock indicates that the samples have been sterilized as indicated 
above, both discharge valve and cold water valve should be 
opened simultaneously. It is best to cool the five samples to 
about 75° F. This should take not to exceed five minutes, depend- 
ing upon the temperature of the water available. This is some- 
thing each operator will have to judge for himself. 

How to Test Sample Cans for Viscosity. — As soon as the 
sample cans are cooled in the sterilizer, as indicated above, the 
outside of the cans are dried ; and the cans are then opened and 
each can is placed in the proper position in the Mojonnier-Doo- 
little viscosimeter rack. It will be noted that the same scheme 
of marking the spaces upon the viscosimeter rack has been 
observed as in the case of marking the cans. It is very desirable 
to cool the samples to as nearly 75° F. as possible. If this is not 
done, the viscosity should be corrected for temperature, using the 
scale of corrections given in Table 141. Make the viscosity tests 
as follows : 

(a). Different sizes of balls are furnished, corresponding to 
the product that it may be desired to test for viscosity. A special 
viscosity ball is furnished in the case of evaporated milk, and this 
is not interchangeable with any other ball for this purpose. 

(b). Fasten one end of the wire in the knurled nut upon the 
top of the bent support, and the other end in the dial. Adjust 
the vertical position of the dial by raising or lowering, until the 
small lug on the bottom of the dial is in the proper position to 
engage the trip upon the right and side of the stand, 

(e). Adjust the horizontal position of the dial until zero 
degrees is in a Ijne with the pointer upon the front of the frame 
when the dial is balanced in the air. Center the dial in the open 
circle by means of the adjusting screws on the under side of the 
frame. Make a test for viscosity directly in the small size cans. 



744 



Evaporat£;d M11.K 



Properly center the can by means of the automatic arrangement 
provided for that puri)ose. 

(d). Lower the ball into the can of milk; turn the dial 
clockwise one revolution ; stopping when zero degrees upon the 
dial is in line with the pointer upon the front of the frame. 
Hold the dial in place by means of the lug and trip. When ready, 
sharply release the trip, note the degree where the dial stops, 
just before it starts upon the return round. This will occur after 
the dial has made one complete, and part of tlie second revolution. 
The degree at which the dial stops will represent the viscosity 
of the sample. The greater the viscosity, the larger the degree 
reading will be. The observed viscosity should always be reduced 
to a standard temperature. The higher the temperature the 
lower the viscosity will be or vice versa. The proper corrections 
to apply either above or below 75° F. are given in Table 141. 
A diflferent correction applies upon freshly sterilized evaporated 
milk, than upon the same product after it has reached the packing- 
room, in the usual methods of handling, as shown in the two 

tables. 

TABLE 141. 

Correcting Viscosity of Evaporated Milk to 75° F. 



STERILIZING ROOM 


PACKING ROOM 


Temp. 


Take off 


Temp. 


Add. on 


Temp. 


Add. 


Temp. 


Take off 


Temp. 


Add. on 


Temp. 


Add. 


Deg. 


Deg. 


Deg. 


Deg. 


Deg. 


on 


Deg. 


Deg. 


Deg. 


Deg. 


Deg. 


on 


F. 


R. 


F. 


R. 


F. 


Deg. 
R. 


F. 


R. 


F. 


R. 


F. 


Deg 
R. 


65 


25 


76 


.-> 


89 


24 


60 


15 


75 





88 


10.0 


66 


22 


77 


4 


90 


25 


61 


14 


76 


1 


89 


10.5 


67 


19 


78 


(i 


91 


26 


62 


13 


77 


9 


90 


11.0 


68 


16 


79 


8 


92 


27 


63 


12 


78 


3 


91 


11.5 


69 


13 


80 


10 


93 


28 


64 


11 


79 


4 


92 


12.0 


70 


10 


81 


12 


94 


29 


65 


10 


80 





93 


12.5 


71 


8 


82 


14 


95 


30 


66 


9 


81 


6 


94 


13.0 


72 


C 


83 


10 


96 


31 


67 


8 


82 


7 


95 


13.3 


73 


4 


84 


18 


97 


32 


68 


7 


83 


7.5 


96 


13.0 


74 


2 


85 


20 


98 


33 


69 


6 


84 


8.0 


97 


13.9 


7.5 





86 


21 


99 


34 


70 


.) 


85 


8.5 


98 


14.2 






87 


22 


100 


35 


71 


4 


8() 


9.0 


99 


14 . 5 






88 


23 






72 
73 
74 


3 

2 

1 


87 


9.5 


100 


14.8 



Record the viscosity of each of the sample cans tested, as 
indicated above. Further instructions will follow as to the 
method of applying information thus obtained. 

How to Test Cans for Color. — Just as soon as the samples 
have been tested for viscosity, they are to be moved under the 
colorimeter. The can that has been picked out as the standard 



vStkkiuzation Control 745 

* 

should now be compared with another can from a run that was 
selected as being of the proper color, or it can be compared to 
any other standard that may be desired. If the milk is standard- 
ized for fat and total solids, and if the sterilization is kept within 
narrow limits as regards time and temperature of sterilization, the 
fluctuation from batch to batch should be very small. The above 
cire the largest factors that control the color. The color of evapo- 
rated milk also increases gradually with age. so that in selecting 
the stajidard. it is desirable to clioose freshly prepared goods. 

Correlations That Can be Used to Establish the Proper Steril- 
izing Method. — A number of very important relations have been 
correlated by careful experiment, and the facts thus known are 
used as a basis for establishing the exact temperature and time 
upon which any batch of evaporated milk may be sterilized, in 
order to obtain the best possible product. These relations are as 
follows : 

A retardation of 40"^ in the viscosity^ (a) 1 ounce solid sodium 
bicarbonate per 1000 pounds of unsterilized evaporated milk, 
standardized to 7.8 per cent butter fat and 25.50 per cent total 
solids; (b) or 1^ F. in the sterilizing temperature, at the holding 
point of 240 ' ¥. with the same coming up time ; (c) or one minute 
of time at a holding temperature of 240° F. ; (d) or 2° F. upon 
Ihe temperature to which the milk is heated in the hot wells 
under 212° F., (e) or 20 lbs. Avater per 1000 lbs. evaporated milk. 
The above viscosity relation holds only with viscosities above 
50' or beloAv 300"^, upon the Mojounier-Doolittle Viscosimeter. 

The above are most important and fundamental facts to bear 
jji mind, and when once understood they will greatly simplify 
tlie adjusting of the correct process for sterilizing evaporated 
milk. This is best illustrated by the following example : 

A batch of milk has been standardized to 7.8 per cent butter 
fat and 25.50 per cent total solids. Total weight of evaporated 
milk in tlie batcli equals 24,000 lbs. The five sample cans from 
the pilot sterilizer tested for viscosity as follows : 

Can X=235° retardation 

Can 1=190-" retardation 

Can 2=150° retardation 

Can 3=105° retardation 

Can 4=: 70° retardation 



746 EvAPORATi-D Milk 

• 

Now, it has been found by experience that 150° retardation 
is the proper viscosity for evaporated milk, just as it comes from 
the sterilizers. This refers to evaporated milk made for domestic 
consumption. Evaporated milk intended for export purposes 
should have a viscosity considerably higher than this, namely, 
around 200° retardation. It is not desirable to send out evapo- 
rated milk upon the market which contains as much as 150° 
retardation of viscosity. A considerable part of the viscosity 
which the milk has, when it comes from the sterilizers, is lost 
during the handling to which the milk is subjected from the 
time it leaves the sterilizers until it is ready to leave the shipping 
department. It is believed that the proper viscosity that the milk 
sliould have upon leaving the shipping department during the 
spring and summer months should be between 80° and 100° 
retardation. In the early fall and winter months, it should not 
be over 80°. The warmer the milk is during the handling opera- 
tions, either before it leaves the plant, or after it passes into the 
hands of the retailer, the less will be the viscosity of the milk by 
the time it reaches the consumer. Upon the other hand, it is 
equally important over the winter months to avoid excessive 
dscosity, as in that case the evaporated milk is likely to appear 
curdled when used in coffee, or even when diluted with water in 
the home. 

Referring back to the viscosity tests of the five cans, it will 
be seen that the can marked No. 2 is the one that most nearly 
approaches the standard aimed for, since this is found to have 
a viscosity of exactly 150° retardation. 

It is always desirable to eliminate the use of sodium bicarbon- 
ate as much as possible. In this particular case it will be 
possible to eliminate its use entirely, as indicated by referring 
back to the above correlations. That is, can No. 2 could be 
adjusted to have a sterilizing record of 243° F. at a holding time 
of fifteen minutes by adding two ounces of sodium bicarbonate 
per thousand pounds of evaporated milk. Upon the other hand, 
since it is more desirable to get along without using any bicarbon- 
ate, very nearly the same results can be obtained by sterilizing 
the batch at 241° F. for fifteen minutes holding time. It is not 
recommended that the holding time be reduced under fifteen 
minutes, as this is as short as it is desirable to make it. Under 



Strriuzation ControIv 747 

the circumstances, tlie two alternatives in the above problem are 
first to add 2 ounces of bicarbonate per thousand pounds of 
finished product, or to reduce the sterilizing temperature 2°. 

The milk in the tank is now ready to be filled into the cans. 
It is important to know that the filling of the milk should not 
be started until all of the tests upon the Controller have been 
completed. 

How to Add Sodium Bicarbonate to Milk Before Sterilizing. — 

In case that it is necessary to add sodium bicarbonate as might 
have been done in the preeeeding problem, this should be done 
as follows : 

The amount to be added is to be determined entirely by the 
viscosity tests of the milk upon the five sample cans. In the above 
example it was noted that can No. 2 showed a viscosity of 150° 
retardation. Since this is the standard of viscosity that it is 
desired to reach, bicarbonate should be added in the amounts 
indicated, being in the case of the milk under question, 2 ounces 
per each one thousand pounds of vaporated milk on hand. Since 
the batch contained 24,000 pounds, it will now be necessary to 
weigh out 48 ounces of the solid bicarbonate upon the Torsion 
Balance. This is then dvimped into a ten gallon milk can, a small 
amount of water, with a little evaporated milk, usually just the 
sample cans, is then added to the bicarbonate in the can. The 
entire mixture is brought to a vigorous boil, by means of the 
steam hose attached to the Controller. The boiling should be 
continued until the gas has been fairly well expelled. This will 
not eliminate all the gas which is contained in the bicarbonate, 
but it will eliminate the greater part of it, since sodium bicarbon- 
ate is not a stable compound, and is partly broken up by heat 
under these conditions. The solution may now be added to the 
evaporated milk in the holding tank. The milk should be agitated 
while the bicarbonate solution is being added, and the bicarbon- 
ate solution should be poured in very slowly. As the amount 
used is usually small, it is not necessary to cool it back before 
adding it to the milk, as the amount is not sufficiently large to 
increase the temperature of the milk in the hold-over tank. 

It is very important to allow the agitators to run for from 
ten to twenty minutes before starting the fillers. The time neces- 



748 Evaporated Milk 

sary here depeuds upon the efficiency of the agitators, and it can 
be determined accurately oul}^ by careful experiment. 

How to Adjust the Sterilizing Records Upon Different Sizes of 
Cans. — Different sizes of cans require difit'erent sterilizing tem- 
peratures to produce the same viscosity. Tall size cans require 
1° more heat upon a 15 minutes' run that does baby size. For 
example, upon the same batch of milk, the record would be 
240° F. for 15 minutes for baby size, and 241' F. for 15 minutes 
upon tall size. 

How to Change the Temperature of Heating the Milk in the 
Hot Wells. — The method of changing the temperature necessary 
to heat the milk in the hot wells is indicated by the following 
example : 

Sample can marked X cools 70° retardation. 

Sample can marked 1 cools 40' retardation. 

Sample can marked 2 cools 30° retardation. 

Sample can marked 3 cools 20° retardation. 

Sample can marked 4 cools 15° retardation. 
As the results indicate, the blank can marked X which con- 
tains no bicarbonate shows viscosity under the standard desired, 
namely 150° retardation. This is short in viscosity to the 
extent of 80° retardation, which is equal to 4° F. upon the 
temperature to which the milk is heated in the hot wells under 
212° F. upon the above mentioned correlated values. Granting 
that the milk has been brought to a temperature of 212° in the 
hot wells, it develops from the results of the viscosity tests that 
the milk in this batch had been forewarmed 4° more than should 
have been the case, that is, it should have been forewarmed at 
208° F. Assuming that the milk in this particular case is now 
all in" the tank, it is, of course, impossible to go back to correct 
the forewarming of the milk in the hot wells. All that can be 
done is to increase the sterilizing temperature from 243 to 245° F. 
at the standard holding time of fifteen minutes. 

Tt is always recommended that a preliminary test be made of 
the milk before the condensing is all completed. In the above 
problem, it is recommended that the foroAvarmhig of the milk of 
the succeeding day be modified upon tln^ basis of results obtained 
Avith the batch in question, that is, granting that climatic con- 
ditions and the general milk supply remain the same. In that 



b'TERiiwizATioN Control 



749 



case, it is sugge.^tecl that with a plant having four batches of raw 
milk, each containing about twelve thousand pounds, that im- 
mediately after three of the batches are condensed and cooled, 
and well mixed together in the hold-over tank, that a preliminary 
sample of these batches be run. If it is found that the milk from 
these three batches is of too low viscosity, the last batch can be 
forewarmed at a sufficiently low temperature to increase the 
viscosity of the three preceding batches to the desired point. It 
is possible to condense the milk at as low a forewarming tempera- 
ture as 140° F. However, when this is done, care must be taken 
to see that a good sterilizing record is used, as otherwise there 
may be danger of spoilage of the milk. 

It is not recommended that the milk taken for these pre- 
liminary tests be standardized for fat and total solids. If the 
tests of the milk at the strike is carefully watched, the product 
will be near enough to chemical standard so as not to affect 
greatly the physical properties. If this plan is followed,, plenty 
of time is available to make the tests upon the Controller before 
the forewarming of the last batch is completed for the day. If 
necessary, the last batch can always be held up for a little 
while in order to complete this test, and it is recommended that 
this be done rather than sacrifice on the physical properties of 
the finished product. 

Why Evaporated Milk Sometimes Fails to React with Sodium 
Bicarbonate. — Conditions are very frequently encountered in 
evaporated milk plants under which it is impossible to improve 
the quality of the product by adding bicarbonate of soda. This 
is illustrated by the following set of viscosity tests made upon 
one batch of milk that was standardized to exactly 25.50 per 
cent total solids. 

TABLE 142. 
Evaporated Milk That Failed to React to Bicarbonate of Soda. 



Ounces sodium bicarbonate added 
per thousand pounds evaporated 
milk. 



Viscosity after sterilizing 240° F. 
for fifteen minutes. 





o 

4 

6 

10 



112° retardation 
180° retardation 
280° retardation 
280° retardation 
Too heavy to get viscosity. 



750 Evaporated Milk 

As the above results indicate, the addition of the bicarbonate 
had just exactly the opposite effect to that vs^hen added to milk 
that was handled in the way that was recommended above. That 
instead of reducing the viscosity of the milk it increased the 
viscosity. This plainly indicated that the milk had undergone 
chemical changes in the casein molecule. The factors that will 
bring about the above mentioned conditions are as follows : 

(1). Improper forewarming of tlie milk in the hot wells. 
This point has already been mentioned. 

(2). Homogenizing the milk at too high a pressure. The 
trouble that may result from this cause can be determined experi- 
mentally under the conditions which exist at each particular 
plant. It is seldom desirable to homogenize the milk much above 
2,000 pounds pressure, 

(3). Handling of the milk by the so-called "wash process," 
Under this process the milk is condensed to about %. its original 
volume. It is then cooled, and an amount of water added slightly 
in excess of that required to bring the milk back to the desired 
consistency, and finally recondensing the surplus of water added 
to the milk. This is a wasteful process, which exerts a very bad 
effect upon the milk, 

(4). Brine leaks from the cooling coils at the condensed 
milk cooler. This is a frequent cause of trouble. 

If care is taken in the plant, all of the above conditions that 
tend to change the chemical composition of the milk can be 
avoided, thereby making it psssible for the milk to react to 
sodium bicarbonate in a perfectly normal way. 

How to Reduce the Amount of Bicarbonate Necessary to 
Add. — It is always very desirable to keep the amount of bicarbon- 
ate down to the very lowest minimum. The indiscriminate use of 
this product may lead to several serious consequences. In the 
first place, the gas from the bicarbonate is released during the 
sterilizing process, and this will cause the ends of the can to 
bulge. If an excess is used, it becomes impossible to again press 
the ends back into normal position, so that they may be bulged 
when sent to the consumers. In the second place, an excess of 
bicarbonate is bound to increase greatly the color of the milk, 
making the milk much darker than it would be normally. 



Sterilization Control 751 

The following steps can be taken to reduce the use of bicar- 
bonate. Observation that the proper methods of handling the 
milk are practiced upon the dairy farms. It is particularly 
necessary to have the milk well cooled and kept in well cleaned 
cans. Also, that all utensils in which the milk is handled are kept 
clean and sterile at all times. Colostrum milk should be rejected. 
Changes in the chemical composition of the milk are responsible 
more than anything else for the use of bicarbonate. In localities 
where summer dairying predominates, the change in the composi- 
tion will become apparent more in the fall of the year. Upon 
the other hand, where winter dairying predominates, the same 
trouble may be encountered at other seasons. The trouble is, 
however, very much more prevalent in the fall of the year and 
during the winter months than during all of the other seasons 
(iombiued. It is possible that the fact that the cows are being 
placed upon dry feed exerts some influence upon this condition. 
This is by far tlie most important of all conditions which compel 
the use of bicarbonate. No means are known to science at the 
present time whereby these conditions can be successfully over- 
come except by means of sodium bicarbonate. 

Milk that is too long in transit to the factory is likely to 
develop an excess of acid, and may, therefore, require bicarbonate. 

Milk that is held in storage at the factory at too high tempera- 
tures, or for too long a time before it is heated in the hot wells, 
also develops excessive acid. This is a very frequent cause of 
trouble, and frequently such milk is changed too much to make it 
possible to handle it at all. 

Improper cooling of the milk after it leaves the vacuum pan, 
and holding the milk in the storage tanks too long before it goes 
to the fillers are all contributing causes. 

Unsanitary methods in the plant itself, that is, improper 
cl6aning of the vacuum pan, or of the hot wells, or homogenizer, 
or storage tanks, or filling machines, can all become contributing 
causes to this trouble. 

The handling of two days' milk, sometimes practiced over the 
winter months, is also responsible for a great deal of trouble 
along these lines. Tlu're are very few dairies tliat are equipped 
to hold milk over in good condition for two days. The milk, 
therefore, is exposed to all kinds of unfavorable conditions and 
this, of course, affects the quality of the finished product. 



752 EVAPORATHID MiLK 

SEASONAL VARIATIONS IN THE COAGULATING POINT OF 
EVAPORATED MILK. 

The seasons do not in themselves directly intiiienee the co- 
agulating point of evaporated milk, but indirectly they are a large 
factor, and year after year changes in the coagulating point fol- 
low closely the changing seasons. Paralleling the changing 
seasons, and probably the direct causes of the variations in the 
coagulating points can be mentioned : 

(1). The changes in the milk due to the lactation period. — If 

the coAvs supplying a given plant, always freshen at about 
the same time of the year, then more marked will be the influence 
of the lactation period. These differences can be considerably 
equalized by arranging for the cows to freshen at dift'erent 
months, thus making possible, both summer and winter dairying, 
which is an added advantage in plant operation. 

(2). Variations caused by changes in the feed of the cows. — 

Particular reference is made here to the influence of such changes 
upon the components of the milk as affect the coagulating point. 
Relatively little exact information is now available upon this 
subject. It is well known that as soon as cows change from dry 
to green feed, or vice versa, that a change in the coagulating 
point of the milk is at once apparent. 

(3). Variations caused by temperature and other climatic 
changes. — It is well known that immediately following storms, 
the coagulating point of the milk usually decreases several de- 
grees. This has reference to the mixed milk from a large number 
of herds. Part of this decrease may be caused by the increased 
acidity which is usually produced because of the conditions fav- 
orable to acid development that exist at the time of a storm. 
Changes in the temperature itself surrounding the cow, aside from 
other factors, may cause changes in the composition of the milk, 
such as would influeiiee its heat coagulation, but as yet relatively 
little is known upon this subject. 

Fig. 171 illustrates the average of several seasonal variations 
ill the coagulating point of evaporated milk. This refers to 
evaporated milk produced at plants located in the temperate 
zone, where, both summer and winter dairying are practiced. It 
is assuuicd that the eoagnlating points indicated would be those 



Variation in Coagulating Point 



753 



obtained by foreAvarming the milk all alike in the hot wells ; con- 
densing it to the Federal standard of butter fat and total solids ; 
sterilizing it for 15 minutes at the various temperatures indicated, 
and in all cases obtaining a viscosity of 150° retardation. Under 



2lM 



<z 

u:n 
(0 J 
lilac 

(Jul 

Oixl 

?t: 

Ooc 

OO. 



ST 



R 



LIZ 



N6 



EVAP 



RAT[ 



DM 



Lt\ 



i^mi 



l^.M: 



i^UV-\ 



"ANDARD 



TEMPERA 

Urn 



RE 



illlli 



mm 



Tig. 171. Averag-e Seaisonal Variations in the Coagnxlating' Point of 
Evaporated Milk. 



intelligent management, and by applying our acquired knowledge 
the variations indicated can be correctly increased or decreased 
to the standard desired, as the case might require. Granting the 
milk to be of good, normal quality, and all other conditions prop- 
erly standardized except the coagulating point, two general 
methods of control are available as follows : 



754 



E VAPOR ate;d MiIvK 



(1). To raise the coagulating point increase the fore warming 
time and temperature in the hot wells, or add bicarbonate of soda. 
Usually it is necessary to do both. 

(2). To decrease the coagulating point decrease the fore- 
warming time and temperature, or increase the sterilizing 
temperature. It is frequently necessary to do both. 

SOME EFFECTS OF STERILIZING TEMPERATURES UPON THE 
NITROGENOUS CONSTITUENTS OF EVAPORATED MILK. 

Samples were obtained from six different batches each con- 
taining the milk from approximately 100 cows. These samples 
were carefully tested for casein, albumin and total protein, using 
the official methods of analysis as given in Chapter VII. In turn 
samples from the finished product, just after sterilizing, were 
likewise tested for casein (which included the albumin which 
had been coagulated by heat, and which in turn was precipitated 
along with the casein when making the determination of acid 
insoluble protein), albumin and total protein. The percentage 
of the various constituents was shown in Table 143. 

TABLE 143. 
Percentage of Each Protein Constituent. 





Percentage of each Constituent oflthe total Protein Content 


Product 


Casein (including acid- 
insoluble Protein) 


Albumin 


Other 
Protein 


Total 


Fresh milk before heating .... 


Per cent 
77.84 


Per cent 
13.12 


Per cent 
9.04 


Per cent 
100.00 


Evaporated milk after steriliz- 


86.97 


4.12 


8.91 


100.00 







In the above experiments 68,60 per cent of the total albumin 
contained in the fresh milk was precipitated in the evaporated 
milk after sterilizing. In the case of the protein called "other 
protein" only 14.38 per cent was coagulated by the sterilizing 
process. This group includes all the nitrogenous substances ex- 
cepting the casein and albumin, some of which no doubt are not 
members of the protein group. The majority of these substances 
apparently are not affected by the sterilizing temperatures. 

No exact data is available to show what percentage of casein 
itself is coagulated during the sterilizing operation. It must be 



Viscosity 



755 



remembered that only a fraction of the total casein should be 
coagulated, as otherwise the product would not be a salable one. 
Probably in normal evaporated milk of correct viscosity the 
casein coagulated does not exceed ten per cent of the total 
present. In the "acid solution used to determine the total casein, 
the part coagulated by heat, apparently, is all precipitated along 
with that not coagulated by the heat. 

Changes in Viscosity at Various Stages in the Manufacture of 
Evaporated Milk. — The viscosity was determined in eight batches 
of fresh milk before heating, and after heating twice to the 
boiling point, allowing the milk to stand a few minutes between 
the two heating intervals. Upon four of the batches the viscosity 
was determined in the condensed product just as soon as cooled 
after condensing, and finally after sterilizing. In all cases the 
various products were all reduced to equal temperatures before 
determining the viscosity. The average results are given in 
Table 144. 



TABLE 144. 
Viscosity Changes in Products Used to Make Evaporated Milk. 



Name of product and stage in 
process of manufactiure 


No. of 

samples 

tested 


Viscosity at 75° F. in terms 
of degrees of retardation. 


Fresh milk before heating 


8 


15.24 


Fresh milk after heating 


8 


15.26 


After condensing and cooling. 
Before sterilizing. 


4 


20.20 


Evaporated milk just after 
sterilizing 


4 


150.00 



The above results show that there is no practical or measurable 
difference in the viscosity between the fresh milk before and after 
heating in the hot wells when reduced to the same temperature 
and composition basis. The viscosity is only slightly increased 
by condensing, taking into consideration the increased total 
solids. The large gain in viscosity occurs in the sterilizing opera- 
tion. This is closely associated with'the coagulation of the casein 
and albumin. 



756 Evaporated Milk 

VARIATIONS IN VISCOSITY OF EVAPORATED MILK. 

The viscosity of a considerable number of cans of evaporated 
milk, of the same and of different brands as found upon the 
Chicago market was determined by one of the authors® using the 
Mojonnier-Doolittle viscosimeter. The results of these determina- 
tions are given under Fig. 172. 

The viscosity is expressed in terms of degrees of retardation, 
as indicated upon the left hand column. The round spots indicate 
the tests of the respective samples. Where more than one sample 
of the same brand was tested, they are connected with the 
straight lines. A total of fourteen brands was tested, and the 
same are indicated by the number upon the top of Fig. 172. 



• < 4 5 6 7 8 9 10 11 la 13 14 

^^'* ABCABCABABCABCABABABABC^BAar 
220* 




V 

VISCOSITY OF EVAPORATED MILK 

Fig. 172. Viscosity of Evaporated nXilk. 

The above residts indicate a considerable variation in viscos- 
ity in most cases as between both the same and different brands. 
This fact obtained notwithstanding a close agreement in composi- 
tion. The majority of the samples ]i«d a viscosity that was well 
within the ranges that constitute a good commercial product. 
Several of the samples had such excessive viscosity that the 
product would have curdled when added to coffee. Viscosity is 
a physical condition that can be influenced in several ways. 
Shaking the milk will reducfe it. This is purely a mechanical 
result, whereby the large coagulated masses are disintegrated into 



Shaking 757 

smaller particles. Viscosity is also greatly reduced by age, 
especially if the product is stored at a comparatively high temper- 
ature. In this case the change is caused by chemical action the 
nature of which is not understood, but it is probably based upon 
the fact that some substances contained in the milk react upon 
the coagulated casein and albuuiin, and cause them to return into 
solution. 

The Function of Shaking and its Influence Upon the Viscosity 
in the Manufacture of Evaporated Milk.— The practice of shaking 
evaporated milk after sterilizing is as old as the industry. The 
two most common types of evaporated milk shakers are illus- 
trated under Figs. 178 and 174. 




Tig. 173. Fort Wayne Shaker. 

Courtesy The Engineering Co. 

Evaporated milk after sterilizing frequently has a wide range 
of viscosity, especially in plants where the sterilizing operation is 
not carefully standardized. The purpose of the shaking operation 
is to destroy the excess of viscosity over that desired, and to 
reduce it all to certain standard, with the aim of making the 
entire output of the plant of uniform viscosity and of a homo- 
geneous appearance. 

The shaking operation is one of great importance, and one 
that needs to be well understood, and intelligently applied in 
practice. 



758 



Evaporated Mii^k 



The influence of excessive shaking upon the viscosity is shown 
by the following experiment, as given in Table 145. 



TABLE 145. 



No. of 
Samples 


Viscosity after 

Shaking to Correct 

Standard 


Viscosity after it 
Shaking half Minute 
Itoo Much 


Viscosity after 

Shaking Three 

Minutes too Much 


Viscosity after 

Shaking Nine 

Minutes too Much 


2 


SO 


57 


45 


3S 



The above results show plainly how viscosity is destroyed by 
shaking. The higher the temperature of the evaporated milk at 
the time of shaking the more viscosity will be destroyed, and the 
greater will be the danger of excessive shaking. Evaporated milk 
that is very cold is much more difficult to shake properly than 
that at ordinary or at warm temperatures. The best results in 
shaking are obtained and the danger of overshaking is more easily 
avoided if the shaking is done at ordinary temperatures. 




Pigr. 174. Berlin Sliaker. 

Courtesy Bei'lin Canning Machinery Works. 

Influence of Resterilization in Restoring" Lost Viscosity. — ^Vis- 
cosity is a physical property that can be produced, destroyed and 
reproduced in several ways. The simplest method is by re- 
sterilization whereby the milk is subjected to only a fraction of 
the heat applied in the original process. 

The average results of ten careful tests were as follows, in 
terms of degrees of retardation : — 

Viscosity after goods were first finished 80 

Viscosity after destroying part of original vis- 
cosity by shaking, and before resterilizing 30 

Viscosity after resterilizing 64 



Shaking 



759 



The original viscosity was not completely restored, due largely 
to the failure in uot resterilizing the milk at a temperature high 
enough to restore it. 

Influence of Storage Temperatures and of Immediate and Sub- 
sequent Shaking Upon the Viscosity of Evaporated Milk. — The 

handling of evaporated milk after sterilization varies in many 
particulars in practice. When shaking is necessary this is usually 
done soon after the product leaves the sterilizer. Also the 
temperatures at which the milk is handled between the time 
of sterilizing and the time of shipping, as well as between the 
time of shipping and the time when the product reaches the 
consumer, range between wide limits. The plan of holding the 
freshly sterilized product in a so-called hot room is a practice 
that is still being followed. Likewise the shaking is not a 
standardized operation. 

A series of very careful experiments were performed to study 
the influence of the above factors upon the viscosity of evaporated 
milk. The results are given in Table 146. 

TABLE 146. 

Changes in Viscosity of Evaporated Milk Under Different Storage 

Temperatures. 



Storage Conditions 


No. of 
Samples 
Averaged 


Viscositj- in Degrees 
Retardation 


Percentage 

Loss in 

Viscosity 




Before 
Storing 


After 
Storing 


Due to 

Storage 

Temperatures 


In hot room 14 days at 79° F 


S 


80 


63 


20.25 


In hot room 28 days at 79° F 


8 


80 


54 


32.50 


In hot room 110 days at 79° F 


8 


80 


33 


58.75 


In hot room one week, and then at ordinarj- 
temperatures, 69° F. for 7 days 


t» 


80 


68 


15.00 


In hot room one week, and then at ordinary 


8 


80 


60 


25.00 






In hot room one week, and then at ordinary 
temperatures, 69° F. for 103 days 


8 


80 


48 


40.00 


In hot room one week, and then in cold room 
at 45° F. for 7 days 


8 


80 


73 


8.75 






In hot room one week, and then in cold room 
at 45° F. for 21 days 


8 


80 


75 


6.25 






In hot room one week, and then in cold room 
at 45° F. for 103 days 


S 


SO 


71 


11.25 







760 EvAPORATiiD Milk 

The results in Table 146 show clearl}^ the large influence that 
storage temperatures play upon the viscosity of evaporated milk. 
The average percentage loss in viscosity at the end of 110 days 
was as follows : 

When stored at 79° F 58.75 per cent. 

When stored at 69° F 40.00 per cent. 

When stored at 45° F 11.25 per cent. 

The above facts are of great practical significance since viscos- 
ity is so important a factor in the merchandising of evaporated 
milk. 

In view of the fact that evaporated milk loses so much in 
viscosity upon aging unless it is stored at low temperatures the 
most uniform final results can be obtained if the shaking is done 
at the end rather than at the beginning of the storage period. 
The length of the shaking period can be reduced to allow for 
the viscosity that was destroyed due to storage influences. 

THE DETECTION OF SPOILS IN EVAPORATED MILK. 

Spoilage that develops in evaporated milk after condensing 
and before sterilizing is caused almost entirely by the use of too 
high holding temperatures. Evaporated milk that is to be 
promptly sterilized after filling the same day that is is condensed 
should be cooled to at least 60° F. When held for 24 hours it 
should be cooled to 44° F. For 48 hours to 40° F. It is never 
advisable to hold it more than 48 hours between the time of 
condensing and the time of sterilizing, but if this should ever 
be necessary the holding temperature should be reduced to about 
34° F. 

Spoilage after sterilizing evaporated milk divides itself into 
three main classes as follows : — 

(1). Spoilage due to leaky cans. — This is caused by defective 
tin plate, or by improper soldering of the seams. Spoilage of 
this kind is almost invariably attended with lactic acid develop- 
ment and it can be thus readily recognized. It is universally 
recognized that the optimum temperature of growth of the 
great majority of lactic acid is about 68° F. Large leaks will 
manifest themselves in from 24 to 48 hours at room temperatures. 
Minute pin holes, that can be detected with the naked eye only 
with great difficulty, will show spoilage only after a considerably 



vSpOILACIt 761 

longer time regardless of whether the storage temperature is 68 or 
97"^ F, When the cans used are manufactured by a responsible 
concern, and if the same are well sealed after filling, the spoilage 
due to defective cans may be reduced to a minimum, and it should 
not exceed two cans per 1000 packed. 

Granting that the can supply is of high quality, spoilage due 
to leaky cans is most readily detected if the sterilized product 
is kept at room temperatures. Nothing can be gained in helping 
to develop spoilage if higher storage temperatures are used. 

(2). Spoilage due to under-sterilization. — This is caused by 
errors in processing, or by the use of unsafe sterilizing records. 
At the present state of knowledge of this science, spoilage losses 
due to under-sterilization are completely avoidable. By following 
the recommendations contained in this chapter, losses due to 
under-sterilization. barring accidents, can be completely pre- 
vented. 

Spoilage of this kind manifests itself at ordinary temperatures 
in from four to seven day after the sterilizing operation. The 
use of higher storage temperatures will not, as a rule, expedite 
spoilage of this nature. 

(3). Spoilage due to all other causes. — None of these are 
influenced by the temperatures at which the sterilized milk is 
held. Included under this heading can be mentioned a number 
of kinds of spoilage occasionally encountered. Coagulated lumps 
or balls of casein— this is usually due to the presence of zinc 
chloride flux inside of the can. Coagulated specks or masses of 
casein scattered more or less throughout the entire can — this is 
caused by improper shaking ; uneven or excessive sterilization, 
and improper methods of forewarming the milk in the hot wells. 
Fatty separation sometimes develops after the milk has aged — 
this is due to the improper homogenization of the unsterilized 
product. With the homogenizer in good condition, and under 
operating pressures of 2000 to 3000 pounds, spoilage of this 
nature should be completely avoided. 

FACTORS THAT INFLUENCE THE QUALITY OF EVAPORATED 

MILK. 

The separation of calcium citrate in evaporated milk. — After 
evaporated milk has aged for a considerable time there appears 



762 Evaporated Mii,k 

upon the bottom of the cans, white, gritty sand-like particles, 
M^hieli are lime salts of citric acid or tricalcium citrate, Ca^. 
(CcH567)2+4HoO. It is more easily soluble in cold than in hot 
water; and it, therefore, precipitates from dilute, boiling solu- 
tions. Much remains to be learned regarding this substance in 
milk, and many conflicting statements regarding it appear in the 
literature. It is illustrated under Fig. 175. 




Pig". 175. Calcium Citrate Taken Prom Cans of Evaporated Milk. 



A sample of unheated skim-milk was condensed over sulphuric 
acid about three volumes into one volume, without applying anj^ 
heat. A lump of thymol was added, and the condensed product 
sealed and stored at about 85° F. for about three months. A 
considerable amount of calcium citrate was found deposited upon 
the bottom of the container at the end of the observation period. 
This proves that the separation of the calcium citrate is inde- 
pendent of the temperature used in sterilizing. 

There are several factors that influence the separation of 
calcium citrate in evaporated milk. The principal ones are as 
follows : 

(1). Variations in the calcium and citric acid content of 
milk. — It is well established that both calcium and citric acid 
(probably all combined with a base) vary in their content in milk 



I 



Calcium Citrate 763 

between relatively wide limits. The increase in mineral con- 
stituents is especially marked as the period of lactation advances. 
This is one explanation as to why the deposits of calcium citrate 
in evaporated milk cans vary so much, there being considerable 
differences in the total quantities found in different cans of very 
similar total solids content. 

(2). Degree of condensation. — Obviously the larger the 
amount of total solids, especially milk solids not fat, the greater 
will be the quantity of lime salts available for separation. This 
is a strong argument in favor of a reasonable total solids standard. 

(3). Storage temperatures. — The separation of lime salts in 
evaporated milk under dift'erent temperatures of storage was 
very carefully studied. Twenty seven samples were kept under 
observation for about four months. Evaporated milk stored at 
about 85° F. for one month or more, showed large amounts of 
fine particles and many large particles of grit. At about 68° F. 
at the end of from 78 to 110 days there was a considerable amount 
of large particles. At 45° F. there was no separation whatever 
at the end of four months. The above findings are in keeping 
with the fact that the solubility of calcium citrate decreases as 
the temperature increases. After precipitation has once occurred 
the particles do not return into solution even when the tempera- 
ture is dropped under the usual conditions of handling. The 
product usually reaches the consumer with the largest part of 
the calcium citrate that separated out at any time still present 
in it. 

(4). Affect of viscosity. — This factor was also studied by 
means of many careful experiments. Viscosity was found to have 
no effect upon the separation of calcium citrate in evaporated 
milk stored at 45° F. or less. Samples from the same batch in 
which the viscosity had been reduced about 57 per cent by exces- 
sive shaking were as free from precipitation at the end of four 
months as the samples which had not been shaken, and which 
contained excessive viscosity. Upon the other hand, samples of 
evaporated milk which had been stored at either 68° of 85° F., 
in all cases those samples which possessed the lowest viscosity 
were the ones which showed the most separation. The lower 
viscosity apparently favored the growth of the particles. 



764 Evaporated Milk 

It follows from the above that the temperature of storage is 
one of the most important factors controlling the separation of 
calcium citrate. The higher the storage temperature the more 
will separate or vice versa. 

FACTORS THAT INFLUENCE COLOR IN EVAPORATED MILK. 

The color of evaporated milk is important as affecting its 
commercial value. Too little color is usually a sign of under- 
sterilization. Too much color may greatly impair its commercial 
value. The principal factors that influence color are the 
following : — 

(1). The color of the fresh milk.— The color of fresh milk is 
normally subject to many fluctuations throughout the course of 
a year. Palmer and Eckles^" have proved that this is due to 
distinct pigments dissolved in both the milk fat and in the milk 
serum. The pigments causing coloration in the fat, are the same 
as those found in green plants, and are known as carotin and 
xanthophylls, and their presence in milk is due to the fact of 
their absorption in the body of the cow, and their subsequent 
secretion in the milk. The coloration of the milk fat is largely a 
feed characteristic. 

The pigment causing coloration of the milk serum is known 
as lactochrome, and its general characteristics are identical to 
the pigment contained in normal urine. The researches of Palmer 
and Coolidge^^ prove this to be a breed characteristic — the milk 
of Jerseys and Ayrshires containing it much more abundantly 
than that of Shorthorns or Holsteins. 

The coloration due to the milk fat is by far the more important. 
In the manufacture of evaporated milk it is during the spring 
and summer months that the color of the finished product is 
increased because of the color of the fresh milk. The sterilizing 
time should be kept at a minimum, and the cooling promptly 
finished in the sterilizers. 

(2). Concentration. — The more the fresh milk is condensed, 
the more color the freshly condensed product will contain. The 
increase in color due to concentration is very slight. 

(3). Sterilization. — The sterilization process exei-ts a great 
influence upon the color of evaporated milk. The higher the 



Acidity 



765 



temperature and the longer the time, the greater will be the color. 
The increase in color is due to the action of the heat upon both 
the protein and the milk sugar. The exact changes that occur 
are not clearly understood at present. 

(4). Storage temperatures. — In careful experiments it was 
ascertained that evaporated milk stored at 85° F. increased in 
color very rapidl}^ and very greatly. At the end of four months 
at 68° F. there was also a marked increase in color, while at the 
end of the same tirae at 45° F. the increase in color was very much 
less marked. A satisfactory color can therefore be maintained 
much longer if the evaporated milk is stored at a low temperature. 

The Titratable Acidity in the Various Stages of the Manu- 
facture of Evaporated Milk. — The acid content as measured in 
terms of titratable acidity varies in several interesting particulars 
in all stages of the manufacture of evaporated milk. The cause of 
these changes are not fully understood. The average results of 
13 very careful tests are given in Table 147. 

TABLE 147. 
Titratable Acidity in Evaporated Milk at Various Stages. Average Results. 



Name of product 


Percentage of 

titratable 

acidity 


In fresh milk before heating .- 


.14 






In fresh milk after heating in the hot wells 


.13 






'in freshly evaporated milk before sterilizing 


.32 






In evaporated milk after sterilizng 


.39 






In evaporated milk after storing for four months at 45° F. 


.39 


In evaporated milk after storing for four months at 68° F. 


.40 


In evapoi'ated milk after storing for four months at 85° F. 


.43 


In evaporated milk after storing for one year at room 
temperatures 


.45 






In evaporated milk after storing for two years at room 
temperatures 


.50 






In evaporated milk after storing for three years at room 
temperatures 


.55 







766 Evaporated Milk 

As the above typical results show, there is first a decrease in 
titratable acidity upon forewarming the milk in the hot wells. In 
the evaporated product there is a gradual increase at every stage. 
High storage temperatures are especially favorable to the pro- 
duction of an increase in the titratable acidity. Dr. H. S. Grindley 
and his associates at the University of Illinois in their researches 
upon the cooking of meat proved that the coagulation of the 
protein constituents of meat by heat is accompanied by a con- 
siderable increase in the titratable acidity. In the case of 
evaporated milk an increase in titratable acidity during the 
sterilizing process is no doubt closely associated with the coagu- 
lation of the protein constituents. Why the acidity should 
increase with age, or the kind of acidity that is produced under 
the conditions named, are both unsolved problems. 

The Influence of Freezing Temperatures Upon Evaporated 
Milk. — It occasionally happens that during transportation or in 
warehouses evaporated milk becomes frozen. A careful experi- 
ment was made to determine the effect of freezing. Duplicate 
samples from fourteen different batches of evaporated milk were 
taken. In one set the viscosity was determined at once. The 
second set was kept frozen continuously for sixteen days and 
nights, at temperatures ranging from 10 to 34° F. The samples 
were then kept at room temperature of about 69° F. for twenty- 
two days, at which time they were tested for viscosity and their 
physical condition carefully examined. 

The average viscosity before freezing was 80° retardation. 
After freezing and thawing as above it was 81° retardation, show- 
ing practically no change in viscosity. 

There were no traces of fat separation, but all the cans con- 
tained small amounts of brownish watery separation upon their 
bottoms. This watery part was readily reincorporated upon 
shaking the can. The texture of the milk was normal in all 
respects. Evaporated milk which has been frozen if handled 
as described in the above experiment can be restored to a com- 
pletely normal condition, without loss or detriment. 



Viscosity 767 

VISCOSITY AS RELATED TO THE FEATHERING OR CURDLING 
OF EVAPORATED MILK IN COFFEE. 

The practice of adding evaporated milk to coffee to study its 
solubility in the latter is an old one. The conclusion usually 
reached being that if the milk curdles, either the milk has too 
much acidity, or that something is wrong with the coffee itself. 
Upon the other hand, if the milk dissolves smoothly in the coffee, 
it is assumed that the milk does not contain an excess of acid and 
that nothing is wrong with the coffee. 

The following experiment was made to establish the exact 
facts in the case. Samples were taken from each of two batches 
of evaporated milk. The samples from both batches varied 
greatly in viscosity. This was owing in part to the fact that the 
sterilizer in which these samples had been sterilized did not 
cook the milk uniformly, due to one of the end plugs being 
out of one of the steam distributing pipes, and also to the fact 
that some of the samples were purposely shaken in order to 
reduce the viscosity thereof. Batch No. A tested 7.99 per cent 
butter fat and 26.26 per cent total solids. Batch No. B tested 
7.89 per cent butter fat and 25.65 per cent total solids. 

The viscosity was determined upon each can by means of the 
viscosimeter illustrated under Fig. 140. The viscosity is ex- 
pressed in degrees of retardation as indicated upon the dial which 
is graduated from to 360. The greater the viscosity, the larger 
numerically is the degree of retardation. 

Three cups were filled with hot coffee, hot water and cold 
water respectively. The spoonful of milk from each sample was 
added in turn to each cup. The results obtained are given in 
the following table. 

The following conclusions are drawn from the above ex- 
periment : — 

1. Hot coffee has no merit over cold or hot water as far as 
indicating the tendencj^ of evaporated milk to curdle. The 
amount of curd formed was practically alike in all cases. 

2. The formation of curd when evaporated milk is added to 
coffee is due entirely to an excess of viscosity. In the same and in 
different samples of evaporated milk where all factors were alike 
excepting viscosity, the tendency to curdle was always evident 
in the presence of excessive viscosity. 



768 



FvVAPORATKD MlT.K 



TABLE 148. 
Comparison of Cuidling Effect of Coffee and of Water on Evaporated Milk. 



Date 


Batch 
No. 


Sample 
No. 


Viscosity 
at 75° F. 
retarda- 
tion 


Results after adding one tablespoonful 
evaporated milk to 1 pint:— 


REMARKS 


Hot coffee 


Hot water 


Cold water 




2-24-19... 

2-24-19... 

2-24-19... 

2-24-19... 

2-25-19... 

2-25-19... 

2-25-19... 
2-25-19... 

2-25-19... 


A 

A 

A 

A 

B 

B 

B 
B 

B 


1 

3 
4 
5 
6 

8 
9 


173 
59 
68 
70 
53 

201 

117 

84 

15 


Curdled badly 

No curd 

No curd 

No curd 

No curd 

Curdled badly 

Curdledlslightly 
No curd 

No curd 


Curdled badly 

No curd 

No curd 

No curd 

No'curd 

Curdled badly 

Curdled slightly 
No curd 

No curd 


Curdled badly 

No curd 

No curd 

No curd 

No curd 

ICurdled badly 

Curdled slightly 
No.curd 

No curd 


Heavy viscosity 

from sterilizer. 
Light viscosity 

from sterilizer. 
Light viscosity 

from sterilizer. 
Shook to reduce 

viscosity. 
Light viscosity 

from sterilizer. 
Heavy viscosity 

from sterilizer. 
Shook slightly. 
Shook just right 

amount. 
Not sterilized. 



3. The tendency to curdle can be entirely prevented by 
destroying the excess of viscosity by shaking the evaporated milk 
in the cans after sterilizing. 

Influence of the Method of Cooling Upon the Color and Vis- 
cosity of Evaporated Milk. — The method of cooling employed at 
the sterilizers at the end of the sterilizing operation is most 
important as affecting the physical properties of the finished prod- 
uct. When water is used in the sterilizers a standard method 
should be followed in forcing the water out of the sterilizer at 
the end of the run. If the sterilizer outlets are sufficiently large 
the water should be all forced out within two or three minutes 
after shutting off the steam. The cooling water should be turned 
on as soon as the hot water is all out, or within two or three 
minutes after the steam has been turned off. When steam only 
is used, the cooling water should be turned on the instant that 
the steam is turned off. The hot water produced during the first 
stage of the cooling period should be allowed to run immediately 
into the sewer. The sewer valve can be closed after about five 
minutes, and the cooling completed in a total of about fifteen 
minutes, or until the milk attains a temperature of about 75° F. 

The influence of the method of cooling as studied by careful 
experiments. Samples from the batch immediately after steril- 



COOIJNG 



769 



izing were cooled as indicated in Table 149. The color and the 
viscosity were noted in all cases. 

TABLE 149. 
Color and Viscosity of Evaporated Milk Under Different Methods of Cooling. 



Number of 
batches 
tested 


Method of cooling 


Average color at 
75° F. 


Average viscosity 
at 75° F. re- 
tardation 


9 


Cooled in 6 to 10 min- 
utes to 52° to 59° F. 


Excellent color 


80 


9 


Cooled in 20 to 25 
minutes to 92° to 
142° F. 


Color much darker 
than above 


70 



The above results prove that slow and incomplete cooling in 
the sterilizers greatly increases the color. Batches that show 
excessive viscosity when sterilized may be further damaged by 
incomplete cooling, since they will take much longer to air-cool 
than the batches that are of low or of proper viscosity. This is 
due to the fact that coagulated milk is a poor conductor of heat. 

The small differences in viscosity were in favor of the milk 
which had been rapidly cooled. In the majority of cases this 
difference was still apparent after the goods had been kept in 
storage for about four months. 

GASES IN EVAPORATED MILK CANS. ' 

Baker^- studied the gases in the air space of hermetically 
sealed cans containing various sterilized foods including evapo- 
rated milk. He never found more than three gases, — "Carbon 
dioxide, nitrogen and hydrogen. Very often no hydrogen is 
found. Oxygen is practically never found. Changes in tempera- 
ture of these cans produce changes in gas pressure. At 85° F. 
we may have a well puft'ed can, at 60° F. one in which there is 
practically no pressure, and at 45 to 50° there will be a vacuum. 
These changes occur with a decrease of temperature because the 
gas itself contracts, the solid and liquid contents of the can 
contracts and the solubility of the gas increases." 



770 



Evaporate;d Mii.k 



"The oxygen disappears in at least the three following man- 
ners. (1). By combining with the metals forming tin and iron 
oxides. (2). By oxidizing tin or iron salts. (3). By combining 
with nascent hydrogen when organic acids act on the metallic 
container." It is also probable that oxygen combines directly 
with the fat contained in evaporated milk, and some of it may be 
taken up during the carmelizing that occurs when processing 
evaporated milk. 

The solubility of carbon dioxide at various temperatures is 
shown in Table 150.'° This has an interesting application in con- 
nection with evaporated milk, whenever sodium bicarbonate is 
added to reduce the coagulating point. The more carbon dioxide 
that may be contained in the milk, the greater will be the danger 
from bulged can ends, especially during the summer months. 

TABLE 150. 

Solubility of CO, in Water. 1 Volume H^O at T° and 760 mm. Dissolves 

V Volumes CO- Gas Reduced to 0° and 760 mm. 



T" 


v 


T" 


V 


T° 




C 


F 


C 


F 


C 


F 


V 





32 


1 . 7967 


7 


44.6 


1 . 3339 


14 


57.2 


1.0321 


1 


33.8 


1.7207 


8 


46.4 


1.2809 


15 


59.0 


1.0020 


2 


35.6 


1.6481 


9 


48.2 


1.2311 


16 


60.8 


0.9753 


3 


37.4 


1 . 5787 


10 


50.0 


1.1847 


17 


62.6 


.9519 


4 


39.2 


1.5126 


11 


51.8 


1.1416 


18 


64.4 


.9318 


5 


41.0 


1.4497 


12 


53.6 


1.1018 


19 


66.2 


.9150 


6 


42.8 


1.3901 


13 


55.4 


1.0653 


20 


68.0 


.9014 



References 771 

REFERENCES. 

1 Rice, P. E. Abstract of paper on apparent acidity of milk. Science new 
series, Vol. L., No. 1296, October, 1919. 

2 Sommer, H. H, and Hart, E. B. The heat coagulation of milk. Journal 
of Biolog-ical Chemistry, Vol. XL., 1919, pp. 137 and 152, 

« Mclnerney, T. J. Jour, of Dairy Science, Vol. 3, 1920, p. 220. 

* Hunziker, O. F. Purdue University, Bui. 143, Vol. XV., May, 1910. 
^ Mojonnier, T. 

8 Hunziker, O. F. Purdue University, Bui. 143, Vol. XV., May, 1910, p. 489. 
^ Rogers, L. A. The Canner. March 5, 1921, p. 165. 

* Latzer, R. L. The Effect of Pasteurization and Sterilization on the Solu- 
bility of Milk Proteids. Thesis, Department of Agricultural Chemistry, Cor- 
nell University. 

8 Mojonnier, T. Controlling the Chemical and Physical Properties of 
Evaporated Milk. The Canner, Convention number, 1917. 

" Palmer, Leroy S, and Eckles, C. H. Carolin, the principal natural yel- 
low pigment of milk fat, its relation to plant carotin and the carotin of body 
fat corpus luteum and blood serum. Jour. Biol. Chem., Vol. 17, 1914, p. 191. 

'^i Palmer, Leroy S. and Coolidge, Leslie H. Lactochrome, the yellow pig- 
ment of milk whey, its probable identity with urochrome, the specific yellow 
pigment of normal urine. Jour. Biol. Chem., Vol. 17, 1914, p. 251. 

12 Baker, H. A. 8th International Cong. App. Chem., Vol. 18, pp. 35 and 49. 
'"Bunsen's Gasometry, pp. 289 and 141. 



CHAPTER XX 
SCORE CARDS FOR THE DAIRY INDUSTRY 

INTRODUCTION. 

For a number of years it has been customary in judging 
butter and cheese to print on a card the factors that contribute 
towards quality in these products and to give a numerical val- 
ue to each factor. The cards also contain space for other neces- 
sary data, and are called score cards. They have contributed 
toward systematic Avork in scoring and help to bring into prom- 
inence the factors that control quality. In this way score cards 
have been of considerable educational value. They also form 
a concise record that may be filed for reference. 

The score cards are now also used in judging milk, cream, 
and to a limited extent ice cream, and they have been applied to 
the scoring of dairies and market milk plants. Their proven 
merit make it appear that they will be of similar value in judging 
all the other newer milk derivatives. Examples of score cards 
now in use are given in this chapter and others are devised 
for use in scoring products where they have not heretofore been 
applied. 

DEVELOPMENT OF THE DAIRY SCORE CARD. 

MILK : The first public attention given to the quality of 
milk in this country was in reference to its chemical composition. 
It resulted in the enactment of laws against adulteration, the 
first of which was passed by the state of Massachusetts in 1856^ 
Other states later enacted similar legislation and systems of in- 
spection were developed and laws enforced. When the science 
of bacteriology demonstrated that disease was largely due to 
pathogenic organisms and that milk, if not properly safe-guarded, 
might serve as a carrier of them, regulations controlling the san- 
itary quality of milk during its production and distribution were 

[772] 



Milk Inspe;ction TIZ 

developed and enforced by state and local communities, espe- 
cially the larger cities. 

The enforcement of these regulations was difficult when the 
work was in the period of development and few persons were 
properly trained to serve as efficient inspectors. Fortunately 
from the beginning, the methods of enforcement aimed to be 
educational and constructive, rather than arbitrary and oppres- 
sive. 

The leaders in dairy schools and officials responsible for the 
enforcement of regulations established by Boards of Health, soon 
recognized the need of a synopsis of the salient points that 
govern the sanitary production and distribution of milk. Much 
thought and study was given to the development of such an 
outline which finally resulted in bringing forth the dairy score 
card. 

The score card for the dairy is a systematic arrangement 
and rating of the points and conditions of importance in the pro- 
duction of clean milk. It is detailed in character giving credit 
to each condition according to its merit, a total score of 100 in- 
dicating perfect. 

In making an inspection it is sometimes preferable to record 
on a question sheet the data necessary for determining the score. 
The inspector may then make out the score card from the record 
on the inspection sheet after returning to his office. The use of 
this method assists in avoiding arguments with proprietors Avho 
may be inclined to take exceptions to the score allowed when 
it is recorded in their presence. 

The following milk inspection question sheet used by the 
Department of Dairy Industry of the New York State College 
of Agriculture, and score cards from other sources, for the farm 
dairy and milk distributing plants serve as illustrations. 

New York State College of Agriculture at Cornell University 
DEPARTMENT OF DAIRY INDUSTRY 



MILK INSPECTION QUESTION SHEET. 



Dairyman Date. 

P. O Location 



774 Score Cards 

No. cows in herd Milking No. stalls Qts. milk Cans or bottles 

Name of family physician 

]\Iilk sold to License No. 

Report by At milking time? Hour M. 

EQUIPMENT. 

I. Cows. 

Do all cows appear healthy? 

What signs are there of disease? 

Are udders sound? 

Are cows tuberculin tested? 

Date of last test By whom tested? 

Number of cows added to herd since last test 

(Roughage 

Kinds of feeds used, ^Concentrates 

Are tliey of good quality? 

Method of watering Cleanliness of trough and surroundings 

Is water supply abundant? 

II. Stables. 

Is stable well located? 

Construction of ceiling.... Walls.. ..Are ceiling and walls smooth and tight? 

Construction of Hoor State of repair 

Size of stable, length Width Height 

Size of stall, length Width 

Kind of stanchion Kind of mangers 

Kind of bedding used 

Cubic feet of air space per cow 

Number and size of windows 

Are windows hinged or sliding? 

Distribution of light Sq. feet of light per cow 

How is stable ventilated ? 

Any special provision for controlling temperature? 



Milk Inspection 775 

III. Utensils. 

Are all utensils well constructed and comparatively easy to clean? 

Kind of milk pail used 

Is any cooler used? Kind? 

Are there any facilities for sterilizing utensils? 

What are they? 

Where are they? 

IV. Milk Room or Milk House. 

Location 

Is milk house near any source of contamination, such as pig sty, privy?.. 

Is milk house well drained? 

Construction, Floor Walls Ceiling 

State of repair 

Is house well lighted? Ventilated? 

Are windows provided with screens? 

Are there separate rooms for handling milk and washing utensils? 



METHOD. 
Cows. 

Where are cows kept when sick? 

Are cows free from dirt? 

How are cows cleaned? 

How often are cows cleaned? 

How long before milking are cows cleaned? 

Are udders waslied or wiped with damp cloth before milking?. 
Are udders and flank clipped? How often? 



II. Stable. 

Is stable clean? 

Is there dust or cobwebs on ceiling? Ledges? 

Is there old dried manure on floor?.... Walls?.... Mangers or partitions?. 

Is stable whitewashed? How often? 

Is stable air free from dust and dirt? 

Is stable free from flies? 



776 Score Cards 



Is feeding done before or after milking? 

Has the stable any bad odors? 

No. and kind of other animals in stablo 

Is bedding clean? 

Is barnyard clean? Well drained 

How often is manure removed from stable? 

How far is manure removed from stable? 

Is pasture free from mud-holes or stagnant water?. 

III. Milk Room. 

Is milk room clean? 

Has it any bad odors? 



IV. Utensils and Milking. 

Are utensils clean ? Sterilized ? How ?. 

How are utensils cared for after milking? 

Are milkers healthy? 

Do they milk with clean, dry hands? 

Do they wear special over-all suits? 

How often are suits washed? 

Where are suits kept when not in use? 

Is stable floor dampened before milking? 



Handling the Milk. 

Where is milk strained? 

Are attendants in milk room clean? 

Is milk room free from flies? 

What kind of a strainer is used? 

How soon after milking is milk cooled 

To how low a temperature is milk cooled? 

To how low a temperature is milk stored? 

How is milk protected during transportation to market?. 



Mii.K Inspection 
SCORE 



m 





SCORE 




SCORE 


EQUIPMENT 




METHODS 






Perfect 


Allswed 




Perfect 


Allowed 


cows 






cows 






Health 


6 






■ a 




Apparently in good health . . i 


(Free from visible dirt, 6) 




If tested with tuberculin with 












in a year and no tuberculo- 






STABLE 






sis is found, or if tested with- 












in six months and all react- 






Cleanliness of stable 


f, 




ing animals removed . . . .5 






Floor 2 






(If tested within a year and 


Walls -. I 




reacting animals are found and 














removed, 3.) 






Ceiling and ledges 1 






Food clean and wholesome . . . 


I 




Mangers and partitions . . . .1 






Water, clean and fresh 


I 




Windows 1 






STABLES 






Stable air at milking time . . . . 


5 


._. . 


Location of stable 


2 




Freedom from dust . , 3 






Well drained i 






Freedom from odors 2 






Free from contaminating sur- 












roundings I 






Cleanliness of bedding 


I 




Construction of stable 


4 




Barnyard > 


2 




Tight, sound floor and proper 






Clean i 






, gutter 2 






Well drained . .' i 






Smooth, tight walls and ceil- 






ing I 






Removal of manure daily .... 






Proper stall, tie, and manger . i 






To 50 feet or more from 












stable. 






of glass per cow 


4 




MILK ROOM on, MILK HOUSE 






(Three sq. ft., 3 • s sq. ft.. 2 ; i 






Cleanliness of milk room .... 






.sq. ft., I. Deduct for uneven dis- 
tribution.) 
















UTENSILS AND MILKING 








I 




Care and cleanliness of utensils . 


8 




Ventilation 




Provision for fresh air, control- 






Thoroughly washed . . . . 2 






lable flue system 3 

(Windows hinged at bodom. 






Sterilized in steam for 15 




















( Placed over steam jet or scald- 






openings .50). 






ed with boiling water, 2.) 






Cubic feet«of space per cow, 






Protected from contamination . 3 






500 feet 3 






Cleanliness of milking 


9 





(l,e.ss than 500 ft., 2 ; less than 










400 ft., 1 ; less than 300 ft , 0). 






Clean, dry hands 3 






■ Provision for controlling tem- 






Udders washed and wiped . .6 










(Udders cleaned with moist 
cloth, 4; cleaned with dry cloth 










UTENSILS 






or brush at least 15 minutes be- 
fore milking, i.) 






Construction and condition of 


















HANDLING THE MILK 






Water (or cleaning 










ant.) 

Small-top milking pail ....... 






room 


2 




5 




Milk removed immediately from 
stable without poiiring Jrom pail 


2 






1 




Cooled immediately after milk- 










Clean milking suits 


I 






2 

5 




MILK ROOM, OR MILK HOUSE 


Cooled below 50° F 










(5'° to 55°, 4 ; 56° to 60°, 2.) 






Location free from contamiiut- 






Stored below 50° F 

(51° to 55°, 2 f 56° to 60°, I.) 


3 






1 






Construction of milk room . . . 












Floor, walls and ceiling . . . ,1 












Light, ventilation, screetfs . . i 
Separate rooms for washing 






Transportation below 50° F. . . 
(5>° to 55°. 1-50 ; 56° to 60°, I.) 


2 




utensils and handling milk . . 


I 




(If delivered twice a day atlow 






Facilities for steam (Hot wa» 
lero.5) 


I 




perfect score for storage and 
transportation.) 

Total . . . . . . 








40 




60 





Equipment + Methods. 



-Final Score 



Note i— If any exceptionally filthy condition is found, particularly dirty utensils, the total score may be 
further limited. 

Note 2— If the water is exposed to dangerous contamination, or there is evidence of the presence of a 
dangerous disease in animals or attendants, the score shall be o. 



7J^ Score Cards 

ITHACA BOARD OF HEALTH 



SANITARY INSPECTION OF DAIRY FARMS 



MARKET MILK PRODUCTION 



SCORE CARD 

Indorsed by the Official Dairy Instructors' Association. 

Owner or lessee of farm 

P. 0. address State 

Total number of cows Number milking 

Gallons of milk produced daily 

Product is sold by producer to families, hotels, restaurants, stores, 

to dealer 

For milk supply of 

Permit No Date of inspection 192 

Remarks: 



(Signed) 

Inspector 



Dairy Farms 



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780 ScoRR Cards 

VETERINARIAN'S SCORE 

Date 

Producer Phone.. 

Address 

Total number Cows 

Number Milking 

Number not Milking Cause.. 

Number Tuberculin Tested Date 



General Conditions 



Coat 

Flesh 

Attitude. 



Respiratory System — 

Cough 

Respiration 

Percussion 

Auscultation .'. 

Lymphatic System 

Udder 

Animal has symptoms suspicious of. 
Remarks 



Rating of Herd — E.xcellent, Good, Fair, Poor. 

Signed Veterinarian. 



Milk Plants 781 

UNITED STATES DEPARTMENT OF AGRICULTURE 

BUREAU OF ANIMAL INDUSTRY 

DAIRY DIVISION 

SANITARY INSPECTION OF CITY MILK PLANTS 

SCORE CARD 



Owner or manager 

Street and No. , 

City State. 

Trade name 



Number of wagons Gallons sold daily 

Permit or License No. 



Milk 

Cream. 



Date of inspection '. , 192. 

Remarks: ; 



, Inspector. 

D. D. 331.— 10-8-15 — 5,000. 

8—2475 [OVER] 



782 



Score Cards 



EQUIPMENT 



Building: 
Location: Free from contaminating 
surroundings .■ 



Arrangement 

Separate receiving room 1 

Separate handling room 2 

Separate wash room 1 

Separate sales room 1 

Separate boiler room 1 

Separate refrigerator room 1 

Construction 

Floors tight, sound, cleanable. . . 2 
Walls tight, smooth, cleanable... 1 
CeUingssmooth, tight, cleanable. 1 

Drainage 2 

Floors 1 

Sewer or septic tank 1 

Provision for Ught 2 

(10 per cent of floor space.) 

Provision for pure air 2 

Screens 1 

Minimum of shafting, pulleys, 

hangers, exposed pipes, etc 1 

Apparatus 

BoUer 2 

(Water heater, 1.) 
Appliances for cleansing utensils 

and bottles 2 

Sterilizers for bottles, etc 2 

Bottling machine 1 

Capping machine 1 

Wash bowl, soap, and towel in 

handling room 1 

Condition — .-6 

Milk-handling machinery 3 

Pipes, couplings, and pumps. . 2 

Cans 1 

Labobatory and equipment 



Per- 
fect. 



Water supply , 

Clean and fresh 1 

Convenient and abundant 1 



Total. 



Al- 
lowed. 



B UILDING 

Cleanliness: 

Floors 3 

Walls 2 

Ceilings 2 

Doors and windows 1 

Shafting, pulleys, pipes, etc 1 

Freedom from odors 2 

Freedom from flies 3 

Apparatus 

Cleanliness: 
Thoroughly washed and rinsed.. 3 
Milk-handling machinery ... 2 

Pipes, cans, etc 1 

SteriUzed with live steam 3 

Milk-handling machinery .. . 2 

Pijies, cans, etc 1 

Protected from contamination. . . 1 

Bottles 

Thoroughly washed and rinsed — 3 
SteriUzed with steam 15 minutes. . 3 

Inverted in clean place 1 

Handling mtt.k 

Eeceived below 50° F 3 

(SO" to 55°, 2.) 
(55° to 60°, '1.) 

Rapidity of handling 2 

Freedom from undue exposure to 

air 2 

Cooling 5 

Promptness 2 

Below 45°F.. 3 

(45° to 50°, 1.) 

Capping bot ties by machine 2 

Bottle top protected by cover — .1 

Storage; below 45° F 4 

(45° to 50°, 3; 50° to 55°, 1.) 

Protection during delivery „.. 2 

(Iced in summer.) 

Bottle caps sterilized 1 

Inspection 

Bacteriological work 3 

Insi)ection of dairies supplying 

milk 3 

(2 times a year, 2; once a year, 1.) 

Miscellaneous 

Cleanliness of attendants 2 

(Personal cleanliness, 1; clean, 
washable clothing, 1.) 
Cleanliness of deUvery outfit 2 



SCORE. 



Per- 
fect. 



Total. 



Al- 
lowed. 



Score lor equipment.— plus score for methods equals Total Score 

jjoTE If the conditions in any particular are so exceptionally bad ^s to be inadequately expressed by a score of 

•>0" the inspector can make a deduction from the total score. ft— 2475 



Stores 



783 



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784 Score Cards 

THE SCORE CARD FOR DAIRY PRODUCTS. 

The score card for dairy products aims to give an orderly 
arrangement of the points which a good product possesses. It 
places a numerical value on each point and allows space for re- 
cording the grade assigned in scoring each point. There is also 
provided space for the name and address of the producer or ex- 
hibitor, necessary dates, name of inspector or judge and remarks. 

The advantages of a good score card are (1) its educational 
feature, (2) its influence toward improving quality, (3) it is an 
orderly record that may be filed for reference, (4) it tendR to 
eliminate error. 

In marketing and manufacturing, the score of a product in it 
self is usually of prime importance since it is a large factor in 
fixing the market or price value. The score card here serves as 
a record that gives in mathematical terms the credits allowed on 
each factor that influences value. This record may be of con- 
siderable importance when studied for the purpose of improving 
quality, when used as a basis for trading, and in settling disputes 
as to quality. 

The sanitary quality of milk is the most important factor 
affecting its value, as milk cannot be used as a food if it con- 
tains pathogenic organisms or filth. Its chemical composition 
comes next in importance as it governs the nutrient value. Taste 
and odor come next in order, with color, appearance and other 
details last. The following score card illustrates the arrange- 
ment of points and method of assigning credits for retail bottled 
milk. 

Certified milk: The scoring of certified milk is carried out in 
essentially the same manner as in the case of market milk, but 
the bacteria count is limited to a narrower range and credits as- 
signed accordingly. Also any special guarantees in regard to 
composition must be recognized and the container should comply 
with the regulations for certified milk. 



Milk 785 

UNITED STATES DEPARTMENT OF AGRICULTURE, 



BUREAU OF ANIMAL INDUSTRY, 
DAIRY DIVISION. 



sc 

Plar.p. 


ORE CARD FOR MILK. 




Class 1 


Ixhihit J^o 




ITEM. 


Perfect 

SCORE. 


Score 

ALLOWED 


Remarks. 


Bacteria 


35 

15 
10 

15 

15 

5 
5 




Bacteria found perl 
cubic centimeterj 

Co\vy, bitter, feed,l 
flat, strong j' " 


Flavor and odor 




Sediment 




Fat. 




Per cent 


Solids not fat 




Per cent 


Temperature (street 
samples) . 


("Degrees 


or 


< or 


Acidity (prepared sam- 




Per cent 






Bottle and cap 


fBottle- _.. -.- 


Total - 


100 




[cap. 








Exhibitor ..... 


Address — 


{Signed) 






Jiidges. 

Date - -— 



786 



ScoRii Cards 



DIRECTIONS FOR SCORINc. 



BACTERIA PER CUBIC CENTIMETER— PERFECT SCORE, 35. 



PorNTS. 

i 500 and under... 35 

501-1,000- 34.9 

1,001- 1,500 34.8 

1,501- 2,000 34.7 

2,001- 2,500 34.6 

2,501- 3,600 34.5 

3,001- 3,500 34.4 

3,501- 4,000 34.3 

4,001- 4,500 34.2 

4,501- 6,000 34.0 

5,001- 6,000 33.8 

6,001- 7,000 33.6 

7,001- 8,000 33.4 

8,001- 9,000 33.2 

9,001-10,000 33.0 

10,001-11,000 32.8 

11,001-12,000 32.6 

12,001-13,000 32.4 

13,001-14,000 32.2 

14,001-15,000 32.0 

15,001-20,000 31.0 

20,001-25,000 30 



Points. 

25,001- 30,000 29 

50,001- 35,000 28 

35,001- 40,000 - 27 

40,001- 45,000 26 

45,001- 50,000 25 

50,00r- 55,000 24 

55,001- 60,000 23 

60,001- 65,000 22 

65,001- 70,000— 21 

70,001- 75,000 20 

75,001- 80,000 - 19 

80,001- 85,000 18 

85,001- 90,000 17 

90,001- 95,000 16 

95,001-100,000 15 

100,001-120,000 12.5 

120,001-140,000 10.0 

140,001-160,000 7.5 

160,001-180,000 _... 5.0 

180,001-200,000 2.6 

Above 200,000 



beO. 



Note. — When the number of bacteria per cubic centimeter exceeds the local legal limit the score shall 



FLAVOR AND ODOR— PERFECT SCORE, 16. 

Deductions for disagreeable or foreign odor or flavor should be made according to conditions found. 
When possible to recognize the cause, it should be described under " Eemarks." 

SEDIMENT— PERFECT SCORE. 10. 

Jlxamlnation for sediment may be made by means of a sediment tester, and the resulting cotton disks 
compared with standards; or the sediment may be determined by examination of the bottom of the milk 
in the bottle. In the latter case the milk should stand undisturbed for at least an hovu before the examina- 
tion. Raise the bottle carefully in its natural upright position imtil higher than the head. Tip slightly 
and observe tho bottom of the milk with the naked eye or by the aid of a reading glass. The presence of 
the slightest movable speck makes a perfect score impossible. Further deductions should be made 
according to tho miantity of sediment found. When possible, the nature of the sediment should be 
described imder "Remarks." 



FAT IN MILK— PERFECT SCORE. 15. 



Points. 

4.0 per cent and over 15 

3. 9 per cent 14 

3. 8 per cent 13 

3. 7 per cent 12 

3. 6 per cent 11 

3. 5 per cent 10 

3.4 percent 9 



Points. 

3.3 percent 8 

3. 2 per cent 7 

3. 1 percent 5 

3.0 per cent 3 

2. 9 per cent 1 

Less than 2.9 per cent 



Note.— When the per cent of fat is less than the local legal limit the score shall be 
SOLIDS NOT FAT— PERFECT SCORE, 15. 



Points. 

8. 7 per cent and over 15 

8. 6 per cent 13 

8. 5 per cent 11 

8. 4 per cent... 9 

8.3 percent 7 



Points. 

8. 2 per cent 5 

8.1 percent 3 

8 percent 1 

Less than 8 per cent 



HoTE. — When the per cent of sohds not fat is less than the local legal limit the score shall be 0. 
TEMPERATURE (STREET SAMPLES)— PERFECT SCORE, 5. 



Points. 

SOdegrees F. and below 5 

51 to 53 degrees 4 

64 to 66 degrees 3 



Points. 

57 to 60 degrees 1 

Above 60 degrees -- 



ACIDITY (PREPARED SAMPLES)— PERFECT SCORE. 6 



Points. 

0. 2 per cent and less.. - 5 

0.21 percent . 4 

0.22 per cent. .„ _. 3 



Points. 

0.23 percent 2 

0.24 percent 1 

OverO.24 percent 



BOTTLE AND CAP— PERFECT SCORE, 5. 

Deductions in score should be made for dirty or chipped bottles; for caps which do not cover the lips 
■ of the bottles, or do not fit properly in the cap seats. ' — <^ 

{Bacteria 85 
Flavor aiid odor 25 
Patg .^.10 
Solids not fat...., 10 
Acidity"' " 
Bottle and cap 5 



Skim-Milk 



^87 



Skim-milk. The scoring of skim-milk has heretofore received 
very little consideration. The greater value now placed upon 
skim-milk as a food and the larger application of skim-milk prod- 
. ucts as a food and in the arts, makes it very desirable to have 
a score card that gives in a systematic way the respective points 
that good skim-milk should possess and provide space for record- 
ing the necessary data relating to samples scored. 

The score card need not differ in principle from that used for 
whole milk but the credits allowed for the different points may 
vary somewhat in proportion to their influence upon the value 
of the skim-milk in the use that is to be made of it. The ex- 
planation of scores given for whole milk may be applied also 
for skim-milk. 



Owner . 
Address 
Class ... 



SCORE CARD FOR SKIM-MILK. 



Date 

Exhibit No. 



Item 


Score 


Remarks : 




Perfect 


Allowed 




Bacteria 


35 






Flavor and odor 


20 






Sediment 


10 






Solids not fat 


15 






Temperature (street 
sample . 


5 












Acidity 


5 






Fat 


5 












Container 


5 






Total 


100 







Date scored. 



Judges 



I 



Score Cards 
UNITED STATES DEPARTMENT OF AGRICULTURE, 



BUREAU OF ANIMAL INDUSTRY, 

DAIRY DIVISION. 



SCORE CARD FOR CREAM. 



Place 
Class 



Exhibit JVb. 



ITEM. 



Bacteria 



Flavor and odor 
Sediment 



Fat. 



Temperature (street 

samples) -- 

or 

Acidity (prepared sam- 
ples). — 



Bottle and cap 
Total ... 



Perfect 

SCORE. 



35 

25 
10 

20 



100 



Exhibitor. 
Address .... 
{Signed) 



Score 

ALLOWED. 



Beuabks. 



Bacteria found per"! 
cubic centimeter/ ■ 

Cowy, bitter, feed,"! 
flat, strong j' 



Per cent. 



or 
Per cent. 



[Bottle. 
[Cap .... 



Date. 



Judges. 



Cream 
directions for scoring. 



789 



BACTERIA PER CUBIC CENTIMETER— PERFECT SCORE. 35. 



500 and under - I 

501-, 1,000 \ 

1,001- 1,500 . I 

1,501- 2,000 i 

2,001- 2,500 i 

2,501- 3,000 ; 

3,001- 3,500- - i 

3,501- 4,000 i 

4,001- 4,500 c 

4,501- 5,000 c 

5,001- 6,000 ; 

6,001- 7,000 ; 

7,001- 8,000 ; 

8,001- 9,000 ! 

9,001-10,000 : 

10,001-11,000 : 

11,001-12,000 ; 

12,001-13,000 ! 

13,001-14,000 ! 

14,001-15,000 ; 

15,001-20.000 ! 

20,001-25,000 ! 

Note. — When the number of bacteria per 
shall be 0. 



Points. 

25,001- 30,000 29 

30,001- 35,000 28 

35,001- 40,000 ,. 27 

40,001- 45,00a. - 26 

45,001- 60,000 25 

50,001- 55,000..., 24 

55,001- 60,000 23 

60,001- 65,000.... 22 

65,001- 70,000 21 

70,001- 75,000 20 

75,001-80,000. 19 

80,001- 85,000 18 

85,001- 90,000. w 17 

90,001- 95,000 16 

95,001-100,000... 15 

100,001-120,000 12.5 

120,001-140,000 10.0 

140,001-160,000 7.5 

160,001-180,000. 6.0 

180,001-200,000. 2.6 

Above 200,000 

centimeter exceeds the local legal limit the score 



FLAVOR AND ODOR— PERFECT SCORE. 25. 

Deductions for disagreeable or foreign odor or flavor should be made according to conditions tound. 
When possible to recognize the cause of the difficulty it should be described under " Remarks." 

SEDIMENT— PERFECT SCORE, 10. 

Examination for sediment should be made only after the cream has stood for at least an hour undis- 
turbed in any way. Raise the bottle carefully in its natural upright position until higher than the 
head. Tip slightly and observe the bottom of thf cream with the naked eye or by the aid of a reading 
glass. The presence of the slightest movable speck makes a perfect score impossible. Further deduc- 
tions should be made according to the quantity o{ sediment found. When possible the nature of the 
sediment should be described under "Remarks." 



FAT IN CREAM— PERFECT SCORE. 20. 



Points. 

25 per cent and above 20 

24 percent 19.5 

23 per cent 19 

22 per cent 18.5 

21 percent 18 

20 per cent . 17.5 



Points. 

19 per cent 17 

18 percent 18 

17 percent 12 

16 percent 8 

15 percent 4 

Less than 15 per cent 



Note.— ^Vhen the per cent of fat is less than the local legal limit the score shall be 0. 



TEMPERATURE (STREET SAMPLES)— PERFECT SCORE. 5. 



Points. 

50 degrees F. and below 5 

51 to 53 degrees 4 

54 to 56 degrees .- 3 



Points. 

57 to 60 degrees. , 1 

Above 60 degrees * 



ACIDITY (PREPARED SAMPLES)— PERFECT SCORE. 6. 



Points 

0. 2 per cent and less 6 

0.21 percent — 4 

0.22 per cent.. 3 



POINTS. 

0.23 percent.. 2 

0.24 percent 1 

Over 0.24 per cent 



BOTTLE AND CAP— P6RFECT SCORE, 6. 

Deductions in score should be made for dirty or chlnped bottles; for caps which do not oover theUps 
,of the twttles, or do not fit properly In the cap seats. 



790 Score Cards 

Cream: The method of scoring cream is essentially the same 
as that applied in scoring milk. It is not ordinarily scored for 
solids not fat. Whether it should receive such a score or not, 
is a debatable question. Where the minimum percentage of fat 
in cream is fixed by legislative or similar enactments, full credit 
may be allowed if the composition conforms to such fat standard. 
It is customary, however, to require the presence of at least 20 
per cent of fat in cream in order to be entitled to the full score. 

SCORE CARD FOR BUTTER. 

The systematic scoring of butter is carried out in commercial 
transactions between producers and dealers and between the deal- 
ers themselves. It is also practical in scoring butter at butter 
exhibitions and in giving instruction in dairy schools. The prac- 
tice does not extend to an}^ great extent to the commercial trans- 
actions taking place between the ultimate retailer and consumer. 
As the practice of scoring butter has continued over a long 
period of years, the system has become fairly well fixed, and the 
factors that affect quality satisfactorily established. 

Butter score cards may vary somewhat in form according to 
the use that is to be made of the score. In general they include 
the factors and take the general form of the card shown here as 
an example. 

Flavor: This is the most important factor in fixing the score, 
and perfect flavor is rarely if ever given. 

Body: The ideal butter is firm, hard and waxy which prop- 
erties prevent it from softening or melting too easily. Poor body 
is described as weak, greasy, leaky, short-grained and sticky. 
The "body" of butter is not of such importance to the consumer 
as that of flavor, and recent methods of manufacture have not 
contributed toward improving it. 

Color : The shade of yellow color in butter varies in different 
markets. All require that it be uniform, that is, free from 
streaks, mottles, waves and specks. Where there is too much 
color it is said to be too high and where the yellow is too pale 
the color is said to be too light. 

Salt: The percentage of salt also varies according to the 
demands of the trade, which in turn, is governed by the likes and 
dislikes of the consumer. If the salt is not all in solution or is 
not evenly distributed the score is reduced. 



Butter 



791 



Package: The package is controlled by market requirements. 
In any case it must be substantial, attractive, neat and clean. 
The interior wrapper should be free from wrinkles, properly fold- 
ed and the workmanship good throughout. 



(3wner . 
Address 
Class ... 



SCORE CARD FOR BUTTER. 
Date 



E.xhibit No. 



Quality 
factors 


Perfect 
score 


Score 
Allowed 


Remarks : 


Flavor 


45 






Body 


25 






Color 


15 






Salt 


10 






Package 


5 






Total 


100 







Fat 

Moisture 
Salt . . . 
Casein . 



. per cent 
. per cent 
.per cent 
. per cent 



Date scored. 

f 

Judges \ 

[ 



Butter is graded on the market according to the score it re- 
ceives. 

The grade given by the New York Mercantile Exchange cor- 
responds with the score as follows : 

Grade : Higher scoring Extras Firsts Seconds Thirds 

Score: 93 or above 92 91 to 88 87 to 83 82 to 76 

Other classifications sometimes are "Packing stock", "ren- 
ovated", and to butter of inferior quality "cooking butter", 
"ladels" and "grease". 

While different judges may check closely on the score, butter 
that satisfies the best trade in one market may not do so in 
another, thus the same butter might receive a different score and 
grade on two different markets, like, for example, Boston and 
New York. Also, when the supply is short and demand strong, 
butter that would ordinarily go into one grade may be raised 
a grade higher, and when the opposite conditions prevail it might 
be dropped a grade lower. This practice is confusing until trade 
customs are learned. 



792 



Score; Cards 



Flavor: It consists of those properties that affect the senses 
of taste and smell. Nearly ever}^ one can become proficient in 
judging butter by intelligently using the senses of sight, taste 
and smell, although such physical tests are very difficult to 
describe. A number of terms are used in describing flavor as 
it varies widely and is due to many causes. Those tastes or odors 
which are pleasing and which develop in one an appetite or desire 
to eat more of the butter receive credit while those that have the 
opposite effect reduce the score. Such terms as clean, creamy, 
pleasant, delicate, and sweet are favorable, while the following 
are unfavorable : cowey, barney, old, strong, tallowy, rancid, 
fishy, fruity, and weedy. 

CULTURE SCORE CARD. 

Culture or starter, as the term applies in dairying, is an 
active culture of bacteria that are used for the purpose of 
developing lactic acid fermentation in milk and milk derivatives. 
It finds its greatest application in the manufacture of butter, 
cheese and milk beverages. Quality in starter is of first impor- 
tance as it transmits its properties to the material to which it is 
added and when the quality is poor it may be the cause of con- 
siderable loss. 

The factors that contribute to quality in a good culture are 
not unlike those for buttermilk. The score cards proposed usual- 
ly follow the same general outline. The one used by the Dairy 
Department of the N. Y. State College of Agriculture at Cornell 
University will serve as an example : 

CORNELL CULTURE SCORE CARD. 





Score 






Perfect 


Allowed 




Flavor 


50 
20 

20 
10 






Aroma 




Clean, agreeable acid. No 

undesirable aroma. 
0.6 per cent — 0.8 per cent. 
Before breaking up: Jelly 


Acidity 




Body 






Total 


100 




like, close, absence of gas 
holes. No free whey. After 
breaking up: smooth, 
creamy, free from gran- 
ules or flakes. 



I 



Buttermilk 



793 



THE BUTTERMILK SCORE CARD. 

The value of good buttermilk as a food and healthful stimu- 
lating beverage is generally acknowledged but in the past methods 
for regularly producing the desired flavors and aroma were lack- 
ing. Recent improvement in methods of handling milk combined 
with a better understanding of the principles that control fer- 
mentation is rapidly overcoming these difficulties and it is now 
possible by the use of proper methods and improved equipment 
to regularly produce buttermilk of high quality having the same 
desirable properties from day to day. 

There is need for a better general knowledge of the factors 
that produce quality in buttermilk since quality must be depend- 
ed upon to increase the demand. The use of a score card will 
be a help in gaining this desirable end in the same way that it 
has been of so much service in improving the quality of market 
milk. The following score card may be adapted to the purpose : 

BUTTERMILK SCORE CARD. 



Owner .. 
Address 
Class .... 



Date 

Exhibit No. 



Quality 


Score 


Remarks : 


factor 


Perfect 


Allowed 


Flavor 


45 




Clean, delicate, pleasant, de- 


Aroma 


15 




sirable acid. 
Clean, agreeable, attractive, 


Body 


15 




delicate, mild. 
Smooth, even, jelly-like, 

close, creamy. 
0.7 per cent to 0.9 per cent. 

Clean, neat, substantial, non- 
corrosive. Oderless. 


Acid 


15 




Container 


10 




Total 


100 





Date scored. 



Judges 



794 Score Cards 

CHEESE SCORE CARDS. 

The quality of cheese is affected by (1) the quality of the 
milk that enters into it, (2) the method applied in its manufacture 
and (3) by the fermentation that takes place during the making 
process, curing and storage. The defects may be many and 
varied and it requires practice, study and experience to become 
skilled in detecting them, and especially to assign proper credits 
to the points of merit which will correctly indicate commercial 
value. The properties that have been adopted as a basis for 
scoring cheddar cheese are (1) flavor, (2) body and texture, (3) 
color and (4) finish. 

The flavor of high qualitj^ cheese is very characteristic yet so 
unlike other substances that it is difficult to describe. It is slight- 
ly salty, mingling the flavor of fat with acid and protein sub- 
stances in a way that yield a very attractive rich flavor some- 
times described as mildly nutty. Unpleasant and offensive odors 
and tastes should be absent. 

Flavors: Volatile substances from the feed of the cows pro- 
ducing milk are sometimes transmitted to the cheese. They are 
known as weedy or feedy flavors. They vary according to the 
flavor of feed. "Cowey" flavor remind one of the odor of the 
breath of a cow. Sweet flavors characteristic of some of the 
common fruits are described as fruity. They may be derived 
from fermentations caused by organisms found in decomposing 
milk substance and indicate that the milk from which the cheese 
was made came in contact with unsanitary conditions. Cheese that 
has a pronounced sour smell or taste is described as acid. It is due 
to the presence of an excess of acid. Flat flavor indicates an 
absence or reduction in the flavors present in high quality cheese. 
Other terms are bitter, rancid, tallowy and mouldy. 

Texture and Body: When the texture of the cheese is good 
there should be no holes and the broken ends of a plug should 
appear close, solid, compact and well annealed, yet flakey and 
somewhat like broken flint. When pressed and rubbed between 
the thumb and finger it should feel smooth, silky and waxy. 
Body refers to the firmness or consistency of the substance. It 
is judged at the same time and in the same manner as the texture. 

When the body is good it will feel somewhat firm under pres- 
sure, but not too firm, and when pressure is applied it should not 



Chuese 



795 



break or crumble but yield in form like cold butter. It should 
not feel harsh or gritty nor soft and pasty. Stiff, corky, curdy, 
weak-bodied, salvy, and watery are self explanatory terms used 
in describing cheese body. 

. Color: Color is ordinarily considered perfect if it is uniform. 
The depth of the shade of yellow is not important as long as it 
satisfies the demands of the market in which it is sold. The 
fancy or whim of different markets vary in respect to the shade 
of 3^ellow color. 

Finish: Finish is important as it is likely to be taken as an 
index of the workmanship put into the manufacturing process 
which in turn has so much to do with quality in cheese. Finish 
may or may not include the package or box — but a dirty, dilapi- 
dated and untidy container should never be used. The surface of 
the cheese should be clean, smooth and free from cracks. The 
edges should be even and the bandages neaitly arranged, giving 
an impression of value and quality. 



Owner . 
Address 



SCORE CARD FOR CHEDDAR CHEESE. 



Date 

Exhibit No., 



Item 


Score 


Remarks 


Perfect 


Allowed 


Flavor 


45 






Body and 

texture 


30 






Color 


15 






Finish 


10 






, Total 


100 







Date scored. 



Judges 



SCORE CARD FOR COTTAGE CHEESE. 

Cottage cheese is one of our most wholesome food products. 
With the large surplus of milk solids not fat always available its 
use should greatly increase. Good quality will do much to 
stimulate consumption. The authors are suggesting the follow- 
ing score card in grading this product. 



796 



Owner . 
Address 



Score Cards 
score card for cottage cheese. 

Date 



Item 


Score 66 


Remarks: 


Perfect 




Flavor 


50 




Mild, clean, acid flavor. 


Viscosity and 
texture 


20 




Body or viscosity fairly 
firm. Smooth to the taste. 


Color 


5 




Creamy cast. A little odor 
enhances its commercial 
value. 




Appear ance of 
package 


5 


.--._ 


Neat, clean with every evi- 
dence of careful work- 
manship. 


Composition .... 


20 




Sufficient total solids to 
give good food value to 
the product. 


Total 


100 







Date scored. 



Judges 



SWISS CHEESE. 

In scoring Swiss Cheese special attention is given to its typical 
nutty flavor and slightly sweet, pleasing taste. Off flavors, de- 
rived from the milk or undesirable fermentation, should be 
wholly absent. The characteristic ''eyes" or holes should be 
rather evenly distributed from one to three inches apart. They 
are normall.y from one-half to three fourths of an inch in diam- 
eter. The substance between the eyes should be compact, and 
free from small holes which indicate that undesirable gas pro- 
ducing fermentation has occurred. 

The salt should have passed well through the cheese. The 
body should be firm and the rind smooth, clean and free from 
cracks. 



Owner . 
Address 
Class ... 



Cheese 
score card for swiss cheese. 

Date 

Exhibit No 



797 



Item 




Score 


Remarks : 


Perfect 


Allowed 


Flavor 


40 










Holes and appearance . . . 


25 






Texture 


20 










Salt 


10 












Style 


5 






Total 


100 







Date scored. 



Judges -I 



LIMBURGER CHEESE SCORE CARD. 

Limburger cheese is subject to most of the defects that are 
common to other kinds. Its peculiar flavor is not easy to obtain 
without defect, as in the process of manufacture it is difficult to 
control some of the common undesirable forms of bacteria when 
they once gain entrance to the milk from which the cheese is 
made. Gassy cheese is a common defect due to the presence of 
gas forming bacteria. The body of the cheese is filled with gas 
holes and bloats until the sides are more or less bulged and 
rounded. Too much acid development results in sour cheese that 
cures slowly and develops a bitter taste. Other defects are dry- 
ness which causes the cheese substance to be hard and to cure 
slowly, while too much moisture results in a pasty, rapidly cur- 
ing cheese that will not hold its shape well. The cheese should 
keep its regular shape, the substance should be uniform through- 
out and the rind free from cracks. 



798 



ScoRK Cards 



Owner . 
Address 
Class ... 



SCORE CARD FOR LIMBURGER CHEESE, 

Date received 

Exhibit No 



Item 


Score 




Perfect 


Allowed 




Flavor 


40 






Texture 


40 






Color 


10 






Salt 


5 












Style 


5 






Total . ; 


100 







Date scored. 



r 

Judges -j 



SCORE CARD FOR ICE CREAM. 

The scoring of ice cream does not differ materially from the 
scoring of other dairy products excepting that in judging quality 
in added flavor the ideal for the flavor used should be the stand- 
ard of comparison. The principal factors that have an influence 
on quality in ice cream are usually described under the follow- 
ing headings : Flavor, body, texture, appearance, and package. 

Flavor: Flavor may be described under two headings, (1) 
that derived from added flavoring, (2) that derived from other 
materials. If the added flavoring is not of high quality it may 
introduce "foreign" flavors and leave the cream "low" in the 
desired flavor. If too much flavoring is added it may be so 
pronounced as to taste too "sharp" or slightly "bitter", leaving 
a sensation that is slightly unpleasant. There should be just 
sufficient flavoring present to enable the consumer to identify it 
but not enough to smother or detract from the pleasant taste of 
other high grade materials present. "Rancid", "mouldy" and 
"stale" flavors may be derived from carelessly sorted nut meats 
and fruits. Sweetness should not be too pronounced, nor lack- 
ing to such an extent as to produce a "flat" taste. 

The flavors imparted to ice cream by milk products are nu- 
merous and variable in strength. The highest quality yields to 



let Cream 799 

the tongue and palate the delicate aroma and sensation of rich- 
ness that is so pleasing in sweet, fresh, clean cream. Some be- 
lieve that a slightly acid development, hardly enough to be recog- 
nized, tends to liven the flavor and improve it. All of the flavors 
that appear in milk or cream of poor quality may be carried into 
the frozen product. The common ones are sour, old, cowey, bit- 
ter, metallic, oily, muddy, barn, unclean, burned and overheated 
flavors. 

Other defects in flavor may be due to other ingredients added. 
Milk powder, condensed milk, gelatin and starch when added, 
each impart at times, partieularily if these products are not of 
first quality, defects in flavor characteristic of the products them- 
selves. 

Body or Viscosity. — Ice Cream should be firm and yet not 
sticky. 

Texture. Smooth and velvety to the taste. No large water 
crystals. No milk sugar crystals causing "sandiness". 

Defects in texture are described as icy, coarse, sticky, buttery 
or soft. Allowance must always be made for fruits or nuts added 
in manufacturing. 

Composition. — The ice cream should not fall under the legal 
or trade standards. Both the fat and total solids should be taken 
into consideration. Increased importance is being attached to 
composition when scoring ice cream. 

Bacteria. The bacterial content is frequently overlooked, and 
more importance should be attached to it. Baer^ states : 
"The bacterial content of a perfect ice cream should be not 
more than 20,000 to the cc. One point should be deducted for 
every increase of 10,000 bacteria to the cc, until 100,000 is reached, 
when two points should be deducted for every increase of 50,000 
to the cc". 

Appearance. The color should be characteristic of the fruit 
or flavor used. The general appearance should be clean. 

Package. Container to be clean, free from rust and from all 
evidences of slovenly workmanship. Brick ice cream should be 
neatly packaged. 

Several ice cream cards have been proposed, but none have 
been generally accepted. The four best known are as follows : 



800 



ScoRr; Cards 



(1.) Vermont Score 
Card/ 

Flavor 45 

Texture 20 

Richness 20 

Appearance 10 

Color 5 

100 



(2.) Iowa Score Card/ 

Flavor 45 

Body 20 

Texture 20 

Permanency 10 

Package 5 

100 



(3.) Wisconsin Score 
Card." 

Flavor 40 

Bacteria 20 

Texture and body. 20 

Fat 10 

Appearance & color 5 
Package 5 

100 



California Score Card." Approved by Dairy Division, Uni- 
versity of California, Davis, Calif. 



Items 


Possible Score 


Amount 
Allowed 


Flavor and palatability .... 


50 




Texture and bodv 


25 








Appearance (color) 


10 




"A" butterfat 


5 




"B" total solids 


10 




Total 


100 





Analysis : 



Per cent 



Remarks : 



Butterfat 



Total solids 



"A"- — A perfect score shall be allowed ice cream containing 

10-12 per cent butterfat, inclusive. 
Deduct 1 point for each Vs per cent above 12 per cent. Less 

than 10 per cent score' is 0. 
"B" — A perfect score shall be allowed ice cream containing 

36 per cent total solids or above. 
For each per cent less than 36 per cent, deduct 2 points. 



Judges 



I 



While the manuscript for this cliapter was being set up there 
appeared the "Report of the Committee on Legal Standards and 
Score Cards for Dairy Products" of the American Dairy Science 
Association.- The following is taken from the above report: 



Condensed Milk 



801 



(5). Score card for ice cream tentatively recommended by 
the above committee : 

Flavor 40 

Body and texture 25 

Fat and solids 10 

Bacteria 20 

Package 5 



100 



SCORE CARD FOR PLAIN SUPERHEATED CONDENSED WHOLE 

OR SKIM-MILK. 

The authors are suggesting the following score card for plain 
superheated condensed whole or skim-milk. Explanation ac- 
companies each item to be scored. Products of this class are 
practically always marketed in bulk. 

Suggested Score Card for plain superheated whole or skim-milk. 



Item 


Score 


Allowed 


Remarks 


Viscosity 


15 




Heavy viscosity. Product 
to flow freely from 
container. 


Homogeneity 


15 




Smooth, velvety appear- 
ance. No visible specks 
or lumps. 


Ctolor 


10 




Light, white, milky color. 


Flavor 


30 




Good, clean milk flavor. 




No foreign flavors. 


Odor 


5 




No appreciable odors of 




any kind. 


Appearance c o n - 
tainer . . . 


5 




Container to be neat, 
clean and with all evi- 




dences of good work- 
manship. 


Fat 


10 




No foreign fats. Fat 




content to conform to 
legal or trade require- 
ments. 


Total solids 


10 




No preservatives of any 
kind. Total solids to 
conform to legal or 
trade requirements. 


Total 


100 







802 vScoRR Cards 

SCORE CARD FOR EVAPORATED MILK. 

No score cards for evaporated milk are known to have been 
published. The authors are suggesting the following score card, 
which takes into consideration the physical properties, appearance 
of the container, composition and net weight. Explanation is 
made of each item to be scored. 

Among the more common defects encountered when scoring 
evaporated milk to determine its commercial value, the follow- 
ing can be mentioned : 

(1). Viscosity either too light or too heavy, due to improper 
processing, or to incorrect handling after sterilizing. 

(2). Fat separated due to improper homogenization. 

(3). Color either too light due to insufficient sterilization, 
or too dark due to excessive sterilization or to the age of the 
product. 

(4), Off flavor caused by foreign substances, or by decom- 
position due to bacterial development when the product is not 
properly sterilized. The use of raw milk products of poor quality 
may cause off flavors. 

(5). Off odors caused usually by bacterial development as a 
result of improper sterilization. 

(6), Sediment upon bottom of cans, caused by the crystal- 
lization of the lime salt of citric acid. This appears only in prod- 
ucts of considerable age. Particles of foreign matter and lumps 
of coagulated casein, are sometimes found. 

(7). Evaporated milk is usually served at the table out of 
the original container. For this reason defects in the package 
should be carefully noted. Soiled and poorly applied labels and 
dirty or rusty cans all deduct from the score. 

(8). The composition and net weight of the cans are of 
great commercial importance. If under the advertised claims, it 
detracts from the commercial value of the product, and the score 
should be very liberally cut. No foreign fats or preservatives of 
any kind should be present. 



Evaporated Milk 



803 



SUGGESTED SCORE CARD FOR EVAPORATED MILK. 

Owner Date 

Address Brand 

Plant where manufactured 



Size. 



Item 


Score 


Remarks : 


Perfect 


Allowed 


Viscosity 


15 




Good viscosity, but not enough to 
flake in water or coffee. Suf- 
ficient to convey correct impres- 
sion of its value. 


Homogeneity . . 


15 




No fat separated. No specks or 
lumps. Product smooth and 
homogeneous throughout. 


Color 


5 




Medium color like heavy cream. 




Neither too white nor too dark. 
Sufficient color to insure safe 
sterilization. 


Flavor 


30 




Rich, nutty flavor. Cooked taste 
not too pronounced. No foreign 
flavors. 


Odor 


2 




No appreciable odors of any kind. 


Sediment 


3 




No lumps of coagulated casein. 
No foreign matter. No precipi- 
tate of calcium citrate. 


Appearance con- 
tainer 


5 




Neat labels properly applied. Ends 
of cans well polished, and not 
bulged. 


Fat 


10 




No foreign fats. No preservatives. 
Fat content to conform to legal 
requirements. 




Total solids .. 


10 




Total solids content to be not un- 
der legal requirements. 


Net weight . . . 


5 




Net weight to be not under 
amount specified upon the label. 


Total 


100 







The following score card for evaporated milk is taken from 
the "Report of the Committee on Legal Standards and Score 
Cards," cited above -^ 

Tentative Score Card for Evaporated Milk recommended by- 
above committee : 



804 Score Cards 

Flavor and odor 40 

Body and texture 35 

Color 5 

Fat content 10 

Total solids 10 
Adulterants and preservatives must be absent 



100 

The following comments are made by the committee upon the 
various points in the above score : 

Flavor and odor. Perfect : Must be fresh, sweet and free 
from off flavors. Deduct 1 to 10 points if metallic, rancid and 
stale. Deduct 40 points if sour, bitter, putrid, gassy or other- 
wise fermented. 

Body and texture. Perfect: Must be creamy, of uniform 
emulsion, smooth. Deduct 1 to 10 points each for curdy milk, 
separated or churned milk. 

Color. Perfect: Must be creamy. Deduct 1 to 3 points if 
brown. 

Fat content. Perfect: Must contain not less than 9 per 
cent milk fat. Deduct one point for each one-half per cent less 
than 9 per cent. Deduct 10 points if less than 7.8 per cent, the 
present Federal Standard. 

Total solids. Perfect: Must contain not less than 28 per 
cent solids. Deduct 1 point for each 1 per cent or fraction 
thereof, less than 28 per cent. Deduct 10 points if below 25,5 
per cent, present federal standard. 

Adulterants and preservatives. Perfect : Must be free from 
all adulterants or preservatives. If it contains animal or vege- 
table fats, or other ingredients foreign to the composition of 
normal milk, or any preservatives deduct 100 per cent. 

SCORE CARD FOR SWEETENED CONDENSED MILK 

The authors are suggesting the following score card for sweet- 
ened condensed skim-milk. It takes into consideration the phys- 



SwiCiiTiiNKD Condensed MitK 805 

ical properties, appearance of the container, composition and net 
weight. The same score card can be applied with slight modifi- 
cation to both the whole and skim-milk. The various physical 
properties are the same in either case. In the case of the sweet- 
ened condensed skim-milk, the score allowed under fat can be 
included with the total solids, since composition is of equal im- 
portance in either case, and upon it depends to a large extent 
the commercial value of the product. Brief explanation follows 
each item in the score. 

Large quantities of sweetened condensed milk are sold in bulk, 
being marketed either in barrels or in milk cans. Bulk sweet- 
ened condensed milk can be judged by using the same scale of 
points as in the case of the canned milk. The appearance of the 
container is of importance whether the product is marketed in 
bulk or in cans. 

The more common defects encountered in scoring sweetened 
condensed milk, are the following : 

(1). Viscosity either too light, or too heavy. 

(2). Fat separated upon the top of the milk or milk sugar 
separated upon the bottom of the container. These defects oc- 
cur in varying degrees. Lumps and specks rendering product 
not homogeneous. 

(3). Product slightly or badly discolored, caused by im- 
proper manufacturing processes. 

(4). Off flavors caused by mould development. Too much 
cooked or burned taste. Yeasty flavors. 

(5). Bad odors described as manurial, tallow, rancid or 
yeasty. 

(6). Container lacks neatness. Too much air space on top 
of the milk in the container. 

(7). Composition and net weight under standard claimed, 
whicli detracts considerablv from the score. 



806 



Score Cards 



SUGGESTED SCORE CARD FOR SWEETENED CONDENSED MILK 

Owner Date 

Address Brand Size 

Plant 



Item 


Score 


Allowed 


Eemarks : 


Viscosity 


10 




Neither too light nor too heavy in 
viscosity. Sufficiently fluid to pour 
from container. 


Homogeneity . . . 


10 




No fat separated. No milk sugar set- 
tled upon bottom of container. 
Product smooth to taste and free 
from foreign matter. 


Color 


! 6 




Slight yellowish cast. Neither too 
light nor too dark. 


Flavor 


25 




Clean milk flavor without any foreign 
flavor other than the sugar added. 


Odor 


2 




No appreciable odors of any kind. 
No signs of yeast development. 




Solubility 


5 




Product to dissolve freely in water, 
without showing any undissolved 
matter. 


Appearance o f 
container . . . 


3 




Neat label, properly applied.. No rust 
spots upon tin surfaces. If bulk 
container, should be neat and at- 
tractive. 


Bacteria 


10 




Bacteria to be present in amounts not 
to exceed the limits found in prop- 
erly pasteurized milk. No yeast 
cells to be present. 


Fat 


10 




Fat to be not under legal or trade 
standards. Score for fat to be add 
ed to total solids in the case of the 
skimmed product. No foreign fats 
allowed. 


Sugar 


5 




For sweetened condensed skim-milk, 
sugar to be about 42.00 per cent, 
and for whole milk about 44.50 per 
cent. 


Total solids . 


10 




Milk solids to conform to legal stand- 
ards. Total solids to conform to 
trade standards. No adulterants. 


Net weight . . . 


5 




To be not under amount specified 
upon the label. 


Total 


100 







The following score card for sweetened condensed milk is 
taken from - cited above. 



SwKKTKNKI) CONDF.NSKD MiLK 807 

Tentative score card for sweetened condensed milk, recom- 
mended by the above coniinittee : 

SCORE CARD FOR SWEETF:NED CONDENSED MILK. 

Perfect score, 
Properties. per cent. 

Flavor and odor 30 

Body and texture 25 

Color 5 

Fat content 10 

Milk solids 10 

Bacteria 10 

Sugar 10 

Adulterants and preservatives (must be absent) 

Total score 100 

SUGGESTIONS FOR USE OF SCORE CARD. 

Flavor and odor. Perfect ; must be fresh, sweet and free 
from all flavors. Deduct one to ten points each if metallic, rancid, 
stale, cheesy. Deduct one to thirty points if sour, yeasty or other- 
wise fermented. 

Body and Texture. — Perfect: Must be viscous, smooth and 
free from lumps of curd, sugar sediment and foreign impurities. 
Deduct one to five points if rough and sandy, from one to five 
points if sugar sediment in bottom, from one to five points if fat 
separation, one to five points if white and yellow buttons, 15 to 
25 points if lumps of curd. 

Color. — Perfect : Rich cream to yellow. Deduct one to five 
points if brown. 

Fat Content. — Perfect : Must contain not less than 10 per 
cent milk fat. Deduct one point for each half per cent less than 
10 per cent. If below 8 per cent, deduct ten points. Deduct ten 
points if below 8 per cent, present Federal Standard. 

Total Milk Solids. — Perfect: Must contain not less than 32 
per cent. Deduct one point for each per cent or fraction thereof 
below 32 per cent. If below 28 per cent, deduct ten points. 



808 Score Cards 

Sugar. — Perfect: The concentration shall be from 60 to 62 
per cent. Deduct two points for each per cent concentration 
below 60 or above 62 per cent. The concentration shall be deter- 
mined by dividing per cent of sugar by the sum of per cent of 
sugar and water. 

Bacteria. — Make reduction for excessive number of bacteria. 
Importance of bacterial counts have not as yet been sufficiently 
considered by the committee to Avarrant definite recommendations 

SCORE CARDS FOR WHOLE MILK, SKIM-MILK AND CREAM 

POWDERS. 

The authors are suggesting the following score card for vari- 
ous powdered milk products. Explanations follow the various 
items that go to make up the score. 

Flavor. — This largely determines the commercial value of all 
milk powders. The first signs of decomposition usually manifest 
themselves in the flavor. The principal defect in flavor is caused 
by rancidity. Any considerable amount of rancidity renders 
the powder unfit for human food. No method of treatment has 
yet been found that will completely eliminate rancidity after it 
has been once developed. The flavor should be very similar to 
that of the fluid products from which the powders were made. 

Odor. — No bad odors of any kind should be noticeable. Bad 
odors usually indicate either improper manufacturing processes, 
or decomposition of the product. 

Solubility. — The importance of solubility depends upon the 
use to which the powder is to be placed. Powder made by the 
spray process is usually more soluble than that made by the 
roller process. If the powder is to be reconstituted or used for 
making ice cream, it is very important that it be completely 
soluble. If it is used for making milk chocolate and other food 
products, its solubility is relatively not important. 

Appearance. — White to slightly yellowish cast. No dark lumps 
or specks. Powder is to be homogeneous throughout. 

Composition. — Water content not to exceed the Federal Stand- 
ard of 5 per cent. The less water the better, since the presence 
of water is the most common cause of spoilage. The fat and total 
solids are to conform to the legal or trade requirements. 



Milk Powders 



809 



SCORE CARDS FOR WHOLE MILK, SKIM-MILK AND CREAM POWDERS. 



Item 


Score 


Allowed 


Remarks : 


Flavor 


50 




Fresli, clean flavor resembling that of 
the fluid products. No signs of 
rancidity. 


Odor 


5 




Clean, agreeable odor. Suggestion of 




good milk products. 


Solubility .... 


10 




For certain iises, powder should be 
completely soluble. For other uses 
solubility is relatively unimport- 
ant. 


Appearance . . . 


10 

15 
10 




Pleasing appearance. Homogeneous 
and free from lumps or specks. 


Composition 




Not to exceed 5 per cent of water. 


Bacteria 




Not to exceed limits usually found 
in properly pasteurized milk. 



REFERENCES. 



1 Whitaker, G. M. The Score Card System of Dairy Inspection. Bu. Am. 
Ind. U. S. Dept. Agri. Cir. 199,122. 

- Frandsen, J. H. Chairman "Report of Committee on Legal Standards 
and Score Cards for Daii-y Products." Journal of Dairy Science, March 1922, 
p. 164. 

» Washburn, R. M. Vermont Station, Bulletin 155, 1910. 

* Mortensen, M. Iowa Station, Bulletin 123. 

= Baer, A. C. Wisconsin Station, Bulletin 262, 1916. 

" California and Southwestern States Ice Cream Manufacturers Ass'n. 
1921. 



CHAPTER XXI 

DEFINITIONS AND STANDARDS FOR DAIRY 
AND RELATED PRODUCTS 

Standards for dairy products group themselves into three sub- 
divisions : namely, federal,, state and municipal standards. Ob- 
viously these are continuously undergoing changes, and the 
marked lack of uniformity is very evident. 

STANDARDS OF THE U. S. DEPARTMENT OF AGRICULTURE. 

The following definitions and standards are taken verbatim 
from the federal regulations as promulgated by the TJ. S. Secre- 
tary of Agriculture down to the time of going to press.^ These 
definitions and standards are all a result of the labors of the 
"Joint committee on Food and Drug definitions and standards" 
of which Dr. Julius Hortvet is chairman. The definitions have 
been adopted in whole or in part by many of the state authorities. 

Milk and Milk Products 

Milk. — 1. Milk is the whole, fresh, clean lacteal secretion ob- 
tained by the complete milking of one or more healthy cows, 
properly fed and kept, excluding that obtained within fifteen days 
before and five days after calving, or such longer period as may 
be necessary to render the milk practically colostrum-free. 

2. Blended milk is milk modified in its composition so as to 
have a definite and stated percentage of one or more of its con- 
stituents. 

3. Pasteurized milk is milk that has been subjected to a temp- 
erature not lower than 145 degrees Falirenheit for not less than 
thirty minutes. Unless it is bottled hot, it is promptly cooled to 
50 degrees Fahrenheit, pr lower. 

4. Sterilized milk is milk that has been lieated at the tempera- 
ture of boiling water or higher for a length of time sufficient to 
kill all organisms present. 

[810] - 



Mii^K AND Milk Products 811 

5. Homogenized milk is milk that has been mechanically 
treated in such a manner as to alter its physical properties with 
particular reference to the condition and appearance of the fat 
globules, 

, 6. Skimmed milk is milk from which substantially all of the 
milk fat has been removed, 

7. Buttermilk is the product that remains when fat is re- 
moved from milk or cream, sweet or sour, in the process of churn- 
ing. It contains not less than eight and five-tenths per cent 
(8.5%) of milk solids not fat. 

8. Goat's milk, ewe's milk, et cetera, are the fresh, clean, 
lacteal secretions, free from colostrum, obtained by the complete 
milking of healthy animals other than cows, properly fed and 
kept, and conform in name to the species of animal from which 
they are obtained. 

9. Condensed milk, evaporated milk, concentrated milk, is the 
product resulting from the evaporation of a considerable portion 
of the water from the whole, fresh, clean lacteal secretion ob- 
tained by the complete milking of one or more healthy cows, 
properly fed and kept, excluding that obtained within fifteen days 
before and ten days after calving, and contains, all tolerances 
being allowed for, not less than twenty-five and five-tenths per 
cent (25,5%) of total solids and not less than vseven and eight- 
tenths per cent (7,8%) of milk fat. 

In the case of the standard upon evaporated milk, a tentative 
standard, wherever standardization is being practiced, of 8,00 per 
cent fat and 26.15 per cent total solids is the one that applies. 

10. Sweetened condensed milk, sweetened evaporated milk, 
sweetened concentrated milk, is the product resulting from the 
evaporation of a considerable portion of the water from the whole, 
fresh, clean, lacteal secretion obtained by the complete milking 
of one or more healthy cows, properly fed and kept, excluding 
that obtained within fifteen days before and ten days after calv- 
ing, to which sugar (sucrose) has been added. It contains, all 
tolerances being allowed for, not less than twenty-eight per cent 
(28.0%) of total milk solids, and not less than eight per cent 
(8.0%) of milk fat, 

11. Condensed skimmed milk, evaporated skimmed milk, con- 
centrated skimmed milk, is the product resulting from the evapo- 



812 Definitions and »Standards 

ration of a considerable portion of the water from skimmed 
milk, and contains, all tolerances being allowed for, not less than 
twenty per cent (20%) of milk solids. 

12. Sweetened condensed skimmed milk, sweetened evapo- 
rated skimmed milk, sweetened concentrated skimmed milk, is the 
product resulting from the evaporation of a considerable portion 
of the water from skimmed milk to which sugar (sucrose) has 
been added. It contains, all tolerances being allowed for, not less 
than twenty-eight per cent (28.0%) of milk solids. 

13. Dried milk is the product resulting from the removal of 
water from milk, and contains, all tolerances allowed for, not less 
than twenty-six per cent (26.0%) of milk fat, and not more than 
five per cent (5.0%c) of moisture. 

14. Dried skimmed milk is the product resulting from the 
removal of water from skimmed milk, and contains, all tolerances 
allowed for, not more than five per cent (5.0%) of moisture. 

15. Malted milk is the product made by combining whole milk 
with the liquid separated from a mash of ground barley malt and 
wheat flour, with or without the addition of sodium chloride, 
sodium bicarbonate, and potassium bicarbonate in such a manner 
as to secure the full enzymic action of the malt extract and by re- 
moving water. The resulting product contains not less than 
seven and one-half per cent (7.5%o) of butter fat and not more 
than three and one-half per cent (3.5% ) of moisture. 

Cream. 1. Cream, sweet cream, is that portion of milk, rich in 
milk fat, which rises to the surface of milk on standing, or is sepa- 
rated from it by centrifugal force. It is fresh and clean. It con- 
tains not less than twenty per cent (20.0%o) of milk fat and not 
more than two-tenths per cent (0.2%) of acid-reacting substances, 
calculated in terms of lactic acid, 

2. Whipping cream is cream which contains not less than 
thirty per cent (30.0%c) of milk fat. 

3. Homogenized cream is cream that has been mechanically 
treated in such a manner as to alter its physical properties, with 
particular reference to the condition and appearance of the fat 
globules. 

4. Evaporated cream, clotted cream, is cream from which a 
considerable poi'tion of water has been evaporated. 



Cheese; 813 

Cheese. 1. Cheese is the sound product made from curd ob- 
tained from the whole, partly skimmed, or skimmed milk of cows, 
or from the milk of other animals, with or without added cream, 
by coagulating the casein with rennet, lactic acid, or other suit- 
able enzj'me or acid, and with or without further treatment of the 
separated curd by heat or pressure, or by means of ripening fer- 
ments, special molds, or seasoning. 

By act of congress, approved June 6, 1896, cheese may also 
contain added coloring matter. 

In the United States, the name ' ' Cheese ' ' unqualified, is under- 
stood to mean Cheddar Cheese, American Cheese, American 
Cheddar Cheese. 

2. Whole milk cheese is cheese made from whole milk. 

3. Partly skimmed milk cheese is cheese made from partly 
skimmed milk. 

4. Skimmed milk cheese is cheese made from skimmed milk. 

Whole Milk Cheeses. 5. Cheddar cheese, American cheese, 
American Cheddar cheese, is the cheese made by the Cheddar 
process, from heated and pressed curd obtained by the action of 
rennet on whole milk. It contains not more than thirty-nine per 
cent (39%) of water, and, in the water-free substance, not less 
than fifty per cent (50%) of milk fat. 

6. Stirred curd cheese, sweet curd cheese, is the cheese made 
by a modified Cheddar process, from curd obtained by the action 
of rennet on whole milk. The special treatment of the curd, after 
the removal of the whey, yields a cheese of more open, granular 
texture than Cheddar cheese. It contains, in the water-free sub- 
stance, not less than fifty per cent (50%) of milk fat. 

7. Pineapple cheese is the cheese made by the pineapple 
Cheddar cheese process, from pressed curd obtained by the action 
of rennet on whole milk. The curd is formed into a shape re- 
sembling a pineapple, with characteristic surface corrugations, 
and during the ripening period the cheese is thoroughly coated 
and rubbed with a suitable drying oil, with or without shellac. It 
contains, in the water-free substance, not less than fifty per cent 
(50%) of milk fat. 

8. Limburger cheese is the cheese made by the Limburger 
process, from unpressed curd obtained by the action of rennet on 



814 Definitions and Standards 

whole milk. The curd is ripened in a damp atmosphere by special 
fermentation. It contains, in the water-free substance, not less 
than fifty per cent (50%) of milk fat. 

9. Brick cheese is the quick-ripened cheese made by the brick 
cheese process, from pressed curd obtained by the action of rennet 
on whole milk. It contains, in the water-free substance, not less 
than fifty per cent (50%) of milk fat. 

10. Stilton cheese is the cheese made by the Stilton process 
from unpressed curd obtained by the action of rennet on whole 
milk, with or without added cream. The cheese, ripened by a 
special blue-green mold, has a mottled or marbled appearance in 
section. 

11. Gouda cheese is the cheese made by the Gouda process, 
from heated and pressed curd obtained by the action of rennet 
on whole milk. The rind is colored with saffron. It contains, in 
the water-free substance, not less than forty-five per cent (45%) 
of milk fat. 

12. Neufchatel cheese is the cheese made by the Neufchatel 
process, from unheated curd obtained by the combined action of 
lactic fermentation and rennet on whole milk. The curd, drained 
by gravity and light pressure, is kneaded or worked into a but- 
ter-like consistence and pressed into forms for immediate con- 
sumption or for ripening. It contains, in tlie water-free substance, 
not less than fifty per cent (50*/^ ) of milk fat. 

13. Cream cheese is the unripened cheese made by the Neuf- 
chatel process from whole milk enriched with cream. It contains, 
in the water-free substance, not less than sixty-five per cent 
(65%) of milk fat. 

14. Koquefort cheese is the cheese made by the Roquefort 
process, from unheated, unpressed curd obtained by the action of 
rennet on the whole milk of sheep, with or without the addition 
of a small proportion of the milk of goats. The curd is inoculated 
with a special ripening mold (Penicillium Roqueforti) and ripens 
with the growth of the mold in the interior. The fully ripened 
cheese is friable and has a mottled or marbled appearance in 
section. 

15. Gorgonzola cheese is the cheese made by the Gorgonzola 
process, from curd obtained by the action of rennet on whole milk. 



i 



Chijksiv 815 

The cheese, ripened in a cool, moist atmosphere by the develop- 
ment of a bhie-green mold, has a mottled or marbled appearance 
in section. 

Whole Milk or Partly Skimmed Milk Cheeses. 16. Edam 
cheese is the cheese made by the Edam process, from heated and 
pressed curd obtained by the action of rennet on Avhole milk, or 
on partly skimmed milk. It is commonly made in spherical form 
and coated with a suitable oil and a harmless red coloring matter. 

17. Emmenthaler cheese, Swiss cheese, is the cheese made by 
the Emmenthaler process, from heated and pressed curd obtained 
by the action of rennet on whole milk or on partly skimmed milk, 
and is ripened by special gas-producing bacteria, causing charac- 
teristic "eyes" or holes. The cheese is also known in the United 
States as "Schweitzer." It contains, in the water-free substance, 
not less than forty-five per cent (45%) of milk fat. 

18. Camembert cheese is the cheese made by the Camembert 
process, from unheated, unpressed curd obtained by the action of 
rennet on whole milk or on slightly skimmed milk, and is ripened 
by the growth of a special mold (Penicillium Camemberti) on the 
outer surface. It contains,, in the water-free substance, not less 
than forty-five per cent (45%) of milk fat. 

19. Brie cheese is the cheese made by tlie Brie process, from 
unheated, unpressed curd obtained by the action of rennet on 
whole milk, on milk with added cream, or on slightly skimmed 
milk, and is ripened by the growth of a special mold on the outer 
surface. 

20. Parmesan cheese is the cheese made by the Parmesan 
process, from heated and hard-pressed curd obtained by the action 
of rennet on partly skimmed milk. The cheese, during the long 
ripening process, is coated with a suitable oil. 

Skimmed Milk Cheeses. 21. Cottage cheese, Schmierkase, is 
the unripened cheese made from heated (or scalded) curd ob- 
tained by the action of lactic fermentation or lactic acid or rennet, 
or any combination of these agents, on skimmed milk, with or 
without the addition of butter-milk. The drained curd is some- 
times mixed Avith cream, salted, and sometimes otherwise seasoned. 

Whey Cheeses. 22. Whey cheese (so called) is produced by 
various processes from the constituents of whey. There are a 



816 Definitions and Standards 

number of varieties each of which bears a distinctive name, ac- 
cording to the nature of the process by which it has been pro- 
duced, as, for example, "Rieotta," "Zieger, " "Primost, " "My- 
sost." 

Sugar and Sugar Products — Sugars. 1. Sugar is the product 
chemically known as sucrose (saccharose), chiefly obtained from 
sugar cane, sugar beets, sorghum, maple and palm. 

2. Granulated, loaf, cut, milled, and powdered sugars, are 
different forms of sugar, and contain at least ninety-nine and five- 
tenths per cent (99.5%) of sucrose. 

3. Maple sugar, maple concrete, is the solid product resulting 
from the evaporation of maple sap or maple syrup. 

4. Massecuite, melada, mush sugar, and concrete, are products 
made by evaporating the purified juice of a sugar-producing plant, 
or a solution of sugar, to a solid or semi-solid consistence, and in 
which the sugar chiefly exists in a crystalline state. 

Molasses and Refiners' Syrup. 1. Molasses is the product left 
after separating the sugar from massecuite, melada, mush sugar, 
or concrete, and contains not more than twenty-five per cent 
(25%) of water and not more than five per cent (5%) of ash. 

2. Refiners' syrup, treacle, is the residual liquid product ob- 
tained in the process of refining raw sugars, and contains not more 
than twenty-five per cent (25% ) of water and not more than eight 
per cent (8%) of ash. 

S3nnips. 1. Syrup is the sound product made by purifying 
and evaporating the juice of a sugar-producing plant without re- 
moving any of the sugar. 

2. Sugar-cane syrup is syrup made by the evaporation of the 
juice of the sugar-cane or by the solution of sugar-cane concrete, 
and contains not more than thirty per cent (30%) of water and 
not more than two and five-tenths per cent (2.5%) of ash. 

3. Sorghum syrup is syrup made by the evaporation of sor- 
ghum juice or by the solution of sorghum concrete, and contains 
not more than thirty per cent (30% ) of water and not more than 
tAvo and five-tenths per cent (2.5%) of ash. 

4. Maple syrup is syrup made by the evaporation of maple 
sap or by the solution of maple concrete, and contains not more 



Glucose Pkoducts 817 

than thirty-five per cent (35%) of water, and weighs not less than 
eleven (11) pounds to the gallon (231 cu. in.) 

5. Sugar syrup is the product made by dissolving sugar to the 
consistence of a syrup, and contains not more than thirty-five 
per cent (35%) of water. 

Glucose Products. 1. Starch sugar is the solid product made 
by hydrolyzing starch or a starch-containing substance until the 
greater part of the starch is converted into dextrose. Starch 
sugar appears in commerce in two forms, anhydrous starch sugar 
and hydrous starch sugar. The former, crystallized without water 
of crystallization, contains not less than ninety-five per cent 
(95%) of dextrose and not more than eight-tenths per cent 
(0.8%) of ash. The latter, crystallized with water of crystalliza- 
tion, is of two varieties: 70 sugar, also known as brewers' sugar, 
contains not less than seventy per cent (70%) of dextrose and 
not more than eight-tenths per cent (0.8%) of ash; 80 sugar, 
climax or acme sugar, contains not less than eighty per cent 
(80%) of dextrose and not more than one and one-half per cent 
(1.5%) of ash. 

Honey. 1. Honey is the nectar and saccharine exudations of 
plants gathered, modified and stored in the comb of honey bees 
(Aphis mellifica and A. dorsata) ; is laevo-rotatory, contains not 
more than twenty-five per cent (25%) of water, not more than 
twenty-five hundredths per cent (.25%) of ash, and not more than 
eight per cent (8%) of sucrose. 

2. Comb honey is honey contained in the cells of comb, 

3. Extracted honey is honey which has been separated from 
the uncrushed comb by centrifugal force or gravity. 

4. Strained honey is honey removed from the crushed comb 
by straining or other means. 

Cacao Products. 1. Cacao beans, cocoa beans, are the seeds 
of the cacao tree, Theobroma cacao L. 

2. Cacao nibs, cocoa nibs, cracked cocoa, is the roasted, broken 
cacao bean freed as far as is practicable from cacao shell or husk. 

3. Chocolate, plain chocolate, bitter chocolate, chocolate 
liquor, chocolate paste, bitter chocolate coating, is the solid plastic 
mass obtained by grinding cacao nibs without the removal of fat 
or other constituents except the germ, and contains not less than 
fifty per cent (50%) cacao fat and, on the moisture and fat-free 



818 Definitions and Standards 

basis, not more than eight and five-tenths per cent (8.5%) total 
ash, not more than four-tenths per cent (0.4%) ash insoluble in 
hydrochcloric acid, not more than five and six-tenths per cent 
(5.6%) ash insoluble in Avater, not more than seven per cent (1%) 
crude fiber, not more than four per cent (4%) cacao shell. 

4. Sweet chocolate, sweet chocolate coating, is chocolate 
mixed with sugar (sucrose), with or without the addition of cocoa 
butter, spices, or other flavoring material, and contains on the 
moisture, sugar and fat-free basis, no higher percentage of total 
ash, ash insoluble in hyrochloric acid, ash insoluble in water, 
crude fiber, or cacao shell, respectively, than is found in the 
moisture and fat-free residue of chocolate. 

5. Cocoa, powdered cocoa, is chocolate deprived of a portion 
of its fat and finely pulverized and contains not less than twenty 
per cent (20%) cacao fat and, on the moisture and fat-free basis, 
no higher percentage of total ash, ash insoluble in hydrochloric 
acid, ash insoluble in water, crude fiber, or cacao shell, respec- 
tively, than is found in the moisture and fat-free residue of 
chocolate. 

6. Sweet cocoa, sweetened cocoa, is cocoa mixed with sugar 
(sucrose), and contains not more than sixty per cent (60%) 
sugar in the finished product, and, on the moisture, sugar and 
fat-free basis, no higher percentage of total ash, ash insoluble in 
hydrochloric acid, ash insoluble in water, crude fiber, or cacao 
shell respectively, than is found in the moisture and fat-free 
residue of chocolate. 

7. Milk chocolate, milk cocoa, sweet milk chocolate, and 
sweet milk cocoa, are chocolate, cocoa, sweet chocolate, and sweet 
cocoa, respectively, to which milk has been added in the course of 
their preparation and which contain not less than twelve per 
cent (12%) of whole milk solids in the finished product. 

Flavoring Extracts. — 1. A flavoring extract is a solution in 
ethyl alcohol of proper strength of the sapid and odorous prin- 
ciples drived from an aromatic plant, or parts of the plant, with or 
without its coloring matter, and conforms in name to the plant 
used in its preparation. 

2. Almond extract is the flavoring extract prepared from oil 
of bitter almonds, free from hydrocyanic acid, and contains not 
less than one per cent (1%) by volume of oil of bitter almonds. 



Extracts 819 

2a. Oil of bitter almonds, commercial, is the volatile oil ob- 
tained from the seed of the bitter almond (Amygdalus communis 
L.), the apricot (Primus armeniaca L,), or the peach (Amygdalus 
persica L.). 

3. Anise extract is the flavoring extract prepared from oil of 
anise, and contains not less than three per cent (3%) of oil of 
anise. 

3a. Oil of anise is the volatile oil obtained from the anise seed. 

4. Celery seed extract is the flavoring extract prepared from 
celery seed or the oil of celery seed, or both, and contains not less 
than three-tenths per cent (0.3%) by volume of oil of celery seed. 

4a. Oil of celery seed is the volatile oil obtained from celery 
seed. 

5. Cassia extract is the flavoring extract prepared from oil 
of cassia, and contains not less than two per cent (2%) by volume 
of oil of cassia. 

5a. Oil of cassia is the lead-free volatile oil obtained from the 
leaves or bark of Cinnamomum cassia Bl. and contains not less 
than seventy-five per cent (75%) by weight of cinnamic aldehyde. 

6. Cinnamon extract is the flavoring extract prepared from 
oil of cinnamon, and contains not less than two per cent (2%) by 
volume of oil of cinnamon. 

6a. Oil of cinnamon is the lead-free volatile oil obtained 
from the bark of the Ceylon cinnamon (Cinnamomum zeylanicum 
Breyne), and contains not less than sixty-five per cent (65%) by 
weight of cinnamic aldehyde and not more than ten per cent 
(10%) by weight of eugenal. 

7. Clove extract is the flavoring extract prepared from oil 
of cloves, and contains not less than two per cent (2%) by volume 
of oil of cloves. 

7a. Oil of cloves is the lead-free, volatile oil obtained from 
cloves. 

8. Ginger extract is the flavoring extract prepared from 
ginger, and contains in each one hundred (100) cubic centimeters 
the alcohol-soluble matters from not less than twenty (20) grams 
of ginger. 

9. Lemon extract is the flavoring extract prepared from oil 
of lemon or from lemon peel, or both, and contains not less than 
five per cent (5%) by volume of oil of lemon. 



820 Definitions and Standards 

9a. Oil of lemon is the volatile oil obtained, by expression or 
alcoholic solution, from the fresh peel of the lemon (Citrus Limo- 
mum L.), has an optical rotation (25° C.) of not less than +60° 
in a 100-millimeter tube, and contains not less than four per cent 
(4%) by weight of citral. 

10. Terpeneless extract of lemon is the flavoring extract 
prepared by shaking oil of lemon with dilute alcohol, or by dis- 
solving terpeneless oil of lemon in dilute alcohol, and contains 
not less than two-tenths per cent (0.2%) by weight of citral de- 
rived from oil of lemon. 

10a. Terpeneless oil of lemon is oil of lemon from which all 
or nearly all of the terpens have been removed. 

11. Nutmeg extract is the flavoring extract prepared from oil 
of nutmeg, and contains not less than two per cent (2%) by 
volume of oil of nutmeg. 

11a. Oil of nutmeg is the volatile oil obtained from nutmegs. 

12. Orange extract is the flavoring extract prepared from 
oil of orange, or from orange peel, or both, and contains not less 
than five per cent (5%) by volume of oil of orange. 

12a. Oil of orange is the volatile oil obtained, by expression 
or alcoholic solution, from the fresh peel of the orange (Citrus 
aurantium L.), and has an optical rotation (25°C.) of not less 
than +95° in a 100-millimeter tube. 

13. Terpeneless extract of orange is the flavoring extract 
prepared b}^ shaking oil of orange with dilute alcohol, or by 
dissolving terpeneless oil of orange in dilute alcohol, and corre- 
sponds in flavoring strength to orange extract. 

13a. Terpeneless oil of orange is oil of orange from which all 
or nearly all of the terpenes have been removed. 

14. Peppermint extract is the flavoring extract prepared 
from oil of peppermint, or from peppermint, or both, and contains 
not less than three per cent (3%) by volume of oil of peppermint. 

14a. Peppermint is the leaves and flowering tops of Mentha 
piperita L. 

14b. Oil of peppermint is the volatile oil obtained from 
pepperment, and contains not less than fifty per cent (50%) by 
weight of menthol. 



Extracts 821 

15. Rose extract is the flavoring extract prepared from otto 
of roses, with or withoiit red rose petals, and contains not less 
tlian four-tenths per cent (0.4%) by volume of otto of roses. 

15a. Otto of roses is the volatile oil obtained from the petals 
of Rosa damaseent Mill., R. centrifolia L., or R. moschata Herrm. 

16. Savory extract is the flavoring extract prepared from oil 
of savory, or from savory, or both, and contains not less than 
thirty-five hundredths per cent (0.35%) by volume of oil of 
savory. 

16a. Oil of savory is the volatile oil obtained from savory. 

17. Spearmint extract is the flavoring extract prepared from 
oil of spearmint, or from spearmint, or both, and contains not 
less than three per cent (3%) by volume of oil of spearmint. 

17a. Spearmint is the leaves and flowerings tops of Mentha 
spicata L. 

17b. Oil of spearmint is the volatile oil obtained from spear- 
mint. 

18. Star anise extract is the flavoring extract prepared from 
oil of star anise, and contains not less than three per cent (3%) 
by volume of oil of star anise. 

18a. Ojl of star anise is the volatile oil distilled from the 
fruit of the star anise (Illicium verum Hook). 

19. Sweet basil extract is the flavoring extract prepared 
from oil of sweet basil, or from sweet basil, or both, and contains 
not less than one-tenth per cent (0.1%) by volume of oil of sweet 
basil. 

19a. Sweet basil is the leaves and tops of Ocymum basili- 
cum L. 

19b. Oil of sweet basil is the volatile oil obtained from basil. 

20. Sweet marjoram extract, marjoram extract, is the flavor- 
ing extract prepared from the oil of marjoram, or from marjoram, 
or both, and contains not less than one per cent (1%) by volume 
of oil of marjoram. 

20a. Oil of marjoram is the volatile oil obtained from 
marjoram. 

21. Thyme extract is the flavoring extract prepared from oil 
of thyme, or from thyme, or both, and contains not less than two- 
tenths per cent (0.2%) by volume of oil of thyme. 



822 Dkfinitions and 5>tandards 

21a. Oil of thyme is the volatile oil obtained from thyme. 

22. Tonka extract is the flavoring extract prepared from 
tonka bean, with or without sugar or glycerin, and contains not 
less than one-tenth per cent (0.1%) by weight of coumarin 
extracted from the tonka bean, together with a corresponding 
proportion of the other soluble matters thereof. 

22a, Tonka bean is the seed of Coumarouna adorata Abulet 
(I^ipteryx odorata (Aubl.). Willd.) 

23. Vanilla extract is the flavoring extract prepared from 
vanilla bean, with or without sugar or glycerin, and contains in 
one hundred (100) cubic centimeters the soluble matters from 
not less than ten (10) grams of the vanilla bean. 

23a. Vanilla bean is the dried, cured fruit of Vanilla plani- 
folia Andrews. 

24. Wintergreen extract is the flavoring extract prepared 
from oil of wintergreen, and contains not less than three per cent 
(3%) by volume of oil of wintergreen. 

24a. Oil of wintergreen is the volatile oil distilled from the 
leaves of the Gaultheria procumbens L. 

The state and territorial standards prevailing, as far as could 
be ascertained at time of going to press, are given in Table 151. 
This table follows closely the legal standards for dairy products 
issued May 1st, 1916, by the U. S. Department of Agriculture, 
and which was subsequently revised by Taylor and Thomas.- 
Numerous further revisions have been made, based upon informa- 
tion contained in letters or circulars obtained at original sources. 
In a few instances it has been found impossible to obtain any con- 
firmatory information. 

STATE BACTERIA STANDARDS. 

The only states that have adopted bacteria standards are 
the following : 

California. — In milk as Note (1) ; cream as Note (2). 

Connecticut. — In milk 100,000 per cc, in cream 5,000,000 per 
cc. After pasteurizing in milk 50,000 per cc, in cream 100,000 
per ee. 

Delaware.— In milk, 100,000 per cc, Cream as Note (7). 

Georgia. — In milk 500,000 per cc 



BACTIiKlA 823 

Hawaii. — In milk, 1,000,000 per ce. 
Idaho. — In milk 500,000 per cc, cream, 500,000 ec. 
Montana. — In milk or ice cream, 500,000 per cc. 
New Hampshire. — In milk, 500,000 per cc. 
New York. — In milk and cream as Note (13). 
Oklahoma. — In milk as Note (16). 
Porto Rico.— In milk, 100,000 per cc. 
Vermont. — In milk, 200,000 per cc. 
Washington. — In milk, 400,000 per cc. 

STANDARDIZATION OF PASTEURIZATION— TIME AND 
TEMPERATURES. 

The States that have established control of pasteurization and 
the standards adopted are as follows : — 

Arizona. — 145° F, for 30 minutes. 
California.— 140-145° F. for 25 minutes. (5). 
Connecticut.— 142-148 °F. for 30 minutes. 
Delaware.— 145° F. for 30 minutes. 

Indiana.— 145° F. for 30 minutes or 160° F. for 30 seconds. (9). 
Iowa. — 145° F. for 30 minutes. 
Louisiana. — 140° F. for 20 minutes. 
Massachusetts. — 140-145° F. for 30 minutes. 
Michigan.— 145° F. for 30 minutes or 185° flash. 
Minnesota.— 145° F. for 30 minutes or 180° flasli. 
Montana. — 140-145° F. for 30 minutes. 
Nebraska. — (5). 

New Jersey.— 142-145° F. for 30 minutes. 
Nevada. — 140° F. for 25 minutes or 170° F. flash method. 
New York.— 142-145° F. for 30 minutes. 

Oklahoma. — 145° F. for 25 minutes, or 150° F. for 20 minutes, 
or 170° F., flash method. 

Oregon.— 140° F. for 30 minutes (5). 

Tennessee. — 145° F. for 30 minutes or 165° F. for 30 seconds. 

Vermont. — 145° F. for 30 minutes. 

Washington. — 140° F. for 25 minutes. 

Wyoming. — 145° F. for 30 minutes or 165° for 30 seconds. 

These standards Avere established in the manner indicated 
under the heading "Standards Established by" in the tables. 



824 



Definitions and Standards 



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Act of legislature. 
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State Board of Health u 
lative authority. 


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of federal standards. 
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lative authority. 
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p'artment under 

authority. 
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legislative authority. 
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Standard Commissi 

legislative authority. 
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of Health under legis 

thority. 
By act of legislature s 

and Food Commiss 

legislative authority. 
State Board of Heal 

legislative authority. 




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826 



Definitions and Standards 





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Notes 827 

NOTES 

(1). Grade A. — raw— less than 100,000 bacteria per cc. 

Grade A — pasteurized — less than 200,000 bacteria per cc. before 

pasteurization: less than 15,000 after pasteurization. 
Grade B — less than 1 million bacteria per cc. before pasteurization; 

less than 50,000 after pasteurization. 

(2). Not more than two times the bacteria in the corresponding grade 

of milk. 
(3). U. S. Department of Agriculture Standards. 
(4). Half skim, 25 per cent fat. 
(5). Unless milk is from herds free from tuberculosis as evidenced by 

the tuberculin test. 
(6). Less than 50 per cent of total solids. 
(7). Raw cream — less than 500,000 bacteria per cc. Pasteurized cream — 

less than 250,000 bacteria per cc. 
(S). Bacteria standard for milk and ice cream is 500,000 per cc. 
(9). Compulsory pasteurization of milk products entering into the manu- 
facture of ice cream. 
(10). Fruit ice cream, 4 per cent fat: nut ice cream, 6 per cent fat. 
(11). Skim-milk from creameries required to be pasteurized to 180° F. 
(12). "By terms of law enacted in 1917. provision is made for the sale of 

milk, provided that such be 'pure natural milk' and that 'every 

can, bottle, or other container in which such milk is shipped, sold 

or delivered, at wholesale or retail, is plainly labeled so as to show 

its guaranteed composition.' " 
(13). Grade A, Raw: 

Milk — not more than 60.000 bacteria per cc. 

Cream — not more than 300,000 bacteria per cc. 

Grade A, pasteurized: (Milk or cream before pasteurization not 

more than 200,000 bacteria per cc") 

Milk — not more than 30,000 bacteria per cc. 

Cream — not more than 150,000 bacteria per cc. 

(Irrade B, raw: 

Milk — not more than 200.000 bacteria per cc. 

Cream — not more than 750.000 bacteria per cc. 

Grade B, pasteurized: (Milk or cream before pasteurization, no 

more than 1,500,000 bacteria per cc. ) 

Milk — not more than 100,000 bacteria per cc. 

Cream — not more than 500,000 bacteria per cc. 
(14). Cheese made from skimmed or partially skimmed milk must be 

branded with the words, "Skim-milk Cheese:" if it contains 13 per 

cent milk fat or over, it may be branded, "Medium Skim-milk 

Cheese." or if it contains IS per cent of milk fat or over, it may be 

bi-anded "Special Skim-milk Cheese." 
(15). Milk falling under the standard for whole milk shall be termed 

skim-milk. 
(16). "Bottled raw milk must not contain more than 100.000 bacteria from 

May 1 until Oct. 1. All pasteurized bottled milk not more than 

50,000 in the same period of time." 
(17). "All milk and cream used in manufacture of creamery butter and 

ice cream for commercial purposes, and all milk bought to be resold, 

must be pasteurized." 
(IS). "If a person accused of violating section one of this act shall furnish 

satisfactory affidavit that nothing has been added to or taken from 

the milk in question, which is otherwise pure and wholesome, and is 

not below three (3) per centum of butterfat. ... no prosecution 

shall be instituted against said person." 
(19). Cheese — full cream, not less than 32 per cent butter fat. Three 

fourth cream not less than 24 per cent butterfat. One-half cream 

not less than 16 per cent butter fat. One-fourth cream not less than 

S per cent butter fat. Skimmed — less than 8 per cent butter fat. 
^20). Cheese — half skim not less than 25 per cent butter fat, and quarter 

skim not less than 12 per cent butter fat, in the water-free substance. 
(21). TTnited States standards followed upon products not specified in 

State laws. 
(22). Ice milk (frozen) 2.40 per cent fat and .60 per cent gelatin. 



828 



Dkfinitions and Standards 



NOTE S — (Continued) 

(23). Composition is to be indicated upon the label, in the case of evapo- 
rated milk. 

(24). No state standards. Nearly all incorporated municipalities control 
sale of dairy products by ordinance. 

(25). Ice cream to contain not less than 20 per cent milk solids, and to 
weigh not less than 4.75 lbs. pv^r gallon. 

(26). Plain ice cream to contain not less than 18 per cent of milk solids. 
Fruit ice cream not less than 15 per cent of milk solids. 

(27). Ice cream to contain 32.5 per cent total solids. 

(28). Ice cream to contain not less than 18.00 per cent milk solids. 

(29) Milk for making butter, cheese and condensed milk may contain 
3.0 per cent fat. 

(30). Ice cream to contain not less than 30 per cent of total solids. 

(31). Data given not confirmed at original sources. 

(32). No state standards upon dairy products, excepting oleomargarine. 



STATISTICS ON MILK AND CREAM REGULATIONS IN CITIES 

AND TOWNS. 

In 1916 a committee from the Official Dairy Instructors' Asso- 
ciation" made a study of the milk and cream regulations in 694 
cities and towns in the United States The cities were classified 
into four groups according to population and studies were made 
of the various regulations. Some of the information obtained is 
shown in detail in Table 152 to 172 as follows : 



TABLE 152. 
Grouping of Cities and Regulations Available for Study. 



Number of cities and towns represented in this 
survey. 

Number of cities and towns reporting no regula- 
tions 

Number of cities and towns from which partial 
regulations were available 

Niunber of complete regulations of cities and 
towns represented 





POPULATION 






oo 


5o 
§1 


CO. 

Oo 


511 


133 


42 


8 


218 


5 








69 


3 








234 


125 


42 


8 



TOTAL 
CITIES 



694 



223 



62 



409 



Composition Regulations 



829 



TABLE 153. 
Regulations' Relating to Water. 



Number of regulations limiting percentage of 

water 

Number of regulations not referring to per- 
centage of water 

Number of regulations limiting water content 
of milk to 

89.00 per cent 

88.51 per cent 

88.50 per cent 

88.25 per cent 

88.00 per cent 

87.51 per cent 

87.50 per cent 

87.05 per cent 

87.00 per cent 

80.50 per cent 

80.00 per cent 

8.00 per cent 



POPtJI/ATION 



2o 
8° 



79 
155 



1 

3 
2 

44 
1 

12 


12 
1 
2 
1 




11 

2 
29 
2 
4 
1 
3 

1 




21 
21 



1 

2 

1 

12 

3 

2 






TOTAL 
aTIES 



160 
249 



2 

11 
7 
5 

89 
3 

20 
1 

17 
1 
3 
1 



TABLE 154. 
Regulations Relating to Total Solids. 



minimum 



Number of regulations requiring 
percentage of total solids 

Number of regulations not referring to per- 
centage of total solids 



106 

128 



60 
65 



25 

17 



198 
211 



Number of regulations having or calling for 

13.00 per cent total solids 

12.51 per cent total solids 

12.50 per cent total solids 

12.15 per cent total solids 

12.00 per cent total solids 

11.75 per cent total Solids 

11.50 per cent total solids 

11.00 per cent total solids 

10.50 per cent total solids 



POPULATION 



em 



13 
2 

15 
6 

59 
2 
7 
I 
1 



2 
2 
1 
2 
46 
2 
5 





1 
3 

15 
1 
3 





OS 



TOTAL 

orriEs 



17 
5 

20 

8 

124 

5 

17 
1 
1 



830 



Definitions and Standards 



TABLE 155. 
Regulations Relating to Solids Not Fat. 



POPULATION 



11 



il 



6s 



TOTAl 

ciTisa 



Number of regulations calling for minimum 

percentage of solids not fat 

Number of regulations not referring to per- 
centage of solids not fat 

Number of regulations calling for 

10.50 per cent solids not fat 

9.50 per cent solids not fat 

9.25 per cent solids not fat 

9.00 per cent solids not fat 

8.75 per cent solids not fat 

8.50 per cent solids not fat 

8.25 per cent solids not fat 

8.00 per cent solids not fat 



38 


24 


16 


1 


198 


103 


26 


7 





1 








1 


1 











1 








6 


2 


1 





1 


2 


4 





28 


14 


11 


1 





1 








2 


2 









79 

334 

1 
2 
1 
9 
7 
54 
1 
4 



TABLE 156. 
Regulations Relating to Fat in Milk. 



Number of regulations requiring a minimum 
percentage of fat 

Number of regulations not referring to percent- 
age of fat 

Number of regulations calling for 

4.00 per cent fat 



3.70 per cent fat 

3.60 per cent fat 

3 51 per cent fat 

3.50 per cent fat 

3.40 per cent fat 

3.35 per cent fat 

IN umber ol regulations calling for 

3.30 per cent fat 

3.25 per cent fat 

3.20 per cent fat 

3.00 per cent fat 

2.50 per cent fat 



137 

97 


2 
2 

35 
3 




20 


67 





81 

44 



1 
1 
10 

1 

2 

1 
19 

2 
43 

1 



32 

10 

1 

1 
1 

7 
1 



6 
2 
12 
1 



257 

152 

1 
2 
4 
2 

53 
5 

10 

1 

46 

4 

127 

2 



Bacteria Regulations 



831 



TABLE 157. Regulations Relating to Bacteria in Milk 



Number of regulations having a legal limit for 

bacteria in milk 

Number of regulations not referring to bacterial 

limits 

Number of regulations having a numerical 

limit for bacteria of 

50,000 per cubic centimeter 

100,000 per cubic centimeter 

150,000 per cubic centimeter 

200,000 per cubic centimeter 

250,000 per cubic centimeter 

300,000 per cubic centimeter 

350,000 per cubic centimeter 





POPULATION 






5g 


o 

si 

oo 

8^ 


o 

II 


95 


66 


24 


4 


139 


59 


IS 


4 


1 


1 








21 


11 


3 





1 


3 


1 





6 


7 


4 





7 


4 


2 





7 


10 


2 


















TOTAL 
CITIES 



189 
220 



2 
35 

5 
17 
13 
19 





TABLE 158. Regulations Relating to Fat in Cream. 

Number of regulations requiring a minimum 

percentage of fat 

Number of regulations not referring to percent 

age of fat 

Number of regulations calling for 

25.0 per cent fat 



22.0 per cent fat. 
20.0 per cent fat. 
19.0 per cent fat. 
18.0 per cent fat. 
17.5 per cent fat. 
16.0 per cent fat. 
15.0 per cent fat. 
14.0 per cent fat. 
10.0 per cent fat. 



87 


49 


20 


5 


147 


76 


22 


3 


3 


1 








1 











13 


3 


5 





1 











42 


29 


12 


2 


1 











10 


6 


3 





13 


10 





3 


2 











1 












161 

248 

4 
1 

21 
1 

85 
1 

19 

26 
2 
1 



TABLE 169. Regulations Relating to Tuberculin Test. 



Number of regulations specifying that cows 

Be tuberculin tested 

Be tested once a year 

Be tested once in two years 

Be tested twice a year 

Be tested at discretion of inspector. . . . 



POPULATION 


O^ 


S^ 


o 






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8= 

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gg 




53 


21 


21 


3 


20 


16 


14 





2 


1 











1 














1 






TOTAL 
CTTIK8 



98 

50 

3 

1 

1 



832 



Definitions and Standards 



TABLE 160. 
Regulations Relating to Bacteria in Cream. 



Number of regulations having a numerical 
limit for bacteria of: 

400,000 per cubic centimeter 

500,000 per cubic centimeter 

1,000,000 per cubic centimeter 

5,000,000 per cubic centimeter 

Number of regulations having a legal limit for 

bacteria in cream 

Number of regulations not referring to bacterial 

limits in cream 

Number of regulations having a numerical 
limit for bacteria of 

50,000 per cubic centimeter 

100,000 per cubic centimeter 

150,000 per cubic centimeter 

200,000 per cubic centimeter 

250,000 per cubic centimeter 

300,000 per cubic centimeter 

350,000 per cubic centimeter 

500,000 per cubic centimeter 

800,000 per cubic centimeter 

1,000,000 per cubic centimeter 





POPULATION 










s 




TOlAl 








.H 


CITIES 


i« 


§8 


io 


oS 




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8" 






1 


1 


1 





3 


49 


27 


11 


2 


89 


2 


2 





1 


5 











1 


1 


7 


15 


8 





30 


227 


110 


34 


8 


379 


1 











1 





1 








1 





1 








1 


1 


1 








2 




















1 


2 





3 





1 








1 


1 


4 


5 





10 


1 











1 


3 


6 


1 





10 



TABLE 161. 
Regulations Relating to Temperature. 





POPULATION 






2o 


o 
5 2 


o 


Oo 


TOTAL 
CITIICS 


Number of regulations calling for a temperature 
not higher than 

65° F 


6 



27 



1 

12 

46 

1 


1 

2 

19 

1 



13 

36 




2 


11 


2 

15 






1 




5 

1 


9 


63° F 


2 


60° F 


58 


58° F 


1 


56° F 


1 


65° F 


27 


50° F 


102 


45° F 


2 







4 



Specific Gravity Rrgulations 



833 



TABLE 162. Regulations Relating to Specific Gravity. 



Number of regulations prescribing a minimum 

specific gravity 

Number of regulations requiring a specific 
gravity of 

1030.0 

1029.0 

10.29 

1.030 

1.029-1.033 

1.029 

1.028 

1.027 



POPULATION 



s.g 



31 



2 
4 
2 
1 

20 
1 
1 



ii 

gS 



TOTAIi 

cmxs 



38 



2 
4 
2 
2 
3 
23 
1 
1 



TABLE 163. Regulations Relating 


to Water 


Supply. 






POPtn,ATlON 






o^ 


2o 

oS 


o 
go 

li 


s-g 


TOTAL 
CITIES 


Number of regulations requiring that water 
supply be 

Clean 


70 

23 

7 

29 

54 





.0 


26 
3 

14 
30 
6 
1 
1 


11 

4 
4 
9 
12 
8 







1 
1 

2 





107 


Fresh 


30 




12 


Abundant 


53 


Free from contamination 


98 


Pure 


14 


Well chosen 


1 


Suitable 


1 







TABLE 164. Regulations Relating to Milkers. 



Number of regulations requiring that 

Milker be free from disease 

Milker be clean 

Milker wear clean clothes 

Milker wash hands before milking 

Milker brush nails before milking 

Milking be done with clean dry hands 
Hands be not wet during milking 





POPULATION 




2o 




2o 
gg 

oo 


feg 


109 


54 


22 


5 


78 


40 


13 





61 


34 


12 


1 


52 


41 


16 


2 


8 


4 


2 





46 


22 


10 


1 


12 


22 


4 






TOTAL 
CITIES 



190 

131 

108 

111 

14 

79 

38 



834 



DliFlNITIONS AND STANDARDS 



TABLE 165. 
Conditions Which Render Milk Legally Unsalable. 





POPULATION 










o 


1} 


TOTAL 
CITIES 


Number of regulations which forbid the sale 
of milk under conditions stated below 

Number of regulations which do not mention 
when milk is unsalable 


234 



160 
67 
46 

79 


115 

10 

85 
36 
29 

43 


39 

3 

34 

12 

6 

20 


8 



8 


1 

2 


396 

13 

2S7 


Number of regulations which mention 

Diseased cows 


Cows kept in filthy quarters 


ILS 


Milk containing visible dirt 


82 


Cows kept in crowded and unhealthy 
stable 


144 







Number of regulations which mention 

Sediment 

Sour 

Sophisticated 

Mouldy - 

Decayed ; . 

Acid plus 2 

Garget 

Abnormal 

Unnatural 

Bitter , 

Decomposed 

Glucose 

Garlic 

Unhealthy 

Stringy 

Cabbage 

Slimy 

Sugar waste 





POPULATION 




o_ 


Sr. 


5„ 




it 


oS 

go 


m 




in"^ 


in'^ 


o ■" 




1 





1 





1 











1 











1 


2 








3 











1 


6 


1 





1 











3 














1 


2 








1 











1 











3 











1 











9 


4 








2 


2 








2 














2 


1 








1 






TOTAL 
CITIES 



2 

1 

1 

3 
3 
8 
1 
3 
3 
1 
1 
3 
1 
13 
4 
2 
3 
1 



Milk Regulations 
TABLE 165— Continued. 



835 



Number of regulations which mention 

Milk when adulterated 

When cows are fed distillers' grains. . . 

When cows are fed swill 

From cows a certain number of days before 

calving 

From cows a certain number of days after 

calving 

Foreign substance in milk 

Putrefactive feeds 

Feeds unwholesome 

Feeds impure 

Milk unclean 

Cows fed on refuse 

Cows fed garbage 

Cows fed wet brewers' grains 

Cows given contaminated water 

Cows fed vinegar waste 

Pus in milk 

Cows fed beet pulp 

Cows fed turnips 

Cows fed starch waste 

Diseased cows. 

Insanitary foods 

Frozen foods 

Ropy milk 

Bloody milk 

Milk above legal limits in bacteria 

Milk above legal limits in temperature. 

Improper milk 

Watered 

Diluted 

Silage 

Unsound 

Tainted 

Musty 

Insects 

Hairs 

Flies 





POPITLATION 




2o 


5§ 


o 
go 

m 


Oo 


150 


77 


30 


3 


59 


42 


17 


7 


58 


41 


14 


3 


139 


86 


27 


6 


138 


89 


27 


6 


107 


65 


28 


5 


57 


38 


21 


4 


73 


50 


22 





47 


38 


10 





23 


16 


5 





41 


28 


9 


2 


34 


34 


13 


3 


32 


22 


12 


2 


19 


10 


18 


3 


6 


6 


6 





8 


4 


1 





5 


1 








2 


2 








8 


4 








1 


2 








1 











1 











8 


6 








14 


11 


4 


1 


94 


18 








139 


44 


2 





2 


4 


3 





1 











3 











1 


1 








1 











1 


1 


1 





1 











1 











1 











1 












TOTAL 
CITIES 



260 

125 
116 

258 

260 

205 

120 

145 

95 

44 

80 

84 

68 

50 

18 

13 

6 

4 

12 

3 

1 

1 

14 

30 

112 

185 

9 

1 

3 

2 

1 

3 

1 

1 

1 

1 



836 



Definitions and Standards 



TABLE 166. 

Regulations in Regard to Parturition. 



Number of regulations providing for a specific 
number of days before and after parturition 

that the milk cannot be used 

Number of regulations which do not cover this 

point 

Number of regulations prohibiting the sale of 
milk 

60 days before parturition 

45 days before parturition 

42 days before parturition 

40 days before parturition 

30 days before parturition 

21 days before parturition 

20 days before parturition 

15 days before parturition 

14 days before parturition 

12 days before parturition 

10 days before parturition 

8 days before parturition 

4 days before parturition 

Number of regulations prohibiting the sale of 

milk 

21 days after parturition 

15 days after parturition 

12 days after parturition 

10 days after parturition 

9 days after parturition 

8 days after parturition 

7 days after parturition 

6 day* after parturition 

5 days after parturition 

4 days after parturition 

3 days after parturition 



POPULATION 



139 
95 



4 

1 





19 

6 

11 

89 

4 



1 

4 





1 
5 
7 

28 
3 
4 

10 
4 

72 
3 
1 



89 
36 





1 
1 
3 
5 
7 

63 
1 
1 
2 
1 
1 




3 

7 
12 
2 

8 
3 
52 
2 




27 
15 







1 

3 
23 









1 
3 
5 

1 
2 
2 
13 





TOTAL 
CITIXS 



261 
148 



4 

1 

1 

1 

23 

11 

21 

180 

5 

1 

4 

5 

1 



1 

9 

17 

46 

5 

5 

21 

10 

140 

5 

1 



Milk House Regulations 

TABLE 167, 
Regulations Relating to Milk House. 



83; 



milk 



Number of regulations requiring that milk 
houses be 

Clean 

Used for no other purpose 

Have tight sound floor 

Be well ventilated 

Be well lighted 

Be well drained 

Number of regulations requiring sterilizing 

equipment in the milk house 
Number of regulations requiring that 
house be 

Well screened ! 

Provided with suitable racks 

Provided with cooling tanks 

Located a certain distance from the stable 

Number of regulations requiring milk house to 

be located 

100 feet from stable 

50 feet from stable 

40 feet from stable 

25 feet from stable , 

20 feet from stable , 

15 feet from stable 

12 feet from stable 



Number of regulations requiring milk house to 

be located 

10 feet from stable 

Away from stable 

At a distance from stable 

With an air space between milk house 
and stable 

Apart 

Distance not given 

Number of regulations requring that 

Milk house be free from odors 

No swine be within a stated distance .... 

No swine be within 100 feet 

No swine be within 50 feet 

Swine be "not near" 



132 
82 
46 
62 
51 
36 

13 



63 
5 
8 

45 



1 

28 
2 

1 
1 
1 

52 
27 

1 
26 





LATION 




O 

■*^ o 

p 


So 

o§ 


22 


3 


19 


3 


13 


1 


11 


1 


11 


1 


14 


1 


2 





16 


2 


6 





5 


1 


11 











1 











1 

















1 









1 





10 


2 























3 








1 


5 





22 


6 





7 





1 























1 






TOTAL 
CITIES 



232 

150 

87 

101 

87 

71 

31 



125 
15 
26 

71 



2 

40 

2 

1 
4 

7 

80 

35 

1 

26 
1 



838 



Definitions and Standards 
TABLE 167— Continued. 



POPULATION 



5g 



O) o 

o§ 



Number of regulations requiring that milk house 

Be a separate room 

Be a distance from privy 

300 feet from privy 

200 feet from privy 

100 feet from privy 

75 feet from privy 

50 feet from privy 

40 feet from privy 

25 feet from privy 

15 feet from privy 

10 feet from privy 

Away from privy 

Not near privy 

Distant 

Not mentioned 



74 


48 


26 


3 


56 


40 


13 


1 





1 








1 











2 


3 


1 











1 





4 


1 


1 


1 


2 











2 


3 








2 


3 














1 





16 


18 








6 


1 








21 














10 


9 






TOTAL 
aTIES 



151 

110 

1 

1 

6 

1 

7 

2 

5 

5 

1 

34 

7 

21 

19 



TABLE 168. Regulations Relating to Milk Utensils. 





POPULATION 








2o 


o 

So 

2"^ 


O 

o o 


TOTAL 
CITIES 


Number of regulations requiring that only 
round cornered utensils be used 


6 

5 

36 

30 


5 

4 

15 

17 




7 

7 

14 



3 

1 


11 


Number of regulations requiring that only 


19 


Number of regulations requiring that utensils 


58 


Number of regulations requiring that utensils 
be well constructed 


62 







Number of regulations requiring that utensils be 

clean 

Washed 

Scalded 

Sterilized 

Used for no other purpose 

Protected from contamination 

Number of regulations represented in the above 

items 

Number of regulations containing nothing re- 
garding the cleaning of utenlils 



112 


71 


22 


1 


94 


52 


17 


2 


48 


28 


14 


3 


121 


73 


25 


7 


56 


33 


17 


3 


52 


51 


16 


1 


184 


114 


37 


7 




11 


5 


1 



206 
165 
93 
226 
109 
120 

342 

67 



Milk Plant Regulations 



839 



TABLE 169. Regulations Relating to City Milk Plants. 



Number of regulations requiring that milk plant 
shall 

Be well lighted 

Be well ventilated 

Be well screened 

Be well drained 

Be properly constructed 

Be properly equipped 

Be clean 

Be free from flies 

Be free from odors 

Be free from contamination 

Have sewer connections 

Have facilities for cleaning utensils in 

plant 

Have facilities for storing milk in plant. . . . 

Have running hot and cold water 

Have separate room for handling milk. . . 

Have tight walls and ceilings 

Have tight floors 

Score a certain number of points 

Shall score not less than 

40 points 

50 points 

60 points 

70 points 

75 points 

not mentioned 





POPULATION 






oS 


2o 

si 




l| 


TOTAt 

cmsa 


9 


8 


7 


2 


26 


6 


7 


6 


2 


21 


10 


18 


6 


1 


35 


7 


8 


6 


2 


23 


2 


7 


5 


2 


16 


8 


6 


8 





22 


19 


27 


19 


5 


70 


5 


1 


2 


2 


10 


4 


1 


2 


1 


8 


2 


3 


1 


2 


8 


2 


3 


2 





7 


2 


5 


5 


3 


15 


3 


2 





2 


7 


2 


5 


1 


1 


9 


4 


2 


5 


1 


12 


2 


5 


6 


1 


14 


9 


7 


7 


2 


25 


5 


5 


3 





13 





1 








1 


1 


1 








2 





1 


1 





2 


2 


2 


1 





5 








1 





1 


2 











2 



TABLE 170. Regulations Relating to Delivery Wagons. 



POPULATION 




li- 


o 


o 
o 


oS 


no 


53 


14 





42 


30 


12 


1 


88 


52 


15 


3 


61 


41 


14 





112 


78 


23 


4 


123 


74 


29 


6 



TOTAL 

aTIBS 



Number of regulations requiring 

Drivers to be free from disease 

Wagons to be covered 

Wagons to be clean 

Wagons not to haul refuse or be used for 

any other purpose 

Name of dealer to appear on wagon. . . 
Number of license to appear on wagon 



177 

85 

158 

116 
217 
232 



840 DEFINITIONS AND STANDARDS 

TABLE 171. Regulations Relating to the Milk. 



POPULATION 



-g 

e©- 



TOTAL 
CITIES 



Number of regulations requiring that 

Milk be removed immediately from barn.. 

Milk be cooled immediately 

Milk be aerated 

Fore milk be discarded 

Milk must not be strained in barn 

Milk must be stored only in milk house. . . 

Milk be milked into covered pails 

Milk be graded 



89 

89 

23 

4 

4 

9 

20 




45 

61 

11 

6 

4 

33 

14 

5 



17 
18 
6 
6 
2 
6 



154 
171 
40 
17 
11 
48 
44 
9 



TABLE 172. Regulations Relating to the Scoiing of Dahy Faims. 





POPTTLATION 






-So 

i| 

U5 


5o 

O 


o 

§1 

Oo 


>5- 
oS 


TOTAL 

CITIES 


Minimum score of dairy farms 

80 


2 
1 
2 
8 

3 

3 
6 
1 


1 



12 
2 
1 

2 
4 






1 

3 

1 


1 









1 



1 








3 


75 


1 


65 , 


4 


60 


23 


55 


4 


50 


4 


46 -. 


1 


45 


6 


40 


10 


Not given 


1 







GRADING MILK AND CREAM. 

The old system of purchasing milk and cream by weight or 
measure with little attention being given to quality has been 
largely displaced in recent years by the adoption of methods 
which insure a higher price to the producer for rich milk or cream 
and for milk or cream of high sanitary quality. In order to apply 
this principle to the purchase of milk for the New York City 
supply the Board of Health of that city established different 
grades for both milk and cream and formulated regulations gov- 
erning distribution. 



Milk and Cream Regulations 841 

These regulations are given in detail as follows : 

"Regulations of the Department of Health of the City of New 
York Relative to the Grading of Milk and Cream. — Sec. 156. 

Milk and cream ; grades and designations, — All milk or cream 
held, kept, offered for sale, sold, or delivered in the City of New 
York shall be so held, kept, offered for sale, sold or delivered in 
accordance with the Regulations of the Board of Health and 
under any of the following grades or designations and not other- 
wise : 

' ' Grade A : For Infants and Children. ' ' 

1, Milk or cream (raw). 

2. Milk or cream (pasteurized). 
"Grade B: For Adults." 

1, Milk or cream (pasteurized). 
"Grade C. : For Cooking and Manufacturing Purposes Only." 

1, Milk or cream not conforming to the require- 

ments of any of the subdivisions of Grade A or 
Grade B, and which has been pasteurized ac- 
cording to the Regulations of the Board of 
Health or boiled for at least two (2) minutes. 

2. Condensed skimmed milk. 

The provisions of this section shall apply to milk or cream 
used for the purpose of producing or used in preparation of sour 
milk, buttermilk, homogenized milk, milk curds, sour cream, 
Smeteny, Kumyss, Matzoon, Zoolak, and other similar products 
or preparations, provided that any such product or preparation 
be held, kept, offered for sale, sold, or delivered in the City of 
New York. 

"Regulations Governing the Sale of Grade 'A' Milk or Cream 
(Raw). — Definition. — Grade 'A' milk or cream (raw) is milk or 
cream produced and handled in accordance with the Regulations 
as herein set forth. 

"Regulation 113. Tuberculin test and physical condition. — 
Only such animals shall be admitted to the herd as are in good 
physical condition, as shown by a thorough physical examination 
accompanied by a test with the diagnostic injection of tuberculin, 
within a period of one month previous to such admission. The test 



^42 DEFINITIONS AND STANDARDS 

is to be carried out as prescribed in the Regulations of the Depart- 
ment of Health governing the tuberculin testing of cattle. A chart 
recording the result of the official test must be in the possession 
of the Department of Health before the admission of any animal 
to the herd. 

"Regulation 114. Bacterial contents.— Grade 'A' milk 
(raw) shall not contain more than 60,000 bacteria per c. c. and 
cream more than 300,000 bacteria per c. c. when delivered to the 
consumer or at any time prior to such delivery. 

"Regulation 115. Scoring of dairies. — All dairies producing 
milk of this designation shall score at least 25 points on equip- 
ment and 50 points on methods, or a total score of 75 points on an 
official dairy score card approved by the Department of Health. 

"Regulation 116. Time of delivery. — Milk of this designation 
shall'be delivered to the consumer within 36 hours after produc- 
tion. 

Regulation 117. Bottling. — Milk or cream of this designation 
shall be delivered to the consumer only in bottles, unless other- 
wise specified in the permit. 

"Regulation 118. Labeling. — The caps of all bottles contain- 
ing Grade 'A' milk or cream (raw) shall be white, with the 
grade and designation 'Grade A (raw)' the name and address of 
the dealer, and the word 'certified' when authorized by the state 
law, clearly, legibly, and conspicuously displayed on the outer 
side thereof. No other word, statement, design, mark, or device 
shall appear on that part of the outer cap containing the grade 
and the designation unless authorized and permitted by the 
Department of Health. A proof print or sketch of such cap, 
showing the size and arrangement of the lettering thereon, shall 
be submitted to and approved by the said Department before 
being attached to any bottle containing milk or cream of the said 
grade and designation. 

"Additional Regulations Governing- the Sale of Grade 'A' 
Milk or Cream (Pasteurized). Definition. — Grade 'A' milk or 
cream (pasteurized) is milk or cream handled and sold by dealers 
holding permits therefor from the Board of Health, and produced 
and handled in accordance with the Regulations as herein set 
forth. 



Milk and Cream Rfx.uIvATions 843 

''Regulation 119. Physical exainiuation of cows. — All cows 
producing milk or cream of this designation must be healthy, as 
determined by a physical examination made annually by a duly 
licensed veterinarian. 

"Eegulation 120. Bacterial content. — Milk of this designation 
shall not contain more than 30,000 bacteria per c. c. and cream 
more than 150,000 bacteria per c. c. when delivered to the con- 
sumer or at any time after pasteurization and prior to such de- 
livery. No milk supply averaging more than 200,000 bacteria per 
c. c. shall be pasteurized to be sold under this designation. 

"Regulation 121. Scoring of dairies. — All dairies producing 
milk or cream of this designation shall score at least 25 points on 
equipment and 43 points on methods, or a total score of 68 points 
on an official score card approved by the Department of Health. 

"Regulation 122. Times of delivery. — Milk or cream of this 
designation shall be delivered within 36 hours after pasteuriza- 
tion. 

"Regulation 123. Bottling. — Milk or cream of this designa- 
tion shall be delivered to the consumer only in bottles unless 
otherwise specified. 

Regulation 124, Bottles only. — The caps of all bottles contain- 
ing Grade 'A' milk or cream (pasteurized) shall be white with 
the grade and designation 'Grade A (pasteurized),' the name and 
address of the dealer, the date and hours between which pas- 
teurization was completed, and the place where pasteurization 
was performed, clearly, legibly, and conspicuously displayed on 
the outer side thereof. No other word, statement, design, mark, 
or device shall appear on that part of the outer cap containing 
the grade and designation, unless authorized and permitted by 
the Department of Health. A proof print or sketch of such cap, 
sliowing the size and arrangement of the lettering thereon, shall 
be submitted to and approved by the said Department before 
being attachd to the bottles containing milk of the said grade and 
designation. No other words, statement, design or device shall 
appear upon the outer cap unless approved by the Department of 
Health. The size and arrangement of lettering on such cap must 
be approved by the Department of Health. 

"Regulation 125. Pasteurization. — Only such milk or cream 
shall be regarded as pasteurized as has been subjected to a tem- 



844 Definitions and Standards 

peratiire of from 142 to 145 degrees F. for not less than thirty 
minutes. 

"Additional Regulations Governing the Sale of Grade 'B' Milk 
or Cream (Pasteurized). Definition. — Grade 'B' milk or cream 
(pasteurized) is milk or cream produced and handled in accord- 
ance with the minimum requirements of the Regulations herein 
set forth and which has been pasteurized in accordance with the 
Regulations of the Department of Health for pasteurization. 

"Regulation 128. Physical examination of cows. — All cows 
producing milk or cream of this designation must be healthy as 
determined by a physical examination made and approved by a 
duly licensed veterinarian. 

"Regulation 129. Bacterial contents. — No milk under this 
designation shall contain more than 100,000 bacteria per c. c. and 
no cream shall contain more than 500,000 bacteria per c. c. when 
delivered to the consumer, or at 'any time after pasteurization 
and prior to such delivery. No milk supply averaging more than 
1,500,000 bacteria per c. c. shall be pasteurized in this city under 
this designation. No milk supply averaging more than 300,000 
bacteria per c. c. shall be pasteurized outside the City of New 
York to be sold in said city under this designation. 

"Regulation 130. Scoring of dairies. — Dairies producing milk 
or cream of this designation shall score at least 20 points on 
equipment and 35 points on methods, or a total score of 55 points 
on an official score card approved by the Department of Health. 

"Regulation 131. Time of delivery. — Milk of this designation 
shall be delivered Avithin 36 hours. Cream shall be delivered with- 
in seventy-two (72) hours after pasteurization. Cream intended 
for manufacturing purposes may be stored in cold storage and 
held thereat in bulk at a temperature not higher than 32 degrees 
F. for a period conforming with the laws of the state of New 
York. Such cream shall be delivered in containers, other than 
bottles, within twenty-four (24) hours after removal from cold 
storage and shall be used only in the manufacture of products in 
which cooking is required. 

"Regulation 132. Bottling. — Milk of this designation may be 
delivered in cans or bottles. 



Milk and Crkam Regulations 845 

"Regulation 133 — Labeling. — The caps of all bottles contain- 
ing Grade 'B' milk (pasteurized) and the tags attached to all cans 
containing Grade 'B' milk or cream (pasteurized) shall be white 
with the grade and designation 'Grade B (pasteurized),' the name 
and address of the dealer, and the date when and place where 
pasteurization was performed, clearly, legibl}^, and conspicuously 
displayed on the outer side thereof. The caps of all bottles con- 
taining Grade 'B' cream (pasteurized) shall be white with the 
grade and designation 'Grade B Cream (pasteurized),' the name 
and address of the dealer, and the date when and the place where 
bottled, clearly, legibly, and conspicuously displayed on the outer 
side thereof. No other word, statement, design, mark, or device 
shall appear on that part of the outer cap or tag containing the 
grade and designation unless authorized and permitted by the 
Department of Health. A proof print or sketch of such cap or 
tag, showing the size and arrangement of the lettering thereon 
shall be submitted to and approved by the said Department before 
being attached to any receptacle containing milk or cream of the 
said grade and designation. 

"Regulation 134. Pasteurization. — Only such milk or cream 
shall be regarded as pasteurized as has been subjected to a tem- 
perature of from 142 to 145 degrees F. for not less than thirty 
minutes. 

"Additional Regulations Groverning the Sale of Grade 'C 
Milk or Cream (Pasteurized) (for Cooking and Manufacturing- 
Purposes Only). Definition. — Grade 'C milk or cream is milk or 
cream not conforming to the requirements of any of the sub- 
divisions of Grade 'A' or Grade 'B' and which has been pas- 
teurized according to the Regulations of the Board of Health or 
boiled for at l^ast two minutes. 

"Regulation 136. Physical examination of cows. — All cows 
producing milk or cream of this designation must be healthy as 
determined by a physical examination made by a duly licensed 
veterinarian. 

"Regulation 137. Bacterial content. — No milk of this designa- 
tion shall contain more than 300,000 bacteria per c. c. and no 
cream of this grade shall contain more than 1,500,000 bacteria per 
c. c. after pasteurization. 



846 Definitions and Standards 

"Regulation 138. Scoring of dairies. — Dairies producing 
milk or cream of this designation must score at least 40 points on 
an official score card approved by the Department of Health. 

"Regulation 139. Time of delivery. — Milk or cream of this 
designation shall be delivered within 48 hours after pasteuriza- 
tion. 

"Regulation 140. Bottling. — Milk or cream of this desig- 
nation shall be delivered in cans only. 

"Regulation 141. Labeling. — The tags attached to all cans con- 
taining Grade 'C milk (for cooking) shall be white with the 
grade and designation 'Grade C Milk (for cooking),' the name 
and address of the dealer, and the date when and place where 
pasteurization was performed, clearly, legibly, and conspicuously 
displayed thereon. No other word, statement, design, mark, or 
device shall appear on that part of the tag containing the grade 
and designation, unless authorized and permitted by the Depart- 
ment of Health. A proof print or sketch of such tag, showing 
the size and arrangement of the lettering thereon shall be sub- 
mitted to and approved by the said Department before being at- 
tached to the cans containing milk of the said grade and designa- 
tion. The cans shall have properly sealed metal covers painted 
red, 

"Regulation 142. Pasteurization. — Only such milk or cream 
shall be regarded as pasteurized as has been subjected to a tem- 
perature of 145 degrees, for not less than thirty minutes. 

"Additional Regulations Governing- the Sale of Condensed 
Skim-Milk. Definition. — Condensed skimmed milk is condensed 
milk in which the butter- fat is less than twenty-five (25) per 
cent of the total milk solids. 

"Regulation 145. Cans to be painted blue. — The cans contain- 
ing condensed skimmed milk shall be colored a bright blue and 
shall bear the words "Condensed Skimmed Milk" in block letters 
at least two inches high and two inches wide, with a space of at 
least one-half inch between any two letters. The milk shall be 
delivered to the person to whom sold, in can or cans, as required 
in this regulation, excepting when sold in hermetically sealed 
cans. 



Mii^K AND Cream Regulations 847 

"Additional Regulations Governing the Labeling of Milk or 
Cream Brought Into, Delivered, Offered for Sale, and Sold in New 
York City. Regulation 146. Labeling of milk or cream. — Each 
container or receptacle used for bringing milk or cream into or 
delivering it in the City of New York shall bear a tag or label 
stating, if shipped from a creamery or dairy, the location of the 
said creamery or dairy, the date of shipment, the name of the 
dealer, and the grade of the product contained therein, except as 
elsewhere provided for delivery of cream in bottles. 

"Regulation 147. Labeling of milk or cream to be pasteur- 
ized. — All milk or cream brought into the City of New York to 
be pasteurized shall have a tag affixed to each and every can or 
other receptacle indicating the place of shipment, date of ship- 
ment, and the words 'to be pasteurized at (stating location of 
pasteurizing plants).' 

"Regulation 148. Mislabeling of milk or cream. — Milk or cream 
of one grade or designation shall not be held, kept, offered for 
sale, sold, or labeled as milk or cream of a higher grade or desig- 
nation. 

"Regulation 149. Word, statement, design, mark or device 
on label.— No word, statement, design, mark, or device regarding 
the milk or cream shall appear on any cap or tag attached to any 
bottle, can, or other receptacles containing milk or cream Avhich 
words, statement, design, mark, or device is false or misleading 
in any particular. 

"Regulation 150. Tags to be saved. — As soon as the contents 
of such container or receptacle are sold, or before the said con- 
tainer is returned or otherwise disposed of, or leaves the pos- 
session of the dealer, the tag thereon shall be removed and kept 
on file in the store, where such milk or cream has been sold, for a 
period of two months thereafter, for inspection by the Depart- 
ment of Health. 

"Regulation 151. Record of milk or cream delivered. — Every 
wholesale dealer in the city of New York shall keep a record in his 
main office in the said city, which shall show from which place 
or places milk or cream, delivered by him daily to retail stores in 
the city of New York, has been received and to whom delivered, 



848 Definitions and Standards 

and the said record shall be kept for a period of two months, for 
inspection by the Department of Health, and shall be readily ac- 
cessible to the inspectors of the said Department at all times." 



REFERENCES. 

^Circular 136, U. S. Department of Agriculture. 

-Taylor, Geo. B. and Thomas, Harry N. Mimeographed circular, Legal 
Standards for Dairy Products. 

''Report of the committee of Statistics of the milk and cream. Regula- 
tions of the Official Dairy Instructions Ass'n. Jour. Dairy Science Vol. 1 
No. 1, 1917. 



CHAPTER XXII 

MISCELLANEOUS INFORMATION REGARDING 
DAIRY PRODUCTS 

Flow Sheets of Various Dairy Products. — Figs. 176 to 191 indi- 
cate the various steps commonly taken in the handling of all the 
common dairy products, under the American methods of manu- 
facture now in general use. They represent the line or the lines 
of flow of the several products while going through the plant, 
and make it possible readily to visualize the various operations 
involved. 



VACUUM PAN 



dOlNDLNSLD 
WHOLE. MILK 



I 
H0M0GLN12E.R 

COOLLR 

I 
FILLER 

STERILIZER 

—1 



EVAPORATED 
MILK 



WHOLE MILK 



CANL 
SUGAR 



VACUUM PAN 

I 

COOLER 



SWEETENED 
COND. WHOLE 



I GELATIN I 



SEPARATOR 



ICREAMh 
RIPENER 
CHljRN 



|butte.r| IsuttermilkI 
vacuum pan 

I 



CONDENSED 
BUTTERMILK 



VACUUM PAN 

I 
MOMOGENIZER 

I 
COOLER 



[gelatin! 



SKIM 
MILK 



VACUUM PAN 



COND 
SKIM MILK 



CANE 
5UGAR 



VACUUM PAN 

_1_ 



SWEET. CON P. 
SKlM-MlLK 



ICECREAM 
MIX 



PASTEURIZER 

I 

H0M0GEN12ER 

I 

COOLER 

\ 



METHOD 1 



ICECREAM 
MIX 



METHOD Z 



Tig. 176. General Flow Sheet of Milk. 
[849] 



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854 



Miscellaneous Information 




Temperature 



855 



TEMPERATURES FOR HOLDING, MANUFACTURING AND 
STORING DAIRY PRODUCTS. 

Ill the handling of dairy products, there is probably no one 
single factor that influences the quality and the commercial 
value of the product, so much as temperature. Table 173 lists the 
temperatures that in good practice give the best results under the 
various conditions named. 

TABLE 173. 
Temperatures for Holding, Manufacturing and Storing Dairy Products. 



Name of Product. 

Fluid milk and skim-milk to be held under 12 hours after 
milking, not pasteurized 

Fluid milk and skim-milk to be held under 24 hours after 
milking, not pasteurized 

Fluid milk and skim-milk to be held under 48 hours after 
milking, not pasteurized 

Fluid milk or skim-milk, pasteurized, to be held 24 hours or 
less 

Fluid milk or skim-milk, pasteurized, to be held up to 
6 days 

Fluid milk heated to pasteurizing temperatures and held 
without cooling up to 6 hours 

Cream not pasteurized, to be held 24 hours or less 

nuid milk and cream pasteurizing temperatures 

Cream pasteurized, to be held up to 10 days 

Cream pasteurized, to be frozen and held up to 3 montlis . . 

Wliey not pasteurized, to be held 6 hours or less 

Cultured buttermilk, pasteurizing temperature before 
inoculating 

Cultured buttermilk, lactic type, inoculating temperature . 

Cultured buttermilk lactic type, incubating temperature . . 

Cultured buttermilk, Bulgaricus type, inoculating tempera- 
ture 

Cultured biittermilk, Bulgaricus type, incubating tempera- 
ture 

Cultured buttermilk, either tyi)e, liolding temperature.... 

Buttermilk cultures, either lactic or Bulgaricus type. Hold- 
ing temperature 

Ice cream mix to be held for .'24 to 96 hours 

Ice cream hardening and holding 

Evaporated milk hot well temperatures 

Evaporated milk, temperature in vacuum pan 

Evaporated milk before processing. When canned imme- 
diately after condensing 

Evaporated milk before processing. When canned 24 
hours after condensing 

Evaporated milk before processing. When canned 48 liours 
after condensing 



Temp, o F. 


recommended 


50 or below 




40 






34 






40 






34 




142 


to 
40 


145 


140 


to 
34 
25 
50 


145 


170 


to 
68 
68 

98 

98 


190 


45 


to 


50 


In 


water 




35 




32 


to 


40 





to 


5 


160 


to 


212 


125 


to 
60 
42 
40 


140 



856 



Miscellaneous Information 
TABLE 173 (Continued). 



Evaporated milk after processing. When held before pack- 
ing to develop leakers 

Evaporated milk after processing. If consumed within two 
months after manufacture 

Evaporated milk after processing. \\'heii held in storage 
for one year or less 

Sweetened condensed milk, hot well temperatures 

Sweetened condensed milk, pan temperatures 

Sweetened condensed milk. Temperature at which to bar- 
rel or can 

Sweetened condensed milk. When held for early consump- 
tion 

Sweetened condensed milk. When held in storage for one 
year or less 

Bulk imsweetened condensed milk. For consumption inside 
of one week 

Butter churning temperatures, Simimer 

Average about 56° F. Winter 

Where cotton seed meal is fed and under certain feed and 
breed conditions higher churning temperatures may be 
used. 

Butter in cold storage 

Cheese, best temperature for action of rennet in making 
Cheddar cheese 

Clieese, high curing temperature, cheddar cheese 

Cheese, low curing temperature, cheddar cheese 

Cheese in storage 

Temperature at which milk powder can be heated during 
manufacture without impairing flavor 

Milk powder in storage 



68 

Ordinary 

temperature 

35 to 40 
160 to 212 
125 to 140 

About 74 

Ordinary 

temperature 

.35 to 40 

40 
48 to 53 
52 to 60 



-10 



86 


to 


88 


60 


to 


68 


45 


to 
35 

140 


50 


35 


to 


40 



THE ACTION OF MILK UPON METALS AND CERTAIN PROPER- 
TIES OF METALS AND ALLOYS. 

The action of milk upon various metals as well as upon other 
products used in its handling is of importance in several respects. 
The principal factors of interest are the influence of the metals 
upon the flavor of the milk or products derived from it ; life and 
cost of the equipment made from various metals ; properties that 
afi^ect the appearance of the equipment ; the ease or the difficulty 
with which the various metals are kept in a clean, and sanitary 
condition, and heat transmitting qualities of the various metals. 

Relatively little published data is available upon the above 
subjects. Erf made a considerable study of the influence of 
various metals upon the flavor of milk. "A solution of dilute 
lactic acid mixed with citric acid charged slightly with carbon 
dioxide was first used, as it was very difficult to obtain any re- 



Action of Milk on Metals 



857 



action from the small quantities of metal actually dissolved. Then 
we continued to dilute this with milk, and noted the effect upon 
the flavor." 




pifif. 



192. Parts Per MiUion of MetaUic Lactates required to Impart a 
Definite Taste to Water. Based Upon Donauer's Results. 



The order of solubilities of the various metals was as follows : 
wrought iron, east iron, steel, brass, lead, copper and tin. "As 
nearly as we could calculate about one millionth part of copper 
would give a decided flavor to the milk. The amount of flavor 
given by the tin was very small." Careful tests were made in the 
Research Laboratories of Mojonnier Bros. Co.- and the results 
obtained will be given in this chapter. 



858 



Miscellaneous Information 



The best work reported upon the subject is by Donauer of the 
Research Laboratories of the Elyria Enamelled Products Co.^ 

Fig. 192 shows the amount in parts per million in water of 
the various metallic lactates which according to Donauer are 
required to impart a definite taste to water. No exact data is 
yet available to indicate the amount of metallic lactates that are 
required to impart a metallic flavor to milk, or to products de- 
rived from milk. It is well known that many or probably all of 
the metallic salts combine readily with the casein in milk, forming 
insoluble compounds whose properties and reactions are not 
well understood. It is not established if there is any chemical 
reaction between metallic salts and butter fat or other con- 
stituents of the milk besides the casein. The evidence at the 
present time is that a different result should be obtained when the 
metallic lactates are added to milk, as against when added in 
equal amounts to water. On account of the compounds formed by 
metallic salts in milk, probably a larger quantity would be re- 
quired to impart a metallic flavor to milk than to water. 

The solubility of metals in milk is influenced by the tempera- 
tures used; by the time of contact of the metal with the milk, 
and by the acid content of the milk. The results reported by 
Donauer in the case of whole milk are given under Table 174 for 
temperatures at 64 and 149° F. 



TABLE 174. 

Influence of Temperature Upon the Solubility of Metals m Milk Based Upon 
Donauet's Results. Whole Milk Testing .26 Per Cent Lactic Acid. 





Loss in weight in mg. per sq. cm. per 24 hours 


Temperature of 
Experiment 


Alum- 
inum 
Bronze 


Alum- 
inum 


White 
Metal 
Alloy 


Brass 


Bronze 


Copper 


German 
Silver 


Monel 
Metal 


"F. °C. 
64 18 
149 65 


.015 
.250 


.0195 
.57 


.01 
.08 


.095 
.06 


.09 
.055 


.07 
.04 


.05 
.08 


.045 
.07 







Loss in weight in mg. per sq. cm. 


per 24 hours 




Temperature of 
Experiment 


Nickel 


Nickel 
Iron 

Alloy 


Tin 


Iron 


Steel 
Alloy 
No. 1 


Steel 
Alloy 
No. 2 


Zinc 




°F. °C. 
64 18 
149 65 


.095 
.09 


.011 
.15 


.0125 
.15 


.041 
1.71 


.015 
.34 


.014 
.25 


.0575 
2.18 



Action oi^ Milk on Metals 



859 



The results in Table 174 show that in the case of whole milk 
testing .26 per cent lactic acid more of the metals pass into solu- 
tion at pasteurizing temperatures than at room temperature. 
Liedel obtained similar results in the case of copper in fresh whole 
milk testing .18 per cent acid as follows : — 

At 65°F. for 24 hours, .024 mg. dissolved per sq. cm. 

At 140° F. for 7 hours, .071 mg. dissolved per sq. cm. 




Pig-. 193. The Influence of the Acid Content of Milk Upon the SolubUity of 
Metals. Based Upon Donauer's Results. 



At 140° F., Liedel- obtained a solubility of .020 mg. per sq. 
cm., at the end of one hour, and .071 mg. per sq. cm., at the end 
of seven hours in the case of whole milk. The rate of solution 



860 Miscellaneous Information 

is probably much larger during the first hour of contact than 
during succeeding periods. This may be due to the formation of 
a film or coating of milk solids over the metals, or to the presence 
of a more readily soluble coating of an oxide of the metal upon 
its surface before placing the metal in the milk. 

The influence of the acidity of the milk upon the solubility of 
the metals is shown in Fig. 193 which is based upon Donauer's 
results. 

The results obtained show a slight difference in the action, 
being in the majority of cases slightly higher in the case of sour 
milk. 

Relation of Metallic Taste to Quantity of Metal Dissolved.— 

A careful comparison is presented herewith of the relation 
between the amounts of metallic lactates reported by Donauer as 
being required to impart a metallic taste to water, and the 
quantity of metals that were found to pass into solution in fresh 
whole milk. It is assumed that the rate of solution during the 
first hour is equal to 25 per cent of the total amount that passed 
into solution in 24 hours. The method of calculation used by 
Donauer* throughout the comparisons, is given as follows: "Cal- 
culations concerning the pasteurizer were based on an average 
standard 500 gallon vat with rotating coil, the heating surface 
being approximately 20 sq. in. per gallon." 

In the methods in general use the world over for handling 
milk and its products it is seldom that the heat treatment exceeds 
one hour at 140° F. The values given in Table 175 are therefore 
conservative, and in practice the quantities of metal dissolved, 
are probably less than those given, under the conditions named. 
Copper, tin, brass and German silver were found to dissolve in 
smaller quantities than are necessary to impart a metallic flavor. 
Iron and aluminum dissolved in excess of the amount required to 
impart a metallic flavor. 

The above named results are confirmed by practical experience 
covering many years and in various branches of the dairy in- 
dustry. Equipment, used in the manufacture of dairy products, 
made either of pure copper or of tinned copper is known to have 
given many years of daily service without showing appreciable 
wear, other than the mechanical wear caused by daily cleaning. 



Action of Milk on MiiTALS 



861 



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862 Miscellaneous Information 

Hess^ reports one experiment in which milk was pasteurized 
for 30 minutes at 145° F. in a copper vessel, and upon feeding this 
milk to guinea pigs the animals developed scurvy. A portion of 
the same lot of milk pasteurized in a glass vessel and fed to 
guinea pigs did not produce scurvy. Contrary to this result may 
he cited the case of condensed buttermilk which has assumed 
comparatively large commercial proportions. This product is 
manufactured entirely in copper vacuum pans, and its content 
of lactic acid would produce maximum action upon the copper of 
any of the common dairy product, yet it is recognized as being 
able to stimulate growth in poultry and hogs to a remarkable 
degree. No experiments are known to have been made regarding 
its content of antiscorbutic vitamine. 

The life and the relative cost of the various metals, other con- 
siderations being equal, is a deciding factor in the selection of 
the proper metals. Products made of copper have the advantage 
of retaining a considerable part of their original cost in junk 
form. Equipment products in certain sizes or shapes can be pro- 
duced most economically if made in pure copper or in tinned 
copper. Again, in other cases, nearly every advantage is in favor 
of glass enamelled equipment, which has numerous characteristic 
advantages. Aluminum has so far found but scant use in the 
dairy industry, but it has certain properties that may entitle it 
to definite use. It is already being used in France for making 
milk cans and milk bottles. For making containers for milk 
products that are to be handled cold, it may come into further 
use. For handling hot milk products, it meets with the objection 
of its comparative solubility at high temperatures. No exact 
data is available regarding the influence of vacuum upon the 
solubility of metals in milk. Likewise the influences of agitation, 
composition and concentration of the milk products. 

The Action of Condensed and Evaporated Milk Upon Tin and 
Iron. — The action of various foods including condensed and 
evaporated milks upon the solubility of tin and iron in tin cans 
was made the subject of a very comprehensive study under the 
general direction of the research committee of the National Can- 
ners Association.' 

In the case of condensed milk they found "that the amount of 
tin and iron increased slightly during storage, but the increase 



Heat Transmission of Me;tai,s 



863 



had little significance, as the total amounts were very small. The 
tin varied from five to 22 milligrams, and the iron from two to 
10 milligrams per kilograms of product." 

In the case of evaporated milk, ''the average tin content 
varied from 60 to 106 milligrams per kilogram of milk, which 
was considerably higher than with condensed milk. There was 
a slight but definite increase in tin and iron with storage. Differ- 
ences in coating had no effect upon the solution of tin and iron." 

THE HEAT TRANSMISSION OF METALS AND ALLOYS. 

The ease with which heat can be transmitted through various 
metals is a factor of great practical and commercial importance, 
in aiming at the proper choice. This is the factor that influences 
most of all the time element in the handling of dairy products. 
Table 176 gives the conductivity of the more common metals and 
alloys. 

TABLE 176. 
Conductivity for Heat of Certain Metals, Alloys and Glass. 





Temp. ° 


Conductivity 

f for Heat 

Coefficient 

K 


Substance 


Temp. " 


Conductivity 


Substance 


C 


F 


C 


F 


for Heat 1 J 
Coefficient 
K 




18 


64 


.480 


Nickel 


18 


64 


.142 










100 


212 


.492 


Nickel 


100 


212 


.138 








Brass 


17 


63 


.260 


Platinum 


18 


64 


.166 






Brass, yellow 





32 


.204 


Platinum 


100 


212 


.173 







32 


.246 


Silver 


18 


64 


1.006 








Copper 


18 


64 


.918 


Silver 


100 


212 


.992 








100 


212 


.908 


Tin 





32 


.155 













32 


.070 


Tin 


100 


212 


.145 








Gold 


17 


63 


.705 


Zinc 


18 


64 


.265 








Iron, pure 


18 


64 


.161 




100 


212 


.262 






Iron, pure 


100 


212 


.151 


Glass 





32 


.0028 








Iron, steel 


18 


64 


.108 








Iron, steel 


100 


212 


.107 




Lead 


18 


64 


.083 








Lead 


100 


212 


.081 









864 Definitions and Standards 

The coefficient K is the quantity of heat in small calories which 
is transmitted per second through a plate one centimeter thick 
per square centimeter of its surface, when the difference of 
temperature between the two faces of the plate is one degree 
centigrade.^ 

The figures in Table 176 show that next to silver, copper is 
the best conductor of heat known, and it is one of the best 
reasons for the strong position of copper in the dairy industry. 

The knowledge of the relation of milk and its products to 
various metals is incomplete in many particulars, and exact data 
is relatively scarce. Much remains to be learned upon these 
subjects. 

REFERENCES. 

1 Erf, Oscar: Prof, of Dairying Ohio State University, personal letter 
May 4, 1922. 

^ Analytical results all obtained by H. J. Liedel. Research Laboratory 
Mojonnier Bros. Co., Chicago, 111. 

3 Donauer, Max. The action of metals upon Milk. The Ice Cream Review, 
Milwaukee, Wis., p 78, 1922. 
1921, p 115. 

■* Donauer, Max; Letter April 14, 1922. 

= Hess, Alfred F. The antiscorbutic vitamine. Journal Ind. and Eng. Chem. 

« Smithsonian Physical Tables 1921, p 213. 

■^ Relative value of different weights of tin coating on canned food con- 
tainers. National Canners Ass'n. 1917. 

8 Smithsonian Physical Tables. 1921, p 213. 



APPENDIX 

TABLE 177. 
Degiees Twaddell with Corresponding Specific Gravity. 

Temp.6»-lZ- (3) 

60° F. 

Formula: Degrees Twaddell=(200xSp. Gr.)— 200 

Formula: Specific Gravity=^^g^^J^^^^«H:?^ 

200 



Degrees 


Specific 


Degrees 


Specific 


Degrees 


Specific 


Degrees 


Specific 


Degrees 


Specific 


Twaddle 


Gravity 


Twaddle 


Gravity 


Twaddle 


Gravity 


Twaddle 


Gravity 


Twaddle 


Gravity 
60°/60° F 


60° F. 


60°/60° F. 


60° F 


60°/60° F 


60° F 


60°/60° F 


60° F 


60°/G0° F 


60° F 





1.000 


40 


1.200 


80 


1.400 


120 


1.600 


160 


1.800 


1 


1.005 


41 


1.205 


81 


1.405 


121 


1.605 


161 


1.805 


2 


1.010 


42 


1.210 


82 


1.410 


122 


1.610 


162 


1.810 


8 


1.015 


43 


1.215 


83 


1.415 


123 


1.615 


163 


1.815 


4 


1.020 


44 


1.220 


84 


1.420 


124 


1.620 


164 


1,820 


5 


1.025 


45 


1.225 


85 


1.425 


125 


1.625 


165 


1.825 


G 


1.030 


46 


1.230 


86 


1.430 


126 


1.630 


166 


1.830 


7 


1.035 


47 


1.235 


87 


1.435 


127 


1.635 


167 


1.835 


8 


1.040 


48 


1.240 


88 


1.440 


128 


1.640 


168 


1.840 


9 


1.045 


49 


1.245 


89 


1.445 


129 


1.645 


169 


I 845 


10 


1.050 


50 


1.250 


90 


1.450 


130 


1.650 


170 


1.850 


U 


1.055 


51 


1.255 


91 


1.455 


131 


1.655 


171 


1.855 


12 


1.060 


52 


1.260 


92 


1.460 


132 


1.660 


172 


1.860 


13 


1.065 


53 


1.265 


93 


1.465 


133 


1.665 


173 


1.865 


14 


1.070 


54 


1.270 


94 


1.470 


134 


1.670 


174 


1.870 


15 


1.075 


55 


1.275 


95 


1.475 


135 


1.675 


175 


1.875 


16 


1.080 


56 


1.280 


96 


1.480 


136 


1.680 


176 


1.880 


17 


1.085 


57 


1.285 


97 


1.485 


137 


1.685 


177 


1.885 


18 


1.090 


58 


1.290 


98 


1.490 


138 


1.690 


178 


1.890 


19 


1.095 


59 


1.295 


99 


1.495 


139 


1.695 


179 


1.895 


20 


1.100 


60 


1.300 


100 


1.500 


140 


1.700 


180 


1.900 


21 


1.105 


61 


1.305 


101 


1.505 


141 


1.705 






22 


1.110 


62 


1.310 


102 


1.510 


142 


1.710 






23 


1.115 


63 


1.315 


103 


1.515 


143 


1.715 






24 


1.120 


64 


1.320 


104 


1.520 


144 


1.720 






25 


1.125 


65 


1.325 


105 


1.525 


145 


1.725 






26 


1.130 


66 


1.330 


106 


1.530 


146 


1.730 






27 


1.135 


67 


1.335 


107 


1.535 


147 


1.735 






28 


1.140 


68 


1.340 


108 


1.540 


148 


1.740 






29 


1.145 


69 


1.345 


109 


1.545 


149 


1.745 






SO 


1.150 


70 


1.350 


110 


1.550 


150 


1.750 






31 


1.155 


71 


1.355 


HI 


1.555 


151 


1.755 






34 


1.160 


72 


1.360 


112 


1.560 


152 


1.760 






33 


1.165 


73 


1.365 


113 


1.565 


153 


1.765 






34 


1.170 


74 


1.370 


114 


1.570 


154 


1.770 






35 


1.175 


75 


1.375 


115 


1.575 


155 


1.775 






36 


1.180 


76 


1.380 


116 


1.580 


156 


1.780 






87 


1.185 


77 


1.385 


117 


1.585 


157 


1.785 






88 


1.190 


78 


1.390 


118 


1.590 


)58 


1.790 






39 


1.195 


79 


1.395 


119 


1.595 


159 


1.795 







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lO 


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CD 



868 



Appendix 



1 


















t^ 




c 


































i 




M ^ 














































= .S o 










c 






oc 




c 










CO 



















• OS 




00 








oc 














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Oi OS 




|£° 




















a 










CO 












CO CO 






: 1 




1 


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- 00 








3 


06 




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Tt 






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c 







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10 ' 




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C-) 
















ct: 








■* 





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1 




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■ 1 


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'— t c^ 







,* 




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rt '5 g 


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t-- 






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cc 















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00 








oc 


















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<= 















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Ther 
Con- 

ductivit 
K-°C 



















































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0, 




CO 








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^ 






















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00 










CM 



























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itrica! 
on- 
tivity 
0°C 














































































































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C^l 


10 


























SO"-" 


^ 






■0 








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S ■§< 


•^ 






c 













































'"' 




















•— ' 


























Atomic 
Heat 

Sp. Gr. 
XAt.Wt. 
-223°C 





• --^1 


o- 


00 




CO 


c 


•^ 




CO 








oc 


ir 








CO ■ 




eg 


• -^ 


■^ 


"^ 




c 


t 


C*" 




CO 

c^ 









c^ 


c 

cc 


2 


CO 




<M • 












































o U 






































Q 




pecifi 
Heat 

at 
-223°^ 


ce 


: & 


oc 


% 













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C31 







^ 



















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cc 00 




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b- 




If 




0- 




c;i 


c 


„. 




^ 


t^ 






10 oc 


a- 


CO -^ 




in tr* 






CC 


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oc 




•^ 




c 


r^ 


Cf 




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00 10 05 oc 


06 <y 




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^ 






<= 


















c 











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2 


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QC 


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cc 


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c 




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CO 




1 1^ 




a 


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1 


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Cs 


t~- 




oc 


Tt 




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ui CO 1* 


» 




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CO ■ 




C/J 


ti ^ 




























Cs 


--H 00 ^ 


im' b- 




(M ■«** 


















































oc 




































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c 






































CO CD 




c3 o 


c- 


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'* 




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^ 


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<^ 


^ 




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QO 0- 


c^ 


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CN 


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zc 






cs 


C^ 


'' 


C^ 


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CO CC 


co" 




cf (M' 




S *- aj 




■ CO 










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cc 
































c: 


































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5 3 c= 














■<* 


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a 5; 

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C^3 ■<*4 Tt 


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p. 


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p: 


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p. 


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p: 


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p: 


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p: 


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5 




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£ 
1 


■ 

a 

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ll 
II 




^ 





CO ■«*< U" 


J ce 


1^ a 





c 




H Cv 




~ 


if 


cc 


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tr 


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f- 


t-- 


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. t> 


t^ 


t^ 


t^ 




r^ 


t> 




a 


oc 


« 


oc 


00 00 



Appendix 



869 



•^ -*• Tf '^ 



O 05 • GO 



03 .^ 



ai e^ ^ ^ r-i 






A A 



fM 


^H 


f^l 


V 


A 


■H 














a 












U2 


C/J 





o o o o 



Oi Oi O O 
-^*< i— to t^ 



CO '<*' ^ 



Oi lO O O 



lO »o 

— ' o 



o o 



<:C> Oi OS iC to 00 CO 

OO lO »0 O 05 CO 'O 

iM lO »0 <N O '^ ^ 

O O O O O O '— 



txi CO CD 






ec c<i cc b- oo oo 

O OO CD O Oi (M 

(M l-H 1-1 .-H 1-1 



-^ (M OO i-t 

cvti oi '— t (^ 



»0 l-H 



»0 CD 

05 O 



CD O CD 



I Oi 
00 I C^ lO 

ic >o t^ -* 



f- CD ''J* iC 
o6 iC ■<** CO 



'<*<»-<.-( 



CD CD CD CD 

<m" (m' cS ci 



CD CD 



TjHCC'^'^'^-^CO^CS'^OOCC 

(m" c<i (m' ■^' CO 



oo oo oo 



o o o o o 



ic lO (M o l-H .— t o: 



h»l^.— iOC^OC^C^»OCOCOCDCD 



(M (M <M (M ^ 

CO CO CO CO QO 



t-^ C5 "^ 



(M0i00000000-<*<0D'-'OOC00;»0OO 
COCDf— ">—<'— iTt<OOCOiOCOCOt--OOCOOsOi 






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p, . . . . 

o ! ■ '. '. 

a ■ 



w ^ o 



o • — 
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O (73 ^ 



s a a *j 

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O »^ (M 



= o _ _ 
H H H H H 



irSCOt^OOOSO^^IM 



c g g g' e E 
3 o i .2 tS 

3 c rt H i5 g 



OSO^OaC^C^OiOOOOOOOOOO 



Oi o ^ 



?0 t^ oo 05 o 



870 








Appendix 












TABLE 179 
Specific gravity at " corresponding to 


Degrees 


i Baume for liquids lighter 




than water 










idn 


ne° = | 


r 


140 >. 


1 on 


Sp. Gr. at 60° I 


-. - -vr 


id Baui 


Sp. ( 


ir fiO^^ F 1 


130+ Baume° 


60° F. / 


Degrees 


TENTHS OF DEGREES 


Baume 





1 


2 


3 


4 


5 


6 


7 


8 


9 


10 


1.0000 


.9993 


.9986 


.9979 


.9971 


.9964 


.9957 


.9950 


.9943 


.9936 


11 


.9929 


.9922 


.9915 


.9908 


.9901 


.9894 


.9887 


.9880 


.9873 


.9866 


12 


.9859 


.9852 


.9845 


.9838 


.9831 


.9824 


.9818 


.9811 


.9804 


.9797 


13 


.9790 


.9783 


.9776 


.9770 


.9763 


.9756 


.9749 


.9742 


.9736 


.9729 


14 


.9722 


.9715 


.9709 


.9702 


.9695 


.9688 


.9682 


.9675 


.9668 


.9662 


15 


.9655 


.9649 


.9642 


.9635 


.9629 


.9622 


.9615 


.9609 


.9602 


.9596 


16 


.9589 


.9582 


.9576 


.9569 


.9563 


.9556 


.9550 


.9543 


.9537 


.9530 


17 


.9524 


.9517 


.9511 


.9504 


.9497 


.9491 


.9485 


.9479 


.9472 


.9465 


18 


.9459 


.9453 


.9447 


.9440 


.9434 


.9428 


.9421 


.9415 


.9408 


.9402 


19 


.9396 


.9390 


.9383 


.9377 


.9371 


.9365 


.9358 


.9352 


.9346 


.9340 


20 


.9333 


.9327 


.9321 


.9315 


.9309 


.9302 


.9296 


.9290 


.9284 


.9278 


21 


.9272 


.9265 


.9259 


.9253 


.9247 


.9241 


.9235 


.9229 


.9223 


.9216 


22 


.9210 


92.04 


.9198 


.9192 


.9186 


.9180 


.9174 


.9168 


.9162 


.9156 


23 


.9150 


.9144 


.9138 


.9132 


.9126 


.9120 


.9114 


.9109 


.9103 


.9097 


24 


.9091 


.9085 


.9079 


.9073 


.9067 


.9061 


.9056 


.9050 


.9044 


.9038 


25 


.9032 


.9026 


.9021 


.9015 


.9009 


.9003 


.8997 


.8992 


.8986 


.8980 


26 


.8374 


.8968 


.8963 


.8957 


.8951 


.8946 


.8940 


.8934 


.8929 


.8923 


27 


.^917 


.8911 


.8906 


.8900 


.8895 


.8889 


.8883 


.8878 


.8872 


.8866 


28 


.8861 


.8855 


.8850 


.8845 


.8839 


.8833 


.8827 


.8822 


.8816 


.8810 


29 


.8805 


.8799 


.8794 


.8788 


.8782 


.8777 


.8772 


.8766 


.8761 


.8756 


30 


.8750 


.8744 


.8739 


.8734 


.8728 


.8722 


.8717 


.8712 


.8706 


.8701 


31 


.8696 


.8690 


.8685 


.8679 


.8674 


.8669 


.8663 


.8658 


.8653 


.8647 


32 


.8642 


.8637 


.8631 


.8626 


.8621 


.8615 


.8610 


.8605 


.8600 


.8594 


33 


.8589 


.8584 


.8578 


.8573 


.8568 


.8562 


.8557 


.8552 


.8547 


.8542 


34 


.8537 


.8531 


.8526 


.8521 


.8516 


.8511 


.8505 


.8501 


.8496 


.8491 


35 


.8485 


.8480 


.8474 


.8469 


.8464 


.8459 


.8454 


.8449 


.8444 


.8439 


36 


.8434 


.8429 


.8423 


.8418 


.8413 


.8408 


.8403 


.8398 


.8393 


.8388 


37 


.8383 


.8378 


.8373 


.8368 


.8363 


.8358 


.8353 


.8348 


.8343 


.8339 


38 


.8333 


.832^t 


.8323 


.8318 


.8313 


.8309 


.8304 


.8299 


.8294 


.8289 


39 


.8284 


.8279 


.8274 


.8269 


.8264 


.8259 


.8254 


.8250 


.8245 


.8240 


40 


.8235 


.8230 


.8225 


.8220 


.8215 


.8211 


.8206 


.8201 


.8197 


.8192 


41 


.8187 


.8182 


.8177 


.8173 


.8168 


.8163 


.8158 


.8154 


.8149 


.8144 


42 


.8139 


.8134 


.8130 


.8125 


.8121 


.8116 


.8111 


.8107 


.8102 


.8097 


43 


.8092 


.8088 


.8083 


.8078 


.8074 


.8069 


.8064 


.8060 


.8055 


.8051 


44 


.8046 


.8041 


.8037 


.8032 


.8027 


.8022 


.8018 


.8014 


.8008 


.8004 


45 


.8000 


.7995 


.7991 


.7986 


.7981 


.7978 


.7973 


.7968 


.7964 


.7959 


46 


.7955 


.7950 


.7945 


.7940 


.7936 


.7932 


.7928 


.7923 


.7919 


.7914 


47 


.7910 


.7905 


.7901 


.7897 


.7892 


.7887 


.7883 


.7878 


.7874 


.7870 


48 


.7866 


.7861 


.7856 


.7852 


.7848 


.7844 


.7839 


.7835 


.7830 


.7826 


49 


.7821 


.7817 


.7812 


.7808 


.7804 


.7799 


.7795 


.7791 


.7786 


.7782 


50 


.7778 


.7773 


.7769 


.7765 


.7760 


.7756 


.7752 


.7747 


.7743 


.7739 



Appendix 



871 









TABLE 179 


—Continued. 














Specific Gravity 60° F. 


Degrees 




TENTHS OF DEGREES 


Baume 





1 


2 


3 


4 


5 


6 


7 


8 


9 


51 


.7735 


.7730 


.7726 


.7722 


.7718 


.7714 


.7709 


.7705 


.7701 


.7696 


52 


.7692 


.7688 


.7684 


.7680 


.7675 


.7671 


.7667 


.7663 


.7658 


.7654 


53 


.7650 


.7646 


.7642 


.7637 


.7633 


.7629 


.7625 


.7621 


.7617 


.7613 


54 


.7609 


.7605 


.7601 


.7597 


.7593 


.7588 


.7584 


.7580 


.7576 


.7572 


55 


.7568 


.7563 


.7559 


.7555 


.7551 


.7547 


.7543 


.7539 


.7535 


.7531 


56 


.7527 


.7523 


.7519 


.7515 


.7511 


.7507 


.7503 


.7499 


.7495 


.7492 


57 


.7487 


.7483 


.7479 


.7475 


.7471 


.7467 


.7463 


.7459 


.7455 


.7451 


58 


.7447 


.7443 


.7439 


.7435 


.7431 


.7427 


.7423 


.7419 


.7415 


.7411 


59 


.7407 


.7403 


.7399 


.7396 


.7392 


.7388 


.7384 


.7380 


.7376 


.7372 


60 


.7368 


.7364 


.7361 


.7357 


.7353 


.7349 


.7345 


.7341 


.7338 


.7334 


61 


.7330 


.7326 


.7322 


.7318 


.7314 


.7311 


.7307 


.7303 


.7299 


.7295 


62 


.7291 


.7288 


.7284 


.7280 


.7276 


.7273 


.7269 


.7265 


.7261 


.7258 


63 


.7254 


.7250 


.7246 


.7243 


.7239 


.7235 


.7231 


.7228 


.7224 


.7220 


64 


.7216 


.7213 


.7209 


.7205 


.7202 


.7198 


.7194 


.7190 


.7186 


.7182 


65 


.7179 


.7176 


.7172 


.7169 


.7165 


.7161 


.7158 


.7154 


.7150 


.7147 


66 


.7143 


.7139 


.7136 


.7132 


.7128 


.7125 


.7121 


.7117 


.7114 


.7110 


67 


.7106 


.7103 


.7099 


.7095 


.7092 


.7088 


.7084 


.7081 


.7077 


.7074 


68 


.7071 


.7067 


.7064 


.7060 


.7057 


.7053 


.7049 


.7045 


.7042 


.7039 


69 


.7035 


.7032 


.7028 


.7025 


.7021 


.7017 


.7014 


.7010 


.7007 


.7003 


70 


.7000 


.6996 


.6993 


.6989 


.6986 


.6982 


.6979 


.6975 


.6972 


.6969 


71 


.6965 


.6962 


.6958 


.6955 


.6951 


.6948 


.6944 


.6941 


.6937 


.6934 


72 


.6931 


.6927 


.6924 


.6920 


.6917 


.6913 


.6910 


.6906 


.6903 


.6900 


73 


.6896 


.6893 


.6889 


.6886 


.6882 


.6879 


.6876 


.6872 


.6869 


.6866 


74 


.6863 


.6859 


.6856 


.6853 


.6850 


.6846 


.6843 


.6839 


.6836 


.6833 


75 


.6829 


.6826 


.6823 


.6819 


.6816 


.6813 


.6809 


.6806 


.6803 


.6799 


76 


.6796 


.6792 


.6789 


.6786 


.6782 


.6779 


.6776 


.6772 


.6769 


.6766 


77 


.6763 


.6760 


.6757 


.6753 


.6750 


.6746 


.6743 


.6740 


.6737 


.6734 


78 


.6731 


.6727 


.6724 


.6721 


.6717 


.6714 


.6711 


.6708 


.6705 


.6702 


79 


.6698 


.6695 


.6692 


.6689 


.6686 


.6683 


.6679 


.6676 


.6673 


.6670 


80 


.6667 


.6663 


.6660 


.6657 


.6654 


.6651 


.6648 


.6645 


.6641 


.6638 


81 


.6635 


.6632 


.6629 


.6626 


.6623 


.6619 


.6616 


.6613 


.6610 


.6607 


82 


.6604 


.6601 


.6598 


.6595 


.6591 


.6588 


.6585 


.6582 


.6579 


.6576 


83 


.6573 


.6570 


.6567 


.6563 


.6560 


.6557 


.6554 


.6551 


.6548 


.6545 


84 


,6542 


.6538 


.653e 


.6533 


.6530 


6527 


,6524 


.6521 


.6518 


.6515 


85 


.6515 


.650£ 


.650C 


.6503 


,650C 


.6496 


.6493 


.6490 


.6487 


.8484 


86 


.8481 


.6478 


.647^ 


.6472 


.046S 


.6466 


,6463 


,6460 


,6457 


.6454 


87 


.6451 


> .644f 


.644f 


) .6443 


.644C 


.6437 


.643^ 


.6431 


.6428 


.6425 


88 


.6421 


> .64U 


.641( 


) .6413 


.641C 


.6407 


.640^ 


.6401 


,6398 


.6396 


89 


639: 


5 .639f 


) .638/ 


' .638-^ 


.6381 


6378 


.637.'5 


.6372 


.636e 


.6367 


90 


.636^ 


\ 636] 


635J 


i 635^ 


6351 


.634^ 


1 634( 


.6343 


634r 


,6338 



872 Appendix 

TABLE 180. 
Specific Gravity at ^___: corresponding to degrees Baume for liquids 



60° F. 



heavier than water. 



Sp, Gr. 60° F,: 



145 



145 — Deg. Baume 

SPECIFIC GRAVITY (0 



Baume degreesr=145 — | Sp. G r. 60 

60°=1 



/ ^\ 

I Sp. Gr. 60 ^F. 1 

^ 60°=F. J 





TENTHS OF DEGREES 


Degrees 
Baume 





1 


2 


3 


4 


5 


6 


7 


8 


9 





1.0000 


1.0007 


1.0014 


1.0021 


1.0028 


1.0035 


1.0042 


1.0049 


1.0055 


1.0062 


1 


1.0069 


1.0076 


1.0083 


1,0090 


1.0097 


1.0105 


1.0112 


1,0119 


1.0126 


1.0133 


2 


1.0140 


1.0147 


1.0154 


1,0161 


1,0168 


1.0175 


1.0183 


1.0190 


1.0197 


1.0204 


3 


1.0211 


1.0218 


1.0226 


1,0233 


1.0240 


1.0247 


1.0255 


1.0262 


1.0269 


1,0276 


4 


1.0284 


1.0291 


1.0298 


1.0306 


1.0313 


1.0320 


1,0328 


1.0335 


1.0342 


1.0350 


5 


1.0357 


1.0365 


1.0372 


1.0379 


1.0387 


1.0394 


1.0402 


1,0409 


1.0417 


1.0424 


6 


1.0432 


1.0439 


1.0447 


1.0454 


1.0462 


1.0469 


1.0477 


1,0484 


1.0492 


1,0500 


7 


1.0507 


1.0515 


1 . 0522 


1.0530 


1 . 0538 


1.0545 


1.0553 


1.0561 


1.0569 


1.0576 


8 


1.0584 


1.0592 


1.0599 


1.0607 


1.0615 


1.0623 


1.0630 


1.0638 


1.0646 


1.0654 


9 


1.0662 


1.0670 


1.0677 


1.0685 


1.0693 


1.0701 


1.0709 


1.0717 


1.0725 


1.0733 


10 


1.0741 


1.0749 


1.0757 


1.0765 


1.0773 


1.0781 


1.0789 


1.0797 


1.0805 


1.0813 


11 


1.0821 


1.0829 


1.0837 


1.0845 


1.0853 


1.0861 


1.0870 


1.0878 


1.0886 


1.0894 


12 


1.0902 


1.0910 


1.0919 


1.0927 


1.0935 


1,0943 


1.0952 


1,0960 


1,0968 


1.0977 


13 


1.0985 


1.0993 


1 . 1002 


1.1010 


1.1018 


1.1027 


1 . 1035 


1.1043 


1 . 1052 


1 . 1060 


14 


1 . 1069 


1 . 1077 


1 . 1086 


1.1094 


1.1103 


1,1111 


1.1120 


1.1128 


1.1137 


1.1145 


15 


1.1154 


1.1162 


1.1171 


1.1180 


1.1188 


1.1197 


1.1206 


1.1214 


1 . 1223 


1 . 1232 


16 


1 . 1240 


1.1249 


1 . 1258 


1.1267 


1.1275 


1.1284 


1 . 1293 


1.1302 


1.1310 


1.1319 


17 


1 . 1328 


1.1337 


1 . 1346 


1 . 1355 


1.1364 


1 . 1373 


1.1381 


1 . 1390 


1 . 1399 


1 . 1408 


18 


1.1417 


1 . 1426 


1.1435 


1 . 1444 


1 . 1453 


1 . 1462 


1 . 1472 


1.1481 


1 . 1490 


1 . 1499 


19 


1 . 1508 


1.1517 


1 . 1526 


1.1535 


1 . 1545 


1 . 1554 


1.1563 


1 . 1572 


1.1581 


1.1591 


20 


1.1600 


1.1609 


1.1619 


1.1628 


1 , 1637 


1 . 1647 


1.1656 


1 . 1665 


1 . 1675 


1.1684 


21 


1.1694 


1,1703 


1.1712 


1 . 1722 


1,1731 


1.1741 


1 . 1750 


1 . 1760 


1 . 1769 


1,1779 


22 


1.1789 


1.1798 


1 . 1808 


1.1817 


1.1827 


1 , 1837 


1 . 1846 


1 . 1856 


1.1866 


1 . 1876 


23 


1 . 1885 


1.1895 


1.1905 


1.1915 


1 . 1924 


1,1934 


1 . 1944 


1 , 1954 


1 . 1964 


1.1974 


24 


1 . 1983 


1.1993 


1 , 2003 


1.2013 


1 . 2023 


1,2033 


1 . 2043 


1 , 2053 


1.2063 


1.2073 


25 


1.2083 


1.2093 


1.2104 


1.2114 


1,2124 


1,2134 


1.2144 


1.2154 


1.2164 


1.2175 


26 


1.2185 


1.2195 


1.2205 


1.2216 


1.2226 


1,2236 


1 . 2247 


1,2257 


1,2267 


1.2278 


27 


1 . 2288 


1.2299 


1.2309 


1.2319 


1.2330 


1.2340 


1.2351 


1.2361 


1.2372 


1.2383 


28 


1.2393 


1 . 2404 


1.2414 


1.2425 


1.2436 


1.2446 


1.2457 


1.2468 


1.2478 


1.2489 


29 


1 . 2500 


1.2511 


1,2522 


1.2532 


1.2543 


1.2554 


1,2565 


1.2576 


1.2587 


1.2598 


30 


1.2609 


1.2619 


1.2630 


1.2641 


1.2652 


1.2663 


1 . 2674 


1 . 2685 


1.2697 


1.270S 


31 


1.2719 


1.2730 


1.2741 


1.2752 


1,2763 


1.2775 


1.2786 


1.2797 


1.2808 


1.2820 


32 


1.2831 


1 . 2842 


1.2854 


1.2866 


1.2877 


1 . 2888 


1 . 2900 


1.2912 


1.2923 


1.2934 


33 


1.2946 


1.2957 


1.2968 


1.2979 


1.2991 


1 . 3004 


1.3016 


1 . 3028 


1.3040 


1 . 3052 


34 


1 . 3003 


1 . 3075 


1 . 3087 


1.3098 


1.3110 


1.3122 


1.3134 


1.3146 


1.3158 


1.3170 


35 


1.3182 


1.3194 


1.3206 


1.3218 


1 . 3230 


1.3242 


1.3254 


1.3266 


1.3278 


1 . 3290 


36 


1.3302 


1.3314 


1.3326 


1.3339 


1.3352 


1.3364 


1.3376 


1.3389 


1.3401 


1.3414 



Appendix 



873 



TABLE 180— Continued. 
SPECIFIC GRAVITY 60° F. 





TENTHS OF DEGREES 


Degrees 
Baume 





1 


2 


3 


4 


5 


6 


7 


8 


9 


37 


1.3426 


1 . 3438 


1.3451 


1 . 3464 


1.3476 


1.3488 


1 . 3500 


1,3512 


1.3525 


1 . 3528 


38 


1.3551 


1 . 3564 


1.3577 


1.3589 


1.3602 


1.3615 


1.3627 


1.3640 


1.3653 


1.3666 


39 


1.3679 


1.3692 


1 . 3705 


1.3718 


1.3731 


1 . 3744 


1.3757 


1.3770 


1.3783 


1.3796 


40 


1 . 3809 


1 . 3822 


1.3836 


1.3849 


1 . 3862 


1.3875 


1.3888 


1 . 3902 


1.3915 


1 . 3928 


41 


1.3942 


1.3955 


1.3969 


1.3982 


1 . 3996 


1 . 4009 


1.4023 


1.4036 


1.4050 


1.4064 


42 


1.4078 


1.4091 


1.4105 


1.4118 


1.4132 


1.4146 


1.4160 


1.4174 


1.4188 


1.4202 


43 


1.4216 


1.4230 


1.4244 


1.4258 


1.4272 


1.4286 


1.4300 


1.4314 


1.4328 


1.4342 


44 


1.4356 


1.4370 


1.4385 


1.4399 


1.4413 


1.4428 


1.4442 


1.4456 


1.4471 


1.4485 


45 


1 . 4500 


1.4514 


1.4529 


1.4543 


1.4558 


1.4573 


1.4588 


1.4602 


1.4617 


1.4632 


46 


1.4646 


1.4661 


1.4676 


1.4691 


1.4706 


1.4721 


1.4736 


1.4751 


1.4766 


1.4781 


47 


1.4796 


1.4811 


1.4826 


1.4841 


1.4856 


1.4871 


1.4887 


1.4902 


1.4917 


1.4933 


48 


1.4948 


1 . 4963 


1.4979 


1.4994 


1.5010 


1.5026 


1.5041 


1.5057 


1.5073 


1.5088 


49 


1.5104 


1.5120 


1.5136 


1.5142 


1.5167 


1.5182 


1.5199 


1.5215 


1.5231 


1.5247 


50 


1 . 5263 


1 . 5279 


1.5295 


1.5311 


1.5327 


1.5343 


1 . 5360 


1.5376 


1.5392 


1.5409 


51 


1.5425 


1 . 5442 


1 . 5458 


1.5474 


1.5491 


1 . 5508 


1.5525 


1.5541 


1 . 5558 


1.5574 


52 


1.5591 


1.5608 


1.5625 


1.5642 


1.5659 


1.5676 


1.5693 


1.5710 


1 . 5727 


1.5744 


53 


1.5761 


1.5778 


1.5795 


1.5812 


1.5829 


1.5847 


1.5864 


1.5882 


1.5899 


1.5916 


54 


1.5934 


1.5951 


1.5969 


1.5986 


1.6004 


1.6022 


1.6040 


1.6037 


1.6076 


1.6093 


55 


1.6111 


1.6129 


1.6147 


1.6165 


1.6183 


1.6201 


1.6219 


1.6237 


1.6255 


1.6274 


56 


1.6202 


1.6310 


1.6328 


1.6347 


1.6365 


1.6384 


1.6402 


1.6421 


1.6439 


1.6458 


57 


1.6477 


1.6496 


1.6515 


1.6534 


1.6552 


1.6571 


1.6590 


1.6609 


1.6628 


1.6647 


5S 


1 . 6666 


1.6686 


1.6705 


1.6724 


1.6743 


1 . 6763 


1.6782 


1.6802 


1.6821 


1 . 6840 


59 


1 . 6860 


1.6879 


1.6899 


1.6919 


1.6939 


1.6959 


1.6979 


1.6999 


1.7019 


1 . 7039 


■ 60 


1.7059 


1.7079 


1.7099 


1.7119 


1.7139 


1.7159 


1.7180 


1 . 7200 


1.7221 


1.7241 


61 


1.7262 


1.7282 


1.7303 


1 . 7324 


1.7344 


1.7365 


1 . 7386 


1.7407 


1.7428 


1.7449 


62 


1.7470 


1.7491 


1.7512 


1.7533 


1 . 7554 


1.7576 


1.7597 


1.7619 


1.7630 


1.7661 


63 


1.7683 


1 . 7704 


1.7726 


1.7748 


1.7769 


1.7791 


1.7813 


1 . 7835 


1 . 7857 


1.7879 


64 


1.7901 


1.7923 


1.7945 


1.7967 


1 . 7990 


1.8012 


1.8034 


1 . 8057 


1.8080 


1.8102 


65 


1.8125 


1.8148 


1.8170 


1.8193 


1.8216 


1.8239 


1 . 8262 


1.8285 


1.8308 


1.8331 


66 


1 . 8354 


1.8377 


1.8401 


1.8424 


1.8447 


1.8471 


1.8494 


1.8518 


1 . 8542 


1.8566 


67 


1 . 8590 


1.8614 


1 . 8638 


1.8662 


1.8686 


1.8710 


1.8734 


1.8758 


1.8782 


1.8806 


68 


1.8831 


1.8855 


1 . 8880 


1.8905 


1.8929 


1 . 8954 


1.8979 


1.9904 


1.9029 


1.9054 


69 


1.9079 


1.9104 


1.9129 


1.9154 


1.9180 


1.9205 


1.9231 


1.9256 


1.9281 


1.9307 


70 


1.9333 


1 . 9359 


1.9385 


1.9411 


1.9437 


1.9463 


1.9489 


1.9515 


1.9542 


1.9568 



874 



Appendix 



TABLE 181. 
Properties of Saturated Steam/ 



Pressure 




Heat 


Heat of 


Total 








in 


Tempera- 


in 


vaporiza- 


Heat in 


Density or 


Volume 


Total 


pounds 


ture in 


liquid 


tion, or 


heat 


weight 


of 1 


pressure 


per sq. in. 


degrees 


from 


latent 


unit.s 


of cubic ft. 


pound in 


above 


above 


Fahren- 


32° in 


heat in 


from 


in pounds 


cubic 


vacuum 


vacuum 


heit 


units 


heat units 


water at 
32° 




feet 




1 


101.99 


70,0 


1043.0 


1113.1 


0.00299 


334 . 5 


1 


2 


126.27 


94.4 


1026.1 


1120,5 


0.00576 


173.6 


2 


3 


141 ,.62 


109.8 


1015.3 


1125.1 


0.00844 


118.5 


3 


4 


153.09 


121.4 


1007.2 


1128.6 


0.01107 


90.31 


4 


5 


162.34 


130.7 


1000.8 


1131.5 


0,01366 


73.21 


5 


6 


170.14 


138.6 


995.2 


1133.8 


0,01622 


61.67 


6 


7 


176.90 


145.4 


990,5 


1135.9 


0.01874 


53.37 


7 


8 


182.92 


151.5 


986.2 


1137.7 


0.02125 


47.06 


'8 


9 


188.33 


156.9 


982.5 


1139.4 


0,02374 


42.12 


9 


10 


193.25 


161.9 


979.0 


1140.9 


0.02621 


38.15 


10 


14.7 


2 12". 00 


180.9 


965.7 


1146.6 


0.03794 


26.36 


14.7 


15 


213.03 


181.8 


965.1 


1146.9 


0.03826 


26.14 


15 


20 


227,95 


196.9 


954.6 


1151.5 


0.05023 


19.91 


20 


25 


240.04 


209.1 


946.0 


1155.1 


0.06199 


16.13 


25 


30 


250.27 


219.4 


938.9 


1158.3 


0.07360 


13.59 


30 


35 


259.19 


228.4 


932.6 


1161.0 


, 08508 


11.75 


35 


40 


267.13 


236.4 


927.0 


1163.4 


0.09644 


10.37 


40 


45 


274.29 


243.6 


922.0 


1165,6 


0.1077 


9.287 


45 


50 


280.85 


250.2 


917.4 


1167,6 


0.1188 


8.414 


50 


55 


286.89 


256.3 


913.4 


1169.4 


0.1299 


7.696 


55 


60 


292.51 


261.9 


909.3 


1171.2 


0.1409 


7.097 


60 


65 


297.77 


267.2 


905.5 


1172.7 


0.1519 


6.583 


65 


70 


302.71 


272.2 


902.1 


1174.3 


0.1628 


6.143 


70 


75 


307.38 


276.9 


898.8 


1175.7 


0.1736 


5.762 


75 


80 


311.80 


281.4 


895.6 


1177.0 


0.1843 


5.426 


SO 


85 


316.02 


285.8 


892.5 


1178.3 


0.1951 


5.126 


85 


90 


320.04 


290.0 


889.6 


1179.6 


0.2058 


4.859 


90 


95 


323.89 


294.0 


886.7 


1180.7 


0.2165 


4.619 


9.5 


100 


327.58 


297.9 


884.0 


1181.9 


0.2271 


4.403 


100 


105 


331.13 


301.6 


881.3 


1182,9 


0.2378 


4.205 


105 


110 


334.56 


305.2 


878.8 


1184,0 


0.2484 


4.026 


110 


115 


337.86 


308.7 


876.3 


1185,0 


0.2589 


3.862 


115 


120 


341.05 


312.0 


874.0 


1186.0 


0.2695 


3.711 


120 


125 


344.13 


315.2 


871.7 


1186.9 


. 2800 


3.571 


125 


130 


347.12 


318.4 


869.4 


1187.8 


0.2904 


3.444 


130 


140 


352.85 


324.4 


865.1 


1189.5 


0.3113 


3.212 


140 


150 


358.26 


330.0 


861.2 


1191.2 


0.3321 


3,011 


150 


160 


363.40 


335.4 


857.4 


1192.8 


. 3530 


2 , 833 


160 


170 


368.29 


340.5 


853.8 


1194.3 


0.3737 


2,676 


170 


180 


372.97 


345.4 


850.3 


1195,7 


. 3945 


2.535 


180 


190 


377.44 


350.1 


847.0 


1197.1 


0.4153 


2.408 


190 


200 , 


381.73 


354.6 


843,8 


1198.4 


0.4359 


2.294 


200 


225 


391.79 


365.1 


836.3 


1201.4 


0.4876 


2.051 


225 


250 


400.99 


374.7 


829.5 


1204.2 


0.5393 


1.854 


250 


275 


409.50 


383.6 


823.2 


1206.8 


0.5913 


1.691 


275 


300 


417.42 


391.9 


817.4 


1209,3 


0.644 


1.553 


300 


325 


424.82 


399.6 


811.9 


1211.5 


0,096 


1.437 


325 


350 


431.90 


406.9 


806.8 


1213.7 


0,748 


1.337 


350 


375 


438.40 


414.2 


801.5 


1215.7 


0.800 


1.250 


375 


400 


445.15 


421.4 


796.3 


1217.7 


0.853 


1.172 


400 


500 


466.57 


444.3 


779.9 


1224.2 


1.065 


.939 


500 









ApPIvNDIX 






875 






TABLE 181- 


-Continued. 






Temper- 
ature in 
degrees 
Fahren- 
heit 


Total 
pressure 

above 
vacuum 


Heat 

in 
liquid 
from 
32° in 
units 


Heat of 
vaporiza- 
tion, or 
latent 
heat in 
neat units 


Total 

heat in 

heat 

units 

from 

water at 

32° 


Density or 

weight 
of cubic ft. 
in pounds 


Volume Tempern- 

of one ture in 

pound in degrees 

cubic Fahren- 

feet heit 


32 


0.089 


0. 


1091.7 


1091.7 


0.0003 


3387. 


32 


60 


0.254 


28.12 


1072.1 


1100.2 


. 0008 


1244. 


60 


90 


0.692 


58.04 


1051.4 


1109.4 


0.0021 


474 . 6 


90 


120 


1.683 


88.10 


1034.4 


1118.5 


. 0049 


204.4 


120 


140 


2.877 


108.2 


1016.4 


1124.6 


0.0081 


123.2 


140 


150 


3.706 


118.3 


1009.4 


1127.7 


0.0103 


97.03 


150 


IGO 


4.729 


128.4 


1002.3 


1130.7 


0.0130 


77.14 


160 


170 


5.98 


138.5 


995.3 


1133.8 


0.0162 


61.85 


170 


180 


7.50 


148.5 


988.3 


1136.8 


0.0200 


50.01 


180 


190 


9.33 


158.6 


981.3 


1139.9 


0.0245 


40.73 


190 


200 


11.52 


168.7 


974.2 


1142.9 


0.0299 


33.40 


200 


210 


14.12 


178. S 


967.2 


1146.0 


0.0363 


27.57 


210 


220 


17.19 


188.9 


960 . 1 


1149.0 


0.0435 


22.98 


220 


225 


18.91 


193.9 


956.7 


1150.6 


0.0476 


20.99 


225 


230 


20.78 


198.9 


953.2 


1152.1 


0.0521 


19.20 


230 


235 


22.80 


204.0 


949.6 


1153.6 


0.0569 


17.59 


235 


240 


24.98 


209.0 


946.1 


1155.1 


0.0619 


16.14 


240 


245 


27.33 


214.1 


942.6 


1156.7 


0.0674 


14.83 


245 


250 


29.86 


219.1 


939 . 1 


1158.2 


0.0733 


13.65 


250 


255 


32.57 


224.1 


935 . 6 


1159.7 


0.0795 


12.57 


255 


260 


35.48 


229.2 


932.0 


1161.2 


0.0862 


11.60 


260 


265 


38.60 


234.2 


928.6 


1162.8 


0.0933 


10.72 


265 


270 


41.94 


239.3 


925.0 


1164.3 


0.1008 


9.918 


270 


275 


45.51 


244.3 


921.5 


1165.8 


. 1088 


9.187 


275 


280 


49.33 


249.3 


918.0 


1167.3 


0.1173 


8.521 


280 


285 


53.39 


254.4 


914.5 


1168.9 


0.1264 


7.913 


285 


290 


57.72 


259.4 


911.0 


1170.4 


0.1359 


7.356 


290 


295 


62.33 


264.4 


907.4 


1171.9 


0.1461 


6.847 


295 


300 


67.22 


269.5 


903.9 


1173.4 


0.1567 


6.380 


300 


305 


72.42 


274 . 5 


900.5 


1175.0 


0.1680 


5.952 


305 


310 


77.83 


279.6 


896.9 


1176.5 


0.1799 


5.558 


310 


315 


83.77 


284.8 


893.2 


1178.0 


0.1925 


5.195 


315 


320 


89.95 


290.0 


889.5 


1179.5 


. 2058 


4.861 


320 


325 


96.48 


295.2 


885.9 


1181.1 


0.2197 


4.552 


325 


330 


103.38 


300.5 


882.1 


1128.6 


0.2343 


4.267 


330 


335 


110.66 


305.7 


878.4 


1184.1 


0.2498 


4.004 


335 


340 


118.34 


310.9 


874 . 7 


1185.6 


. 2660 


3.760 


340 


345 


126.43 


316.1 


871.1 


1187.2 


. 2830 


3.534 


345 


350 


134.95 


321.4 


867.3 


1188.7 


0.3008 


3.324 


350 


355 


142.91 


326 . 6 


863.6 


1190.2 


0.3195 


3.130 


355 


360 


153.33 


331.8 


859.9 


1191.7 


0.3391 


2.949 


360 


365 


163.22 


337.1 


856.2 


1193.3 


0.3597 


2.780 


365 


370 


173.60 


3,42.3 


852.5 


1194.8 


0.3812 


2.623 


370 


375 


184.49 


347.5 


848.8 


1196.3 


0.4038 


2.476 


375 


380 


195.91 


352.8 


845.0 


1197.8 


0.4276 


2.338 


380 


385 


207.87 


358.0 


841.4 


1199.4 


0.4521 


2.212 


385 


390 


220.39 


363.2 


837.7 


1200.9 


0.4780 


2.092 


390 


395 


233.50 


368.4 


834.0 


1202.4 


0.5051 


1.980 


395 


400 


247.21 


373.7 


830.2 


1203.9 


0.5336 


1.874 


400 


405 


261.55 


378.9 


826.6 


1205.5 


0.5633 


1.775 


405 


410 


276.54 


384.1 


822.9 


1207.0 


0.5945 


1.682 


410 


415 


292.21 


389.4 


819.1 


1208.5 


0.6270 


1.595 


415 


420 


308.57 


394.6 


815.4 


1210.0 


0.6610 


1.512 


420 


425 


325.65 


399.8 


811.8 


1211.6 


0.6970 


1.434 


425 



876 



Appendix 



TABLE 182. 
Tables for conveiting U. S. Weights and Measures Customary to Metiic.= 



;.INEAR. 


CAPACITY. 




Inches 


Feet to 


Yards to 


Miles 
to 




Fluid 
drams to 


Fluid 
ounces 


Liquid 


Gallons to 




millimeters. 


meters. 


meters. 


kilometers. 


I 


or cubic 
centimeters. 


milliliters. 


liters. 




I 


25.4001 


0.304801 


0.914402 


1.60935 


3-70 


29-57 


094633 


3-78533 


2 


508001 


0.609601 


1.828804 


3.21869 


2 


7-39 


^2- '5 


I.S9267 


7.57066 


^ 


76.2002 


0.914402 


2.743205 


4.82804 


3 


11.09 


88.72 


2.83900 


11.35600 


4 


101.6002 


1. 219202 


3-657607 


6.43739 


4 


14-79 


118.29 


378533 


i5-'4'33 


5 


127.0003 


1.524003 


4.572009 


8.04674 


5 


18.48 


147.87 


473167 


18.92666 


6 


152.4003 


1.828804 


5.48641 1 


9.65608 


6 


22,18 


177-44 


5.67800 


22.71199 


7 


177.8004 


2.133604 


6.400813 


11.26543 


7 


25.88 


207.01 


6.62433 


26.49733 


8 


203.2004 


2.438405 


7-315215 


12.87478 


8 


29-57 


'}^A 


7.57066 


30.28266 


9 


228.6005 


2.743205 


8.229616 


14.48412 


9 


3327 


266.16 


8.51700 


34.06799 






SQUA 


RE. 




WEIGHT. 




Square 
inches to 
square cen- 
timeters. 


Square feet 
to square 
decimeters. 


Square 
yards to 
square 
meters. 


Acres to 
hectares. 




Crams to 
milligrams. 


Avoirdu- 
pois ounces 
to grams. 


Avoirdu- 
pois pounds 
to kilo- 
grams. 


Troy 
ounces lo 
grams. 


6.452 


9.290 


0.836 


0.4047 


I 


64.7989 


28.3495 


0.45359 


31.IO34S 


2 


12.903 


18.581 


,.672 


0.8094 


2 


129.5978 


56.6991 


0.90718 


62.20696 


1 


'9-355 


27.871 


2.508 


I.2141 


,"? 


194.3968 


85.0486 


1.36078 


93-3'044 


4 


25.807 


' 37-161 


3-345 


I.6187 


4 


259- '957 


1 13-3981 


1. 81 437 


124.41392 


S 


32.258 


46.452 


4.181 


2.0234 


5 


323-9946 


141.7476 


2.26796 


155-51740 


6 


38.710 


55-742 


5.017 


2.4281 


6 


388.7935 


170.0972 


27215s 


186.62088 


7 


45.161 


65.032 


S-853 


2.8328 


7 


453-5924 


198.4467 


3-17515 


217.72437 
248.82785 


8 


5'-6i3 


74-323 


6.6S9 


>2375 


8 


5'839'3 


226.7962 


3.62874 


9 


58.065 


83-613 


7-525 


3.6422 


9 


583- '903 


25S-'457 


4.08233 


279-93133 


CUBIC. 


I Gunter's chain = 
I sq. statute mile = 


20.1168 
259.000 


meters, 
lectares. 




Cubic 
inches to 
cubic cen- 
timeters. 


Cubic feet 
to cubic 
meters. 


Cubic 
yards to 

cubic 
meters. 


Bushels to 
hectoliters. 












I fathom = 
I nautical mile ^ 


1.829 
'853-25 


meters, 
meters. 


I 


"6.387 


O.02S32 


0.765 


035239 


2 


32774 


0.05663 


1.529 


0.70479 


I foot = 


0.304801 


meter. 


3 

4 

5 


49.161 
65.549 
81.936 


0.08495 
0.11327 
0.14159 


2.294 
3.058 
3823 


1.05718 
1.40957 
1.76196 


I avoir, pound = 
15432-35639 grains = 


453.592427 
1. 000 k 


7 grams, 
ilogram. 


6 


98-323 


0.16990 


4-587 


2.1 1436 








7 


1 14.710 


0.19822 


5-352 


2.46675 








8 


131.097 


0.22654 


6.1 16 


2.81914 








9 


147.484 


0.25485 


6.881 


3-'7iS4 









Appendix 



877 



TABLE 183. 

Tables for converting U. S. weights and measures. Metric to customary.' 



LINEAR. 


CAPACITY. 




Meters to 
inches. 


Meters to 
feet. 


Meters to 
yards. 


Kilometers 
to miles. 




Millili- 
ters or 
cubic cen- 
timeters 
to fluid 
drams. 


Centi- 
liters to 

fluid 
ounces. 


Liters 

to 
quarts. 


Deca- 
liters 
to 
gallons. 


Hecto- 
liters 
to 
bushels. 


I 

3 

4 
5 


39-3700 

78.7400 

1 18. 1 100 

157.4800 
196.8500 


3.28083 
6.56167 
9.84250 

'3- '2333 
16.40417 


1.09361 1 
2.187222 
3280833 

4-374444 
5.468056 


0.62137 
1.24274 
1. 864 11 

2.48548 
3.10685 


r 

3 

4 
5 


0.27 

0.54 
0.81 

i.oS 
1-35 


C 
C 

1 
1 
1 


-338 
.676 
.014 

-353 
.691 


1.0567 
2.II34 
3.1701 
4.2268 
5-2836 


2.6418 
5-2836 

7-9253 
10.5671 
13.2089 


5-6756 
8.513s 
11-3513 
14.1891 


6 

7 
8 

9 


236.2200 
275.5900 
314.9600 
354.3300 


19.68500 
22.96583 ■ 
26.24667 
29.52750 


6.561667 
7.65^278 
8.748889 
9.842500 


3.72822 
4-34959 
4.97096 
5-59233 


6 
7 
8 

9 


1.62 
1.89 
2.16 
2.43 


2.029 
2.367 
2.705 
3-043 


6-3403 

7-3970 
8.4537 
9.5104 


15-8507 
18.4924 
21.1342 
23.7760 


17.0269 
19.8647 
22.7026 
25.5404 










SQUAl 


^E. 




WEIGHT. 


I 

2 

3 

4 
5 


Square 

centimeters 

to square 

inches. 


Square 
meters to 

square 
feel. 


Square 
meters to 

square 
yards. 


Hectares 
to acres. 


I 

3 
4 
5 


Milli- 
grams to 
grains. 


Kilo- 
grams to 

grains. 


Hecto- 
grams to 
ounces 
avoirdupois. 


Kilo- 
grams to 
pounds 
avoirdupois. 


0.1550 
0.3100 
0.4650 
0.6200 

0.7750 


10.764 
21.528 
32.292 

43-055 
53-819 


1.196 
2.392 
3.588 
4.784 
5.980 


2.471 
4-942 
7-413 
9.884 
12355 


0.01543 
0.03086 
0.04630 
0.06173 
0.07716 


15432.36 
30864.7 1 
46297.07 
61729.43 
77161.78 


35274 
7.0548 
10.5822 
14.1096 
17.6370 


2.20462 
4-40924 
6.61387 
8.81849 
1 1. 0231 1 


6 

7 
8 

9 


0.9300 
1.0850 
1.2400 
1-3950 


64-583 
75-347 
86.1 II 
96.875 


7.176 
8.372 
9.568 
10.764 


14.826 
17.297 
19.768 
22.239 


6 

7 
8 

9 


0.09259 
0.10803 
0.12346 
0.13889 


92594.14 
108026.49 
123458.85 
138891.21 


21.1644 
24.6918 
28. 2192 
31.7466 


13-22773 
15-43236 
T 7.63698 
19.84160 






CUBIC. 


WEIGHT. 


I 

3 
4 

5 


Cubic 

centimeters 

to cubic 

inches. 


Cubic 

decimeters 

to cubic 

inches. 


Cubic 

meters to 

cubic 

feet. 


Cubic 

meters to 

cubic 

yards. 




Quintals to 
pounds av. 


Milliers or 

tonnes to pounds 

av. 


Kilograms 

to ounces 

Troy. 


0.0610 
0.1220 
O.183I 
0.2441 
0.3051 


61.023 
122.047 
183.070 
244-094 
305-117 


35-314 
70.269 

105.943 
141.258 
176.572 


1.308 
2.616 
3-924 
5-232 
6.540 


I 

2 
3 

4 
5 


220.46 
440.92 
661.39 
881.85 
1102.31 




2204.6 
4409.2 
6613.9 
8818.5 
1 1023.1 


32.1507 
64.3015 
96.4522 
1 28.6030 
160.7537 


6 

7 
8 

9 


0.3661 
0.4272 
0.4882 
0.5492 


366.140 
427.164 
488.187 

549-210 


211.887 
247.2bl 
282.516 
317-830 


7.848 
9.156 
10.464 
II.77I 


6 

7 
8 

9 


1322.77 
1543-24 
1763.70 
1984.16 




13227.7 
15432-4 
17637.0 
19841.6 


192,9045 
225.0552 
257.2059 
289.3567 



878 



Appendix 



TABLE 184. 
Equivalent of Metric and British Imperial Weights and Measures. Metric to 

Imperial.^ 



LINEAR MEASURE. 



I millimeter (mm.) 

(.001 m.) 
I centimeter (.oi m.^ 
1 decimeter (.1 m) 

I METER (m.) 



I dekameter 

(10 m.) 
I hectometer 

(100 m.) 
I kilometer 

(1,000 m.) 
I myriameter 

( 10,000 m.) 
I micron . . 



= 0-03937 in- 
= 0.39370 " 
= 3-93701 " 

(39-370113 " 
= ] 3.280843 ft. 

( 1.09361425 yds- 
= 10.93614 

= 109.361425 
= 0.62137 mile. 
^ 6.21372 miles. 
= o.ooi mm. 



SQUARE MEASURE. 



I sq. centimeter . . 
I sq. decimeter 

(100 sq. centm.) 
I sq. meter or centi- 

are (100 sq. dcm.) 
I ARE (100 sq. m.) 
I hectare (100 ares 

or 10,000 sq. m.) 



= 0.1550 sq. ni. 

= 15-500 sq. in. 

^ \ 10.7639 sq. ft. 

( 1.1960 sq. yds. 
= 119.60 sq. yds. 

= 2.47 II acres. 



CUBIC MEASURE. 



I cub. centimeter 

(c.c.) (1,000 cubic 

millimeters) 
I cub. decimeter 

(c.d.) (1,000 cubic 

centimeters) 
I CUB. METER ) 

or stere > . . = 
(1,000 c.d.) ) 



= 0.0610 cub. in. 



= 61.024 •' " 

[ 35-3148 cub. ft. 
I 1-307954 cub. yds. 



MEASURE OF CAP.-\CITy. 



I milliliter (ml.) (.001 
liter) 

I centiliter (.01 liter) 

I deciliter (.1 liter) . 
I LITER ( 1,000 cub. 
centimeters or I 
cub. decimeter) 
I dekaliter (loliters) 
I hectoliter (100 " ) 
I kiloliter (1,000 " ) 



= 0.0610 cub. iq. 

__ I 0.61024 " " 

I 0.070 gill. 
= 0.176 pint. 

= 1.759S0 pints. 

= 2.200 gallons. 
= 2.75 bushels. 
= 3-437 quarters. 



APOTHECARIES' MEASURE. 



I cubic centi- ) 
meter (i > 
gram w't) ) 

I cub. millimeter : 



0.03520 fluid ounce. 
0.28157 fiuid drachm. 
1 5-43236 gyai'is weight. 
0.01693 minim. 



AVOIRDUPOIS WEIGHT. 



I milligram (mgr.) . . 
I centigram (.01 gram.) 
I decigram (.1 " ) 

I GRAM 

I dekagram (10 gram.) 
I hectogram (too " ) 



0.01543 gram. 
0.15432 " 
i'54324 grains. 
15-43236 , " 
5.64383 drams, 
3.52739 oz. 
( 2.2046223 lb 

I KILOGRAM (1,000" ) = -j 15432.3564 

( grains. 

=22.04622 lbs. 
= 1. 9684 1 cwt. 



I myriagram (10 kilog.) 
I quintal (100 " ) 
I millier or tonne [ 
(1,000 kilog.) ) ■ ■ 



= 0.9842 ton. 



TROY WEIGHT. 



0.03215 oz. Troy. 
0.64301 pennyweight. 
1 5.43236 grains. 



APOTHECARIES' WEIGHT. 



0.25721 drachm. 
0.77162 scruple. 
15.43236 grains. 



Appendix 



879 



TABLE 185. 

Equivalents of Metric and British Imperial weights and Measures. Metric to 

imperial." 



LINEAR MEASURE. 




MEASURE OF CAPACITY 






Millimeters 

tc 

inches 


Meters 
10 
feet. 


Meters 

to 
yards. 


Kilo- 
meters to 

luiles. ' 

1 




Lita-s 

to 
pints 


Dekaliters 

to 

gallons 


Hectoliters 

to 

busuels. 


Kiloliters 

to 
quarters. 


I 

3 
4 

5 

6 

7 
8 

9 


0.0393701 1 
0.07874023 

O.I 181 1034 

0.15748045 
0.19685056 

0.23622968 
0.27559079 
3 1 496090 

o-3S433'02 


3.28084 
6.56169 
9-84253 
13-12337 
16.40421 

1 9. 68 506 
22.96590 
26.24674 
29.52758 


1.09361 
2.18723 
3.28084 
437446 
5.46S07 

6.56169 
7.65530 
8.74891 

9-84253 


0.62137 ; 

1.24274; 

1. 8641 2 ! 

2.48549 ; 
3.106S6 

372823 
4.34960 
4.97097 
559235 


3 

4 
5 

6 

7 
8 

9 


1.75980 
3.51961 

5-27941 
7.03921 
S.79902 

10.55882 
12.31862- 
14.07S42 
15-83S23 


2.19975 

4-3995' 
6.59926 
8.79902 
10.99877 

13.. 9852 
15.39828 
17.59803 
19.79778 


2.74969 
5-4993'^ 

10.99877 
13.74846 

16.49815 
19.24785 

21-99754 
24-74723 


3-43712 
6.87423 

10.3' 135 
13.74846 
17.. 8558 

20.62269 
24.05981 
27-49692 
30-93404 


SQl 




JARE MEASURE. 


WEIGHT (Avoirdupois). 




Square 

centimeters 

to square 

•.iiches. 


Square 

meters to 

square 

feet. 


Square 
meters to 

square 
yards. 


Hectares 
to acres. 


I 

3 

4 
5 

6 

7 
8 

9 


Milli- 
grams 

to 
grains. 


Kilograms 
to grains. 


Kilo- 
grams 

to 
pounds. 


Quintals 

to 
hundred- 
weights. . 


I 

3 
4 

5 

6 

7 
8 

9 


0.15500 
0.31000 
0.46500 
0.62000 
0.77500 

0.93000 
I.0S500 
1.24000 
1.39501 


10.76393 
21.52786 
32.29179 
43-05572 
53.81965 

64.58357 
7534750 

86 1 1143 
96.87536 


I -19599 
2.39198 
3-58798 
478397 
5.97996 

7-17595 
8.37194 
9.56794 
10.76393 


2.4711 
49421 

7-4132 
9.8842 

12.3553 

14.8263 
17.2974 
19.7685 
22.2395 


0.01543 
0.03086 
0.04630 
0.06173 
0.07716 

0.09259 
0.10803 
0.12346 
0.13889 


■5432-356 
30864.713 
46297.069 
61729.426 
77161.782 

92594.138 
I0S026.495 
123458.S5I 
138891.208 


2.2046? 
4.40924 
66.387 
8.81849 
11. 02311 

13-22773 
15-43236 
17.63698 
1 9.84 1 60 


1.9684. 

3.93683 
5.90524 

787365 
9.84206 

11.8.048 
13.77889 
•5-74730 
17.71572 


CUBIC 


MEASURE. 


Apothe- 
caries' 
Measure. 


Avoirdupois 


Troy Weight. 


Apo-thr- 

CARIKS' 

Wkight. 




Cubic 

decimeters 

to cubic 

inches. 


Cubic 

meters to 

cubic 

feet. 


Cubic 

meters to 

cubic 

yards. 


Cub. cen- 
timeters 
to fluid 

drachms. 




Milliers or 

'tonnes to 

tons. 


Grams 

to minces 

Troy. 


Grams 

to penny, 
weights. 


Grams 

to 

scruples. 


I 

2 

3 
4 

5 

6 

7 
8 

9 


61.02390 
122.04781 
183.07171 
244.09561 
305- "952 

366.14342 
427.16732 
488.19123 

549-2'5>3 


35-3'476 
70.62952 
105.94428 
141.25904 
176.57379 

211.8S855 
247.20331 
282.51807 
317-83283 


•-30795 
2.61591 
392386 
5.23182 

6-53977 

7-84772 
9.15568 
10.46363 
"77159 


0.28157 
0.56314 
0.84471 
..12627 
1.40784 

1 .6894 1 
1.97098 

2-25255 
2.53412 


I 

3 
4 

5 

6 

7 
8 

9 


0.98421 
1 .9684 1 
2.95262 

3-93683 
-4.92103 

590524 
6.88944 

7-S7365 
8.85786 


0.03215 
0.06430 
0.09645 
0. 1 2860 
0.1607s 

0.19290 
0.22506 
0.25721 
0.28936 


0.64301 
1.28603 
..92904- 
2.57206 
3-21507 

3.85809 
4.501.0 
5.14412 

S-787'3 


0.77162 

•-54324 
2.31485 
3.08647 
3.85809 

4.6297. 
5.40.32 
6.17294 
6.94456 



880 



Appendix 



TABLE 186. 

Equivalent of British Imperial and Metric weights and measures. Imperial to 

metric.^" 



LINEAR MEASURE. 



{25.400 milli- 
meters. 
0.30480 meter. 

0-914399 " 
5.0292 meters. 



I inch .... 

I foot (t2 in.) . 
I YARD (3 ft.) . 
I pole (5i yd.) . 
I chain (22 yd. or 

100 links) S 
I furlong (220 yd.) = 201.168 " 

; , ^ J V J 1-6093 kilo- 

1 mile (1,760 yd.) . = I meters. 



SQUARE MEASURE. 



I square mch . . = j 
I sq. ft. (144 sq. in.) = \ 
I SQ. YARD (9 sq. ft.) = ^ 

I perch (30^ sq. yd.) = | 

I rood {40 perches) = 
I ACRE (4840 sq. yd.) = 

I sq. mile (640 acres) = J 259.00 hectares. 



6.4516 sq. cen- 
timeters. 
9.2903 sq. deci- 

meters. 
0.836126 sq. 
meters. 
25.293 sq. me- 
ters. 
lO-i 17 ares. 
0.40468 hectare. 



CUBIC MEASURE. 

I cub. inch= 16.387 cub. centimeters. 
I cub. foot' (1728 ) _ (0028317 cub^me 



cub. in.) 

I ci;b. yard (27 
cub. ft.) 



ter, or 28.317 
( cub. decimeters. 
0.76455 cub. meter. 



APOTHECARIES' MEASURE. 



I gallon (8 pints or J 

160 fluid ounces) ) 
I fluid ounce, f 3 ( S 

(8 drachms) \ ~ ( 

I fluid drachm, f 5 1 i 

(60 minims) ) "^ ( 

I minim, n\ (0.91 146 ( f 

grain weight) \ \ 



4-5459631 liters. 
!8.4i2^ cubic 

centimeters. 
3.5515 cubic 

centimeters. 
0.05919 cubic 

centim.eters. 



Note. — The Apotliecaries' gallon is of the same 
capacity as the Imperial gallon. 



MEASURE OF CAPACITY. 

I gill = 1.42 deciliters. 

1 pint (4 gills) . . , = 0.568 liter. 
I quart (2 pints) . . = 1.136 liters. 
I GALLON (4 quarts) = 4.5459631 " 
I peck ( 2 galls.) . . = 9.092 " 

I bushel (8 galls.) . = 3.637 dekaliters. 
I quarter (8 bushels) = 2.909 hectoliters. 



AVOIRDUPOIS WEIGHT, 



^ ( 64.8 m i 1 1 i - 

} grams. 
= 1.772 grams. 
--= 28.350 '■ 
= 0.45359241 kilogr. 

= 6.350 

= 12.70 " 

_ \ 50-So " 

I 0.50S0 quintal. 

( 1. 0160 tonnes 
S or I016 kilo- 

f "rams. 



1 cirain .... 
! oiificc (16 dr.) . 
I POUNii ( 16 oz. or 

7.000 grains) 
I stiiiie (14 lb.) . 
I quarter (28 lb.) 
I hundredweight ) 

(112 lb.) ( 



I ton (20 cwt.) 



TROY WEIGHT. 

I Troy OUNXF. (480 ) _ 31.1035 grams. 

,i,ranis avoir.) J "^ -^^ * 

1 pennyweight (24 / _^_ „ 

grains) j '^■'^ 

Note. — The Troy gr.iin is of the same weight as 
the Avoirdupois grain. 



APOTHECARIES' WEIGHT. 

I ounce (8 drachms) ^31.1035 grams. 
I drachm,3i (3 scru- J __ -cog « 

pies) j 3- 

I scruple, 9i (20 I - u 

grains) I = ^-296 

Note. — The Apothecaries' ounce is of the same 
weight as the Troy ounce. The Apothecaries' 
grain is also of the same weight as the Avoirdupois 
grain. 



Appendix 



881 



TABLE 186— Continued. 

Equivalent of British Imperial and metric weights and measures. 

Metric." 



Imperial to 



LINE.-VR MEASURE. 


MEASURE OF CAPACITY. 




Inches 

to 

centimeters. 


Feet 

to 

meters. 


Yards 

to 
meters. 


Miles 
to kilo- 
meters. 


i 


Quarts 

to 
liters. 


Gallons 

to 

liters. 


Bushels 

to 

dekaliters. 


Quarters 

10 

hectoliters. 


I 
2 

3 
4 

5 

6 
7 
8 

9 


2-539998 
5.079996 
7.619993 

10. 1 59991 

12.699989 

15.239987 
17-779984 
20.319982 
22.8599S0 


0.30480 
0.60960 
0.91440 
1.21920 
1.52400 

1.82880 
2.13360 

2.43840 
2.74320 


091440 
1.82880 
2.74320 
3.65760 
4.57200 

5.48640 
6.40080 

7-3'5i9 
8.22959 


1.60934 
3.21869 
4.82803 

6.43737 
8.04671 

9.65606 
11.26540 
12.87474 
I4.4840S 


I 
2 

3 

\t 

6 

7 
8 

9 


1. 1 3649 

2.27298 
3-40947 
4-54596 
5-68245 

6.81894 

7-95544 
9.09193 
10.22842 


4-54596 
9-09' 93 

13-63789 
18.18385 

22.729S2 

27-27578 
31.82174 
36.36770 
40.91367 


363677 

7-27354 

10.91031 

14.54708 

18.18385 

21 82062 

25-45739 
29.09416 

3273093 


2.90942 

5.81883 

8-72825 

11.63767 

14.54708 

17.45650 
20.36591 

23-27533 
26.18475 


SQUARE MEASURE. 


WEIGHT (Avoirdupois). 




Square 

inches 

to square 

centimeters. 


Square 

feet 

to square 

decimeters. 


Square 
yarrli 10 
square 
meters. 


Acres to 
hectares. 




Grains 
to milli- 
grams. 


Ounces to 
grams. 


Pounds 
to kilo- 
grams. 


Hundred- 
weights to 
quintals. 


I 

3 
4 

5 

6 

7 
8 

9 


6.45159 
12.90318 

'9-35477 
25.80636 

32-25794 

38-70953 
45.r6ii2 
51.61271 
58.06430 


9.29029 
18.58058 
27.87086 

37-'6ii5 
46.45144 

55-74'73 
65.03201 
74-32230 
83.61259 


0.83613 

1.67225 
2. 508 38 

3-3445° 
4.18063 

5.01676 
5.852S8 
6.68901 
7-525'3 


0.40468 
0.80937 
I.21405 
1. 61874 
2.02342 

2.42811 

2.83279 
3-23748 
3.64216 


I 
2 

3 
4 

5 

6 

7 
8 

9 


64.79892 
129.59784 
'94-39675 
259- '9567 
323-99459 

38S.7935' 

453-59243 

5'8.39'35 
583.19026 


28.34953 

56.69905 

85.04858 

H3.39811 

i4'-74763 

170.09716 
198.44669 
226.79621 
255-'4574 


0.45359 
0.90718 
1.36078 
I.81437 
2.26796 

2.72155 

3-'75'5 
3.62874 
4.0S233 


0.50802 
1.01605 

1.52407 
2.03209 
2.54012 

3.04814 
3-55616 
4.06419 
4.57221 


CUBIC MEASURE. 


Apothe- 
caries' 
Measure. 


Avoirdupois 
(con/.). 


Troy Weight 


Apothe- 
caries' 
Weight 




Cubic 

inches 

to cubic 

centimeters. 


Cubic feet 

to 

cubic 

meters. 


Cubic 

yards 
to cubic 
meters. 


Fluid • 
drachms 
to cubic 

centi- 
meters. 




Tons to 

miUiers or 

tonnes. 


Ounces to 
grains. 


Penny- 
weights to 
grams. 


Scruples 

to 
grams. 


I 
2 

3 
4 
5 

6 

7 
8 

9 


16.38702 
32-77404 
49.16106 
65.54808 
81.935II 

98.32213 
114.70915 
131.09617 
147.48319 


0.02832 
0.05663 
0.08495 

O.I 1327 

O.I4I58 

0.16990 
0.19822 

0.22653 
0.25485 


0.76455 
1.52911 
2.29366 
3.05821 
3.82276 

4.58732 

6.1 1642 
6.88098 


.3- 55 '53 

7.10307 

10.65460 
14.20613 

17-75767 

21.30920 
24.86074 

28.41227 
31.96380 


I 
2 
3- 

4 

5 

I 


I.O1605 
2.03209 
3.04814 
4.06419 
5.08024 

6.09628 

7-"233 
.8.12838 
9.14442 


31.10348 
62.20696 
93-3'044 
124.41392 
i55-5'740 

186.62088 

217-72437 
248.82785 

279-93.' 33 


i-555'7 

4.66552 
6.22070 

7-77587 

9-33104 
10.88622 

12.44139 
13-99657 


1.29598 
2.59196 
3.88794 
5.18391 
6.47989 

7-77587 
9.07185 
10.36783 
11.66381 



882 



Appendix 



TABLE 187. 
Miscellaneous equivalents of Metric weights and measures.' 



LINEAR MEASURES. 

I mil (.001 in.) = 25.4001 fi 

I in. = .000015783 mile 

I hand (4 in.) = 10.16002 cm 

I link (.66 ft.) = 20.11684 cm 

I span (9 in.) = 22.86005 cm 

I fathom (6 ft.) = 1.828804 m 

I rod (25 links) = 5.029210 m 

I chain (4 rods) = 20.11684 m 

I light year (9.5 X 10" km) = 5.9 x lo^^ 

miles 
I par sec (31 X 10'^ km) = 19 X 10" miles 
sV in. = -397 mm jV in. = .794 mm 
A in. = 1.588 mm J in. = 3.175 mm 
I in. = 6.350 mm 5 in. = 12.700 mm 
I Angstrom unit = .0000000001 m 
I micron (fj.) = .000001 m = .00003937 in. 
I millimicron (m/x) = .000000001 m 
I m = 4.970960 links = 1.0936 11 yds. 
= .198838 rod = .0497096 chain 



SQUARE MEASURES. 

I sq. link (62.7264 sq. in.) = 404.6873 cm' 
I sq. rod (625 sq. links) = 25.29295 m' 
I sq. chain (16 sq. rods) = 404.6873 m^ 
I acre (10 sq. chains) = 4046.873 m^ 
I sq. mile (640 acres) = 2.589998 km^ 
I km* = .3861006 sq. mile 
I m* = 24.7104 sq. links = 10.76387 sq 



= -039537 
chain 



ft- 
sq. rod. = .00247104 sq. 



CUBIC MEASURES. 

I board foot (144 cu. in) = 2359.8 cm' 
I cord (128 cu. ft.) = 3.625 m* 

CAPACITY MEASURES. 

I minim (TTl) = .0616102 ml 

I fl. dram (6oTri) = 3.69661 ml 

I fl. oz. (8 fl. dr.) = 1.80469 cu. in. 

= 29.5729 ml 
I gill (4 fl. oz.) = 7.21875 cu. in. = 118.292 

ml 
I liq. pt. (28.875 cu. in.) = .473167 1 
I liq. qt. (57.75 cu. in.) = .946333 1 
I gallon (4 qt., 231 cu. in.) = 3-785332 1 
i dry pt. (33.6003125 cu.in.) = .550599 1 
I dry qt. (67.200625 cu. in.) = 1.101198 1 
ipk. (8 dry qt., 537.605 cu. in.) = 8.80958 1 
I bu. (4 pk., 2150.42 cu. in.) = 35.2383 1 
t firkin (9 gallons) = 34.06799 1 
I liter = .264178 gal. = 1.05671 liq. qt. 
= 33.8147 fl. oz. = 270.518 fl. dr. 
I ml = 16.2311 minims. 
I dkl =■ 18.620 dry pt. = 9.08102 dry qt. 

:^ 1.13513 Pl^- = -28378 bu. 



MASS MEASURES. 
Avoirdupois weights. 
1 grain = .064798918 g 
I dram av. (27.34375 gr.) = 1.771845 g 
I oz. av. (16 dr. av.) = 28.349527 g 
I pd. av. (16 oz. av. or 7000 gr.) 

= 14-583333 oz. ap. (5) or oz. t. 
= 1.2152778 or 7000/5760 pd. ap 
ort. 

= 453-5924277 g 
I kg = 2.204622341 pd. av. 
I g = 15-432356 gr. = -5643833 av. dr. 

= -03527396 av. oz. 
I short hundred weight (100 pds.) 

= 45-359243 kg 
I long hundred weight (112 pds.) 

= 50.802352 kg 
I short ton (2000 pds.) 

= 907.18486 kg 
I long ton (2240 pd.) 

= 1016.04704 kg 
I metric ton = 0.98420640 long ton 
= 1.1023112 short tons 



Troy weights. 
I pennyweight (dwt, 24 gr.) = 1.555174 g: 
gr., oz., pd. are same as apothecary 

Apothecaries' weights. 
I gr. = 64.798918 mg 
I scruple O, 20 gr.) = 1.2959784 g 
I dram (3,3 9) = 3-8879351 g 
loz. (5,8 3) = 31.103481 g 

1 pd (125, 5760 gr.) = 373.24177 g 
I g = 15-432356 gr. =0.7716189 
= 0.2572059 3 = .03215074 5 
I kg = 32.150742 5 = 2.6792285 pd. 

1 metric carat = 200 mg = 3.0864712 gr. 

U. S. I dollar should weigh 12.5 g and the 
smaller silver coins in proportion. 



Appendix 



883 



TABLE 188. 
Conversion of Degrees Centigrade into Degrees Fahrenheit, or vice versa. 



Formula 

Foimula: 



F.=C.x|.+32 



C.=iF.— 32x ^ 
9 



Degrees 


Degrees 


Degrees 


Degrees 


Centrigrade 


Fahrenheit 


Centrigrade 


Fahrenheit 


-17-78 





24 


75-2 


-15 


5-00 


25 


77-0 


-10 


1400 


30 


86-0 


- 5 


23-00 


35 


95 





3200 


37-78 


1000 


1 


33-8 


400 


1040 


2 


35-6 


45 


1130 


3 


37-4 


50 


122-0 


4 


39-2 


55 


131-0 


5 


410 


60 


1400 


6 


42-8 


65 


1490 


7 


44-6 


70 


1580 


8 


46-4 


75 


167-0 


9 


48-2 


80 


1760 


10 


50-0 


85 


185-0 


11 


51-8 


90 


194-0 


12 


53-6 


95 


203 


13 


55-4 


100 


212-0 


14 


57-2 


105 


221-0 


15 


590 


110 


2300 


15-56 


600 


115 


239-0 


16 


60S 


120 


248-0 


17 


62-6 


125 


257-0 


18 


64-4 


130 


266-0 


19 


66-2 


135 


275-0 


20 


68-0 


140 


284-0 


21 


69-8 


145 


293-0 


22 


71-6 


150 


302-0 


23 


73-4 







DIFFERENCE TABLE 



Degrees 


F into C 


C into F 


1 


•56 


1-8 


2 


1-11 


3-6 


3 


1-67 


5-4 


4 


2-22 


7-2 


5 


2-78 


9-0 


6 


3-33 


10-8 


7 


3-89 


12-6 


8 


4-44 


14-4 


9 


5-00 


16-2 


10 


5-56 


180 



884 



Appendix 



TABLE 189. 

Alcohol table for calculating the percentages of alcohol in mixtures of ethyl 

alcohol and water from their specific gravities. (Calculated by U. S. 

Bureau of Standards from its experimental results).^- 



Specific 


Alcohol 1 


Specific 
Gravity 
20° C. 




Alcohol 




Gravity 
20° C. 


Per Cent 


Per Cent 


Grams 


Per Cent 


Per Cent 


Grams 




by Vol. 


by 


Per 




by Vol. 


by 


Per 






4° 


at 20° C. 


Weight 


100 cc. 


4° 


at 20° C. 


Weight 


100 cc. 


0.99823 


0.00 


0.00 


0.00 


0.97704 


10.75 


13.53 


13.22 


99785 


0.25 


0.20 


0.20 


0.97678 


17.00 


13.74 


13.42 


. 99748 


0.50 


0.40 


0.40 


0.97650 


17.25 


13.94 


13.02 


0.99711 


0.75 


0.59 


0.59 


0.97024 


17.50 


14.15 


13.81 


0.99675 


1.00 


0.79 


0.79 


0.97596 


17.75 


14.35 


14.01 


0.99638 


1.25 


0.99 


0.99 


0.97570 


18.00 


14.56 


14.21 


0.99601 


1.50 


1.19 


1.19 


0.97542 


18.25 


14.77 


14.41 


. 99564 


1.75 


1.39 


1.38 


0.97517 


18.50 


14.97 


14.60 


99528 


2.00 


1.59 


1.58 


0.97490 


18.75 


15.18 


14.80 


0.99492 


2.25 


1.79 


1.78 


. 97464 


19.00 


15.39 


15.00 


0.99456 


2.50 


1.98 


1.97 


0.97438 


19.25 


15.59 


15.20 


0.99420 


2.75 


2.18 


2.17 


0.97412 


19.50 


15.80 


15.39 


. 99384 


3.00 


2.38 


2.37 


0.97386 


19.75 


16.01 


15.59 


. 99348 


3.25 


2.58 


2.57 


0.97359 


20.00 


10.21 


15.79 


0.99313 


3.50 


2.78 


2.76 


0.97333 


20.25 


10.42 


15.99 


. 99278 


3.75 


2.98 


2.96 


0.97306 


20.50 


10.03 


16.18 


0.99243 


4.00 


3.18 


3.16 


0.97278 


20.75 


16.84 


16.. 38 


. 99208 


4.25 


3.38 


3.36 


. 97252 


21.00 


17.04 


16.58 


0.99174 


4.50 


3.58 


3.55 


0.97227 


21.25 


17.25 


16.77 


0.99140 


4.75 


3.78 


3.75 


0.97199 


21.50 


17.40 


10.97 


99106 


5.00 


3.98 


3.95 


0.97172 


21.75 


17.07 


17.17 


0.99073 


5.25 


4.18 


4.14 


0.97145 


22.00 


17.88 


17.37 


. 99040 


5.50 


4.38 


4.34 


0.97118 , 


22.25 


18.08 


17.50 


99006 


5,75 


. 4.58 


4.54 


0.97091 


22.50 


18.29 


17.76 


. 98973 


6.00 


4.78 


4.74 


. 97063 


22.75 


18.50 


17.96 


0.98941 


6.25 


4.99 


4.93 


0.97036 


23.00 


18.71 


18.16 


. 98908 


6.50 


5.19 


5.13 


0.97007 


23.25 


18.92 


18.35 


0.98876 


6.75 


5.39 


5.33 


0.97982 


23.50 


19.13 


18.55 


0.98845 


7.00 


5.59 


5.53 


0.90952 


23.75 


19.33 


18.75 


0.98813 


7.25 


5.79 


5.72 


0.96925 


24.00 


19.55 


18.94 


0.98781 


7.50 


5.99 


5.92 


0.96896 


24.25 


19.75 


19.14 


98750 


7.75 


0.19 


6.12 


0.96869 


24.50 


19.96 


19.34 


0.98718 


8.00 


6.40 


6.32 


0.96840 


24.75 


20.17 


19.54 


. 98688 


8.25 


6.60 


6.51 


0.96812 


25.00 


20.38 


19.73 


98658 


8.50 


0.80 


6.71 


0.90783 


25.25 


20.59 


19.93 


0.98627 


8.75 


7.00 


0.91 


0.96755 


25.50 


20.80 


20.13 


0.98596 


9.00 


7.20 


7.10 


0.96727 


25.75 


21.01 


20.33 


. 98566 


9.25 


7.41 


7.30 


0.96099 


26.00 


21.22 


20.52 


. 98537 


9.50 


7.61 


7.50 


. 96669 


26.25 


21.43 


20.72 


0.98506 


9.75 


7.81 


7.70 


0.96641 


20.50 


21.64 


20.92 


0.98476 


10.00 


8.02 


7.89 


0.96612 


20.75 


21.85 


21.12 


98446 


10.25 


8.22 


8.09 


0.90583 


27.00 


22.07 


21.31 


0.98416 


10.50 


8.42 


8.29 


. 96553 


27.25 


22.28 


21.51 


0.98385 


10.75 


8.62 


8.49 


. 96525 


27.50 


22.49 


21.71 


0.98356 


11.00 


8.83 


8.68 


0.96495 


27.75 


22.70 


21.91 


98326 


11.25 


9.03 


8.88 


0.96465 


28.00 


22.91 


22.10 


0.98296 


11.50 


9.23 


9.08 


0.90430 


28,25 


23.12 


22.30 


0.98267 


11.75 


9.44 


9.28 


0.90400 


28,50 


23.33 


22.50 


0.98238 


12.00 


9,64 


9.47 


0.90375 


28.75 


23.55 


22.69 


0.98208 


12.25 


9.84 


9.67 


0.96346 


29.00 


23 . 76 


22.89 


0.98180 


12 . .50 


10.05 


9.87 


0.96310 


29.25 


23.97 


23.09 


0.98150 


12.75 


10.25 


10.07 


0.90285 


29.50 


24.18 


23.29 


0.98122 


13.00 


10.46 


10.26 


. 90255 


29.75 


24.39 


23.48 


. 98094 


13.25 


10.60 


10.40 


0.90224 


30.00 


21.61 


23.68 


0.98066 


13.50 


10.86 


10.66 


0.90193 


30.25 


24.82 


23.88 


. 98037 


13.75 


11.07 


10.85 


0.90103 


30.50 


25.04 


24.08 


. 98009 


14.00 


11.28 


11.05 


0.96132 


30.75 


25.25 


24.27 


0.97980 


14.25 


11.48 


11.25 


0.96100 


31.00 


25.40 


24.47 


, 97953 


14.50 


11.68 


11.44 


. 96069 


31.25 


25.67 


24.67 


0.97924 


14.75 


11.89 


11.64 


0.96030 


31.50 


25.89 


24.80 


0.97897 


15,00 


12.09 


11.84 


. 96005 


31.75 


26.10 


25 . 00 


0.97868 


15.25 


12.30 


12.04 


0.95972 


32.00 


20.32 


25.20 


0.97841 


15.50 


12.50 


12.23 


95939 


32.25 


20.53 


25.40 


0.97813 


15,75 


12.71 


12.43 


0.95900 


32.50 


20.75 


25.04 


0.977S() 


16,00 


12.92 


12.03 


0.95873 


32.75 


26.90 


25.84 


0.97758 


10.25 


13.12 


12.83 


0.95839 


33.00 


27.18 


26.05 


0.97732 


16,50 


13.33 


13.02 


0.95»00 


33.25 


27.39 


26.25 



Appendix 



885 



TABLE 189— Continued. 



Specific 




Alcohol 




Specific 




Alcohol 




Gravity 








Gravity 




















20° C. 


Per Cent 


Per Cent 


Grams 


20° C." 


Per Cent 


Per Cent 


Grains 




by Vol. 


by 


Per 





by Vol, 


by 


Per 




4° 


at 20° C. 


Weight 


100 cc. 


4° 


at 20° C. 


Weight 


100 cc. 


0.95771 


33.50 


27.61 


26.44 


. 92967 


50.25 


42.66 


39.67 


0.95738 


33.75 


27.82 


26.64 


0.92918 


50.50 


42.90 


39.86 


. 95703 


34.00 


28.04 


26.84 


0.92869 


50.75 


43.13 


40.06 


0.95669 


34.25 


28.26 


27.03 


0.92818 


51.00 


43.37 


40.26 


0.95634 


34.50 


28.48 


27.23 


0.92768 


51.25 


43.60 


40.46 


0.95598 


34.75 


28.69 


27.43 


0.92719 


51.50 


43.84 


40.65 


0.95563 


35.00 


28.91 


27.63 


0.92668 


51.75 


44.08 


40.85 


0.95528 


35.25 


29.12 


27.82 


0.92617 


52.00 


44,31 


41.05 


. 95492 


35.50 


29.34 


28.02 


92567 


52.25 


44,55 


41.24 


0.95456 


35.75 


29.56 


28.22 


0.92516 


52.50 


44.79 


41.44 


0.95419 


36.00 


29.78 


28.42 


0.92466 


52.75 


45.03 


41.64 


0.95382 


36.25 


29.99 


28.61 


0.92414 


53.00 


45.27 


41.83 


0.95346 


36.50 


30.22 


28.81 


0,92363 


53.25 


45.51 


42.03 


0.95308 


36.75 


30.43 


29,01 


0,92312 


53.50 


45.75 


42.23 


0.95272 


37.00 


30.66 


29,21 


0,92261 


53.75 


45.98 


42.43 


0.95234 


37.25 


30.87 


29,40 


, 92209 


54.00 


46.23 


42.62 


0.95196 


37.50 


31.09 


29.60 


0,92157 


54.25 


46.46 


42.82 


0.95158 


37.75 


31.31 


29.80 


0,92105 


54.50 


46.71 


43.02 


0.95120 


38.00 


31.53 


29.99 


, 92053 


54.75 


46.94 


43.22 


0.95081 


38.25 


31.75 


30.19 


0,92000 


55.00 


47.19 


43.42 


0.95043 


38.50 


31.97 


30.39 


0,91948 


55.25 


47.43 


43.61 


0.95003 


38.75 


32.19 


30.59 


0,91895 


55 , 50 


47.67 


43.81 


0.94964 


39.00 


32.42 


30.79 


0.91842 


55.75 


47.91 


44.01 


0.94926 


39.25 


32.63 


30.99 


0.91789 


56.00 


48.16 


44.20 


0.94885 


39.50 


32.86 


31.18 


0.91736 


56.25 


48.40 


44.40 


0.94845 


39.75 


33.08 


31,38 


0.91683 


56.50 


48.64 


44.60 


0.94805 


40.00 


33.30 


31,57 


0.91629 


56.75 


48.89 


44.80 


0.94765 


40.25 


33.52 


31.77 


0.91575 


57.00 


49.13 


44.99 


0.94725 


40.50 


33.75 


31.97 


0.91521 


57.25 


49.38 


45.19 


0.94684 


40.75 


33.97 


32.17 


0,91467 


57.50 


49.62 


45.39 


0.94643 


41.00 


34.19 


32.36 


0,91414 


57.75 


49.87 


45.59 


0.94602 


41.25 


34.41 


32.56 


0.91359 


58.00 


50.11 


45.78 


0.94560 


41.50 


34,64 


32.76 


0.91304 


58.25 


50.36 


45.98 


0.94519 


41.75 


34.86 


32.96 


0.91250 


58.50 


50.60 


46.17 


0,94477 


42.00 


35.09 


33.15 


0.91194 


58.75 


50.85 


46.37 


0.94435 


42.25 


35.31 


33.35 


0.91138 


59.00 


51.10 


46.57 


0.94393 


42.50 


35.54 


33.55 


0.91082 


59.25 


51.35 


46.77 


0.94351 


42.75 


35.76 


33.75 


0.91027 


59.50 


51.60 


46.97 


0.94308 


43.00 


35.99 


33.94 


0.90971 


59.75 


51.84 


47.16 


0.94265 


43.25 


36.21 


34.14 


0.90915 


60.00 


52.09 


47.36 


0.94222 


43,50 


36.44 


34.34 


. 90859 


60,25 


52.34 


47.56 


0.94179 


43.75 


36.66 


34.53 


, 90803 


60.50 


52.59 


47.76 


0.94135 


44.00 


36.89 


34.73 


0,90747 


60.75 


52.84 


47.95 


0.94091 


44.25 


37.12 


34,93 


0.90690 


61.00 


53.09 


48.15 


. 94046 


44 . 50 


37.35 


35,13 


, 90633 


61.25 


53.34 


48.35 


0.94002 


44.75 


37 . 57 


35.32 


0,90577 


61.50 


53.60 


48.55 


0.93957 


45.00 


37.80 


35.52 


0.90520 


61.75 


53.85 


48.74 


0.93912 


45.25 


38.03 


35 . 72 


. 90463 


62.00 


54.10 


48.94 


0.93867 


45.50 


38.26 


35.92 


. 90406 


62.25 


54.35 


49.14 


0.93822 


45.75 


38.49 


36.11 


. 90349 


62.50 


54.60 


49.33 


0.93776 


46.00 


38.72 


36.31 


0.90290 


62.75 


54.86 


49.53 


0.93730 


46.25 


38.95 


36.51 


0,90233 


63.00 


55.11 


49.73 


0.93684 


46.50 


39.18 


36.70 


0.90175 


63.25 


55.37 


49.93 


0.93638 


46.75 


39.41 


36.90 


0.90117 


63.50 


55.62 


50.12 


0.93591 


47.00 


39.64 


37.12 


0.90059 


63.75 


55.88 


50.32 


0.93545 


47.25 


39.87 


37.30 


0.90001 


64.00 


56.13 


50.52 


0.93498 


47.50 


40.10 


37.49 


0.89942 


64.25 


56.39 


50.72 


0.93451 


47.75 


40.33 


37.69 


0.89884 


64.50 


56.64 


50.91 


0.93404 


48.00 


40.56 


37.89 


0.89825 


64.75 


56.90 


51.11 


0.93356 


48,25 


40.79 


38.09 


0.89767 


65.00 


57.16 


51.31 


0.93308 


48,50 


41.03 


38.29 


0.89708 


65.25 


57.41 


51.51 


0.93260 


48.75 


41,26 


38.48 


0.89649 


65.50 


57.67 


51.71 


0.93213 


49.00 


41,49 


38.68 


0.89590 


65.75 


57.93 


51.90 


0.93164 


49 . 25 


41.72 


38.87 


0.89531 


66.00 


58.19 


52.10 


0.93116 


49.50 


41.96 


39,07 


0.89471 


66.25 


58.45 


52.30 


0.93066 


49.75 


42.19 


39,27 


0,89411 


66.50 


58.71 


52.49 


0.93017 


50.00 


42,43 


39,47 


0,89351 


66.75 


58.97 


52.69 



886 






Appendix 












TABLE 189- 


-Continued. 








Specific 


Alcohol 1 


Specific 


Alcohol 


Gravity 
20° C. 


Per Cent 


Per Cent 


Grams 


Gravity " 
20° C. 


Per Cent 


Per Cent 


Grams 




bv Vol. 


by 


Per 




by Vol. 


by 


Per 








4° 


at"20° C. 


Weight 


100 cc. 


4° 


at 20° C. 


Weight 


100 cc. 


0.89291 


67.00 


59.23 


52.89 


0.84859 


83.75 


77.90 


66.11 


0.89231 


67.25 


59.49 


53.08 


0.84756 


84.00 


78.20 


66.30 


0.89171 


67.50 


59.75 


53.28 


0.84713 


84.25 


78.50 


66.50 


0.89110 


67.75 


60.02 


53.48 


. 84639 


84.50 


78.80 


66.70 


. 89050 


68.00 


60.28 


53.68 


. 84564 


84.75 


79.11 


66.90 


88989 


68.25 


60.54 


53.87 


0.84489 


85.00 


79.41 


67.09 


. 88928 


68.50 


60.80 


54.07 


0.84413 


85.25 


79.75 


67.29 


. 88867 


■ 68 . 75 


61.07 


54.27 


. 84339 


85.50 


80.02 


67.49 


. 88805 


69.00 


61.33 


54.47 


. 84263 


85.75 


80.33 


67.69 


. 88744 


69.25 


61.60 


54.66 


0.84188 


86.00 


80.63 


67.83 


. 88682 


69.50 


61.86 


54.86 


0.84110 


86.25 


80.94 


68.08 


0.88621 


69.75 


62.13 


55.06 


. 84034 


86.50 


81.25 


68.28 


0.88558 


70.00 


62.39 


55.25 


0.83957 


86.75 


81.56 


68.48 


0.88496 


70.25 


62.66 


55.45 


0.83881 


87.00 


81.87 


68.68 


0.88434 


70.50 


62.92 


55.65 


. 83802 


87.25 


82.18 


68.88 


88372 


70.75 


63.20 


55.85 


0.83725 


87.50 


82.49 


69.07 


88309 


71.00 


63.46 


56.04 


0.83647 


87.75 


82.80 


69.27 


. 88246 


71.25 


63.74 


56.24 


. 83569 


88.00 


83.12 


69.46 


0.88183 


71.50 


64.00 


56.44 


0.83489 


88.25 


83.43 


69.66 


88120 


71.75 


64.27 


56.64 


0.83410 


88.50 


83.75 


69.86 


. 88056 


72.00 


64.54 


56.83 


0.83331 


88.75 


84.06 


70.05 


. 87993 


72.25 


64.82 


57.03 


0.83251 


89.00 


84.39 


70.25 


. 87929 


72 . 50 


65.08 


57.23 


0.83170 


89.25 


84.70 


70.45 


87865 


72.75 


65.36 


57.42 


0.83089 


89.50 


85.03 


70.65 


. 87800 


73.00 


65.63 


57.62 


0.83008 


89.75 


85.34 


70.84 


0.87737 


73.25 


65.91 


57.82 


0.82925 


90.00 


85.67 


71.04 


0.87672 


73.50 


66.18 


58.02 


0.82843 


90.25 


85.99 


71.24 


0.87607 


73.75 


66.45 


58.21 


0.82759 


90.50 


86.32 


71.44 


. 87542 


74.00 


66.72 


58.41 


0.82674 


90.75 


86.64 


71.63 


0.87478 


74.25 


67.00 


58.61 


. 82590 


91.00 


86.97 


71.83 


87413 


74.50 


67.27 


58.81 


0.82505 


91.25 


87.30 


72.03 


. 87347 


74.75 


67.55 


59.01 


0.82419 


91.50 


87.63 


72.23 


. 87282 


75.00 


67.83 


59.20 


. 82332 


91.75 


87.96 


72.42 


0.87217 


75.25 


68.11 


59.40 


0.82246 


92.00 


88.29 


72.62 


0.87151 


75.50 


68.38 


59.60 


0.82159 


92.25 


88.63 


72.82 


. 87084 


75.75 


68.66 


59.79 


0.82071 


92.50 


88.96 


73.02 


0.87019 


76.00 


68.94 


59.99 


0.81982 


92.75 


89.30 


73.21 


. 86952 


76.25 


69.22 


60.19 


0.81893 


93.00 


89.64 


73.41 


. 86885 


76.50 


69.50 


60.39 


0.81803 


93.25 


89.98 


73.61 


0.86818 


76.75 


69.78 


60.58 


0.81711 


93.50 


90.32 


73.80 


0^86751 


77.00 


70.06 


60.78 


0.81620 


93.75 


90.67 


74.00 


. 86684 


77.25 


70.35 


60.98 


0.81526 


94.00 


91.01 


74.20 


0.86617 


77.50 


70.63 


61.18 


0.81432 


94.25 


91.36 


74.40 


0.86548 


77.75 


70.91 


61.37 


0.81337 


94.50 


91.71 


74.59 


. 86480 


78.00 


71.19 


61.57 


0.81241 


94.75 


92.06 


74.79 


0.86412 


78.25 


71.48 


61.77 


0.81144 


95.00 


92.41 


74.99 


'. 86344 


78.50 


71.76 


61.96 


0.81047 


95.25 


92.77 


75.19 


0.86275 


78.75 


72.05 


62.16 


. 80949 


95.50 


93.12 


75.38 


. 86206 


79.00 


72.34 


62.36 


. 80849 


95.75 


93.48 


75.58 


0.86137 


79.25 


72.63 


62.56 


. 80749 


96.00 


93.84 


75.78 


. 86069 


79.50 


72.91 


62.75 


0.80648 


96.25 


94.21 


75.98 


85999 


79.75 


73.20 


62.95 


. 80545 


96.50 


94., 57 


76.17 


. 85928 


80.00 


73.49 


63.15 


0.80442 


96.75 


94.94 


76.37 


. 85859 


80.25 


73.78 


63.34 


. 80337 


97.00 


95.31 


76.57 


85789 


80.50 


74.06 


63.54 


0.80230 


97.25 


95.68 


76.76 


0.85719 


80.75 


74.36 


63.74 


0.80122 


97 . .50 


96.05 


76.96 


0.85648 


81.00 


74.65 


63.94 


0.80012 


97.75 


96.44 


77.16 


. 85578 


81.25 


74.94 


64.13 


0.79900 


98.00 


96.82 


77.36 


. 85507 


81.50 


75.24 


64.33 


. 79786 


98.25 


97.20 


77.55 


. 85436 


81.75 


75.53 


64.53 


0.79672 


98.50 


97.59 


77.75 


. 85364 


82.00 


75.82 


64.73 


0.79553 


98.75 


97.98 


77.95 


. 85293 


82.25 


76.12 


64.92 


. 79432 


99.00 


98.38 


78,14 


'. 85222 


82.50 


76.41 


65.12 


0.79311 


99.25 


98.78 


78.34 


0.85151 


82 . 75 


76.71 


65.32 


0.79188 


99.50 


99.18 


78 . 54 


. 85077 


83 00 


77.01 


65.51 


0.79062 


99.75 


99.59 


78.74 


. 85006 


83.25 


77.30 


65.71 


0.78934 


100.00 


100.00 


78.93 


0.84933 


83.50 


77.60 


65.91 




' 







Appendix 



887 



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888 



Appendix 



TABLE 191. 
Composition of Milk from Different Mammals, 





No. of 
Samples 


Water 


Total 
Solids 


Fat 


Sugar 


Nitrogenous 
Constituents 




Kind of Milk 


Casein 


Albumin 


Ash 


Cow 




87.65 
87.43 
85.71 
80.82 
90.06 
89.23 
90.12 
82.84 
87.13 
86.55 
84.04 
86.13 
62.00 
65.88 
68.14 
90.43 
77.00 
82.10 
69.50 
48.67 
70.18 


12.35 
12.57 
14.29 
19.18 

9.94 
10.77 

9.88 
17.76 
12.87 
13.45 
15.96 
13.87 
38.00 
34.12 
31.86 

9.57 
23.00 
17.90 
30.50 
51.33 
29.82 


3.70 

3.78 

4.78 

6.86 

1.09 

1.92 

1.37 

7.96 

2.87 

3.15 

4.55 

4.80 

23 . 64 

19.73 

20.58 

4.51 

9.26 

3.33 

10.45 

43.76 

19.40 


4.50 
6.21 
4.46 
4.91 
6.65 
5.69 
6.19 
4.86 
5.39 
5.60 
3.13 
5.34 
2.50 
2.61 
7.18 

"s'.ii' 

4.91 
1.95 

none 


2.60 

1.02 

3.20 

4.97 

1.89 

2.63 

.79 

4.16 

3.87 

3.90 

7.23 

3.03 

10.44 

10.35 

3.45 

Not rep 

4.15 

3.12 

15.54 

Not rep 

9.43 


.60 

1.26 

1.09 

1.55 

1.89 

2.63 

1.06 

4.16 

3.87 

3.90 

7.23 

3.03 

10.44 

10.35 

3.45 

orted 

5.57 

5.96 

15.54 

orted 

9.43 


.70 




200 

200 

32 

31 

3 

25 

60 

4 

1 

9 

1 


.30 




76 




.89 




.31 




.53 




.47 




.78 




.74 




.80 




1.05 


Zebra 


.70 




1.42 




2 
2 


1.43 




.65 






Bitch 


46 


.91 


Cat 


.58 


Rabbit .... 




2.56 






.46 


Whale 




.99 









REFERENCES. 

1 Atomic Weight. 

Report of International Committee on Atomic Weights, Journal Ameri- 
can Chemical Society 1921, page 1751. 

Valency Smithsonian Physical Tables 1921, p. 110-111. 

Specific Gravity — Smithsonian Physical Tables 1921, p. 110-111. 

Atomic Heat — Smithsonian Physical Tables 1921, p. 226. 

Specific Heat — Smithsonian Physical Tables 1921, p. 226. 

Atomic Heat — Smithsonian Physical Tables 1921, p. 226. 

Thermal Conductivity — Smithsonian Physical Tables 1921, p. 226. 

Linear Coefficient of Expansion — Smithsonian Physical Tables 1921, p. 
218 and 219. 

Melting Point — Smithsonian Physical Tables 1921, p. 198. 

Boiling Point — Smithsonian Physical Tables 1921, p. 199. 

Van Nostrand's Chemical Annual 1907. 
" Richmond H. Droop. Dairy Chemistry 1899, p. 353. 
8 Courtesy Taylor Instrument Co. Catal. Par. 1500-1600, p. 20. 
* Leland, Walter S. The Steam Engine, Technical World Magazine, Chi- 
cago, 1908, pp. 88 and 89. 

5 Smithsonian Physical Tables 1921, p. G. 
" Smithsonian Physical Tables 1921, p. 6. 
' Smithsonian Physical Tables 1921, p. 7. 
8 Smithsonian Physical Tables 1921, p. 8. 
^ Smithsonian Physical Tables 1921, p. 9. 
'» Smithsonian Physical Tables 1921, p. 10. 
"Smithsonian Physical Tables 1921, p. 11. 

1- Official and Tenatinve Methods of analysis of the Ass'n of Official Agr. 

Chemist. 
13 Courtesy the Pfaudler Co., Rochester, New York. 



Index of Proper Names 



Adams, 14 

American Public Health Assn., 552 

Anderson, J. F.. 521 

Arrhenius, S-, 665 

Association of Official Agricultural 

Chemists, 568, 570, 572. 576, 579. 

614, 619, 620, 632. 641, 648, 884, 

886 
Atkins, 656 
Atwater. W. O.. 432 
Ayers, S. H.. 521. 608 

B 

Babcock & Wilson Co.. 704 

Baer, A. C. 443. 799 

Railcy, 5, 2i2 

Baker, H. A.. 769 

Baker, J. C, 523, 660, 667, 678 

Balton, E. R., 39 

Barber, 525 

Barnett. G. D., 502 

Barthel. C, 32, 38, 656 

Bartoli, 445 

Beau, 32, 595 

Bellis, B.. 593 

Berrv, J. L., 498 

Bicsterfeld, 43 

Biprelow, W. D., 40, 58, 59, 590, 666 

BoRue, R. H„ 283 

Bordas. 592 

Bosworth, A. W., 16 

Bothell, F. H. 289 

Breed, R. S., 498, 500, 507, 515, 519 

523 
Brew, J. D., 498, 515. 519 
Browne, C. A., 19. ii 
Bryant. A. P., 432 
Buchanan, 524 
Bundy, F. M., 49 
Bunsen, 770 
Burr, 2,2 
Butterman, S-, 573 



California and. Southwestern States 
Tee Cream Manufactures Assn., 
800 

Cathcart, P. H., 666 



Cavanaugh. 7i7 

Chapman, H. S., 502 

Chesney, 525 

Clark, A. W., 646 

Clark, M. W., 498, 676. 682 

Commission on Milk Standards. 519 

Comittee on, 

Food and Drug Definitions and 

Standards, 810 
Leeral Standards and Score 

Cards, 800 
Standard ^^lethods for the Bac- 
teriological Examination of 
Milk, 498 
Standard Methods of Bacterio- 
logical Analysis, 498 
Statistics of Milk and Cream. 828 
Technique of the Society of 
American Bacteriologists, 521 
Congden, L. A., 633 
Conn, H. W., 551 
Cook, A. A., 634 
Coolidge, L. H., 764 
Cromley, R. H., 286 
Cross, J. A., 145, 146, 172, 176, 416 
Cusick, J. T.. 30 
Cutler, T. H., 446 



Dalbarg, A. O., 574, 607 
Dcarstyne, R. S.. 506 
Donauer. M., 858 
Dottercr. W. D., 498, 507 
DuBois. L., 646 
Duhrunfaut. 23. 294 
Duckwall, E. W.. 495 



E 

Eckels, C. H., 559, 764 
Erf, O., 150, 856 
Evenson, O. L- 43, 609 



Fitzgerald, 40. 58, 59 

Fleischman, 56 

Frandsin, J. H., 800 

Frohring. W. O., 55, 450, 451, 525, 

528, 529, 550 
Frost, W. D., 520 



[891] 



892 



IndKx of Proper Names 



Garner, H. S., 607 
Gill, A, H., 704 
Gordon, P., 38 
Gottlieb, E., 36 
Govers, 40 
Grimmer, 656 
Grinrod, 40 
Groth, P., 289 

H 

Hall, F. H.. 549 

Hall, T., 299, 461 

Hamilton, Dr., 715 

Hammer, B. S.. 275, 294, 445, 650 

Hanna, E. C, 455 

Harrison, 588 

Hart, E. B., 549, 569, 726. 7iZ, 735 

Hastings, E. G., 522 

Heineman, P., 656 

Heller, 287 

Hess. A F., 862 

Hill, H. W., 507 

Hoffman, C-, 522 

Hubl, 630 

Hudson, C. S., 23 

Hunziker, O. E., 551, 616 



International Committee on Atomic 
Weights, 866-869 



Tackson, D, D., 522 
Johnson, A. R., 275. 445, 650 
Johnson, W. T.. 608 



K 

Kirchner, W., 21 

Klein, L. M., 60, 61, 287 

Kropat, K.. 39 



Lang, 2)7 

Latzer, R. L., 72,7 

I.each, 39 

Eeland, W. S., 708. 874, 875 

Liedel, H. J., 23, 172. 294. 578, 857 

Lubs, H. A., 498, 682 

M 

Mack, E., 23, 294 
Marshall, 15 
McCrudden. F. H.. 683 
McCullum, 1-:. v., 30 
McElroy, 590 



McGill, A., 442 

Mclnerney, T. J., ZZ, 52, 563, 727 

Medalia, L. S., 503 

Melick, C. W., 486 

Meniere, G. J., 39 

Mojonnicr, J. J., 44, 58, 59, 77. 302, 

432 
Mojonnier, T.. 2?,, 40, 289, 302, 432. 

664, 717, 730, 756 
Morse, J. B., 455 
Mortensen, M., 443, 800 



Palmer, L. S.. 764 
Patrick, Dr., 39 
Pearson, R. A., 142 
Penfold, 525 
Peterson, R. W.. 302 
Pfaudler Co., 887 
Poole, 704 
Popp, M.. 2>7 
Prucha, M. J., 521 

R 

Rackowski, 592 

Rice. F. E., 32, 726 

Richmond, H. D., 39, 56, 275, 656, 

883 
Robinson, R, H., 611 
Rogers, T,. A., 735 
Rohrig, 37 
Rose, B., 36 
Rothenfusser, 591 
Ruehle, G. L. A.. 521 
Russell, H. J., 32 



Schreib. H., 36 

Schroeder, M. C, 521 

Sebelien, 29 

Shaw, 559 

Sherman, J. M.. 498, 522 

Skinner, W. W., 283 

Slack. F. H., 498 

Smithsonian Physical Tables, 866- 

869, 876-882 
Snow, 708 
Soillard. E., 23 
Soldner, 29 

Sommer, H. H., 726, 732, 735 
Sorensen, 502 

Stocking, 498. 510, 549, 656 
Stracciati, 445 
Supplee, G. C, 30, 593 



Taylor, G. B., 822 

Taylor Instrument Co., 865 



Indkx of Prope;r Namcs 



893 



Telling- Belle Vernon Co.. 55, 550 

Thomas, H. N., 822 

Thomsen, 38 

Titus, 60, 61 

Tonney, F. O., 521 

Tracy, D. H., 302 

Traube, 33 

Travis, R. P., 296 

Troy, H. C, 13, 53, 77, 615, 622 



Van Nostrand. 866 
Van Slyke. L. L.. 16, 21. 32, 549 
576, 660, 667, 678 



W 

Walker, W. O., 569 
Washburn, R. AI., 443. 457, 800 
Weibull, 37 
Wells, H. L., 76 
Werner, P., 515 
Whitaker, G M., 772 
White, W. B.. 13. 14. 583 
Wilcox, E. v.. 488. 613 
Williams. O. E., 289 
Winton, A., 439, 628 
Woodman, A. G., 634 



Zollcr, H. F., 289 



Index of Subjects 



Acid, 
acetic, 6 

apparent, in milk, 32 
butyric, in fat, 19 
caproic, in fat, 19 
caprylic, in fat, 19 
carbonic, 30 

citric, in milk, IS, 32, 31 
hydrochloric, 6, 7, 30 
lactic, in milk, 26-28 
lauric, in fat, 19 
myristic, in fat, 19 
nitric, 6 
oleic, in fat, 19 
oxalic, 6 

palmitic, in fat, 19 
phosphoric, 30, 2>2 
rosolic, 6 
stearic, in fat, 19 
sulphuric, 6, 30 
tests, 601 

Acidity, 

of evaporated milk, 765 
of various dairy products, 604 
Agar, 

composition of beef extract, 5 

501 
preparation of. 503-506 

Albumin, 15, 28, 29, 575. 663 
composition of, 29 
determination of. in milk. 575 
preparation of pure. 663 
uses of. 29 

Alcohol, 6, 27, 44-48 
amy], 6 
ethyl, 6 

functions of, in Mojonnier test, 
purity of. 44 

quality of, for Mojonnier test, 
specific p^ravitv of, 44 
table. 884-886" 
test, for milk. 606 

Ammonia, 6 
Analysis, 

of butter, 614-620 

of casein, to determine qual 
573-575 



of cheese, 620-624 

of dairy products for thickeners. 

633-638 
of dairy products for lime, 576-578 
of dairy products, 554-683 
of dairy products for sugar, 579- 

596 
of fat for foreign fats, 626-632 
of gelatin, 645 to 647 
of gmn arabic, 647, 648 
of gum tragacanth, 648 
of milk for albumin, 575 
of milk for ash, 576 
of milk for acid. 601-604 
of milk for casein, 568-570 
of milk for citric acid, 593-596 
of milk for lecithin, 592 
of milk for nitrogen, 570-572 
of milk for preservatives. 609 
of milk for skimming and water- 
ing. 564 
of milk chocolate, 572, 573, 632 
of salt, 638-641 
of vanilla extract, 641-643 
of vanilla resins, 644-645 

Apparatus, 

for laboratorj', 4 
00. for making l)acteriological tests, 

plate method. 498 
for making bacteriological tests. 

Breed method. 515 
for propagating pure cultures, 531 

Argonin, 22 
Asbestos, fibre, 7 

Ash, 

composition of, 29 
in milk. 29, 576 

separation of, from skim-milk, 664 
45 



44 



B 



Babcock test, 14. 36. 41 

composition of fat in. 56 
Bacteria, city standards for, in milk 
and cream. 831. 832 
commercial application of. 523 
detection of specific, in milk. 522 
ity. in dairy products, 80 

in milk, 485 
[895] 



896 



Index of Subjects 



in ice cream mix, when prepared 
by Mojonnier vacuum pan 
method, 303 

state standards on, content in 
milk and cream, 822 

strain of, recommended for com- 
mercial uses, 523 

types of, found in milk, 485-498 
Bacteriological counts, 

apparatus for making, plate 
method, 498 

apparatus for making. Breed 
method, 515 

collection of samples, for, 498-500 

composition of media for making, 
500 

incubation temperatures for, 514 

macroscopic colony, Petri plate 
method, 500-515 " 

microscopic, Breed method, 515- 
521 

preparation of media for making, 
503-506 

reports of, plate method, 509 

sources of error, in making, plate 
method, 508 

verification and research meth- 
ods, 521 

Balance, 

analytical, IZ 

care and use of, 72-77 

chainoniatic, 67, 74-77 

oscillations of, 76 

specific gravity chainomatic, 554, 
556, 557 

weights for, 74 

Westphal, 59 
Boiling point, 

relation of vacua and rate of 
evaporation to, 685 
Bottle, 

composite samples, 80 

specific gravity, 555 
Breed method for making bacterio- 
logical counts, 515-521 
Brine, 

temperature of, for freezing ice 
cream, 457 

pressure of, for freezing ice 
cream, 457 
Burettes, 

automatic for Alojonnier test, 66 
Butter, 

analysis of, 614-620 

determination of moisture in, 614 

determination of salt in, 615-619 



determination of fattj- acids in, 

619 
fat test for, 110 

flow sheet of, manufacture, 850 
sampling, 88 
score card for, 790-792 
solids test for, 128 
specific heat of, 654, 655, 656 
temperature to churn and hold, 

856 
use of culture, in making, 550 
Butterboat, 

illustration of, 97 
directions for weighing with, 97 
Butterfat, see fat 
Buttermilk, 

condensing in the vacuum pan, 

718 
definition of, 811 
fat test for, 106 
sampling, 89 
score card for, 793 
total solids test for, 124 
Buttermilk, condensed 
fat test for, 107 

relation specific gravity, temper- 
ature and composition in, 438 
Buttermilk (culture), 

apparatus for propagating cul- 
ture, for, 532 
application of pure cultures in the 

manufacture of, 543 
directions for making, 544-546 
flow sheet of, manufacture, 854 
preventing wheying-off in, 547 
quantity of culture to use in 

making, 543 
temperature to hold, 855 
temperature to inoculate skim- 
milk in making, 855 
temperature to incubate in mak- 
ing, 855 
Butyrin, 15, 19 



Calcium citrate, in evaporated milk. 

761-764 
Calories, in ice cream, 275, 278 
Cane sugar, see sucrose 
Capacity, 

of vacuum pans, 689, 690 

of cylindrical tanks, 887 
Caprinin, 15. 19 
Caproin, 15, 19 
Caprylin, IS. 19 



Indkx of Subjects 



897 



Caramel, composition of, for use in 
ice cream, 287 

Cards, score, see score cards 

Casein, 

as a food, 22 
composition of, 21 
condition of, in milk, 21 
determination of, in milk, 568-570 
determination of, in milk choco- 
late, 572 
determining quality of, 573-575 
t1ow sheet of, manufacture, 854 
precipitation of, 21, 22 
preparation of, pure, 660-663 
separation of, 21 
uses of, 22 

Certified milk, score card for, 784- 
786 

Cheese, analysis of, 620-624 
ash in, 622 
dclinition of and standards for, 

813-815 
determination of acidity in, 622 
determination of salt in, 624 
distribution, of water in, 89 
fat test for, 110, 621 
flow sheet of, manufacture, 853 
moisture in, 89. 621. 622-624 
sampling', 89 
score card for, 794-798 
solids test for, 127 
temperature to cure and hold, 856 
use of culture in making, 548-550 

Chemical constants of the elements, 

866-869 
Chemical properties, 

of ice cream mixes. 272-300 
of milk. 12-33 
Chocolate, composition of, 438, 439 
Citric acid, 
crystals, 32 
determination of. in milk, 593, 31. 

?>2 
determination of. in milk powder. 

594 
determination of, in sweetened 

condensed milk. 594 
separation of, 664 

City standards, 828-848 
Coal, consumption, relation to 
steam production, 703, 704 

Cocoa, 

composition of, 439, 440 
fat test for, 110 
nibs. 440, 439 
sampling, 92 



shells, 439, 440 
solids test for, 110 
Cocoa syrup, composition for use 

in ice cream, 287 
Coagulation, point of, in evapor- 
ated. 72S-72,7, 752-754 

Composite samples, 

bottles for, 80 

care of, 84 

of cream, 85 

definition of, 83 

for standardizing evaporated milk. 

164 
for standardizing sweetened con- 
densed milk, 222 
for standardizing various milk 

products, 131 
frequency of testing, 84 
instruments for taking. 81-83 
preparing for testing, 85 
preservatives for, 84 
water heater for, 85 
Composite test liquid, 84 
Composition, 

of cocoa, cocoa nibs and cocoa 

shells, 440 
of fruits and flavors for ice cream, 

287, 288 
of ice cream mixes, 272-432 
of ice cream mix as affecting the 

overrun, 447 
of milk, 12, 13-33 
of milk from different mammals, 

888 
of milk chocolate, 440 
of miscellaneous milk foods, 441 
of products used in ice cream 

mixes, 313 
relation to defects in ice cream, 

289-300 
suggested, of ice cream mixes, 

273 

Condenser, on vacuum pan, 688 
Condensed buttermilk, 
relation specific gravity, temper- 
ature and composition in, 438 
fat test for, 107 
Condensed milk, see unsweetened 
condensed milk, 

Constants, 

evaporated milk, 165 
sweetened condensed milk. 221 
fat, 626 
of the elements, 866-869 

Controller, 

^[ojoimier Culture, 531-534 



898 



IndKx of Subjects 



Mojonnier Evaporated Milk, 725, 

740-747 
Coolers, for sweetened condensed 

milk, 234-238 
Cream, acid test for, 601-603 
bacteria in, city regulations. 832 
city regulations on, 842-848 
definition of and standards for, 

812 
fat test for, 109 

flow sheet of manufacture, 853 
key to formulas for standardizing, 

151 
powder, score card for, 809 
problems in standardizing, 151- 

161 
sampling, 83 
sample of, composite, 85 
score card, 788, 789 
specific heat of, 652, 653, 656 
standardization of, 142-161 
standardization of, by Pearson's 

method, 144 
standardization of, by Cross's 

method, 146-149 
standardization of, by Erf's meth- 
od, 150 
standardizing for fat, in, 144, 147, 

148, 149 
state standards of bacteria in, 822 
sucrate of lime in, 636 
table giving composition of. 134- 

139 
test for remade, 609 
total solids test for, 126 

Cultures, 

amount of, to use in making but- 
termilk. 539, 543 

apparatus, for propagating pure, 
531 

effect of holding, at various tem- 
peratures, 529-530 

factors relating to growth of, 524 

jars, 536 

media for, 534 

pipettes, 538 

preparation of, 535-542 

quantity of, to add to media, 526- 
528 

relation of acid development and 
time of ripening of, 525 

score card for, 792 

use of, in making baker and pot 
cheese, 549 

use of, in making cottage cheese, 
548 

use of, in making cheddar cheese, 
549 



usi' of in making butter, 550 
use of, in making ice cream, 548 
Culture Controller, Mojonnier, 531- 

534 



Dairy farms, regulations relating to, 

840 
Dairy laboratory, 1-9 

equipment for, 4-7 

location of, 1 

plan of. 7-9 
Dairy products, 

analysis of, 554-683 

condensing, 705-718 

history of fat and total solids test 
on, 34-61 

laboratory for testing, 1-9 

microscopical examination of, 484. 
515-521 

miscellaneous information regard- 
ing. 849-864 

principals of fat and solids test 
for, 34-61 

sampling, 80-92 

score cards for, 772-809 

standards of, 810-848 

standardization of, 130-442 

testing, 93-141 
Definition of, 

buttermilk, 811 

cheese, 813-815 

condensed milk, 811 

condensed skim-milk, 811, 812 

cream, 812 

extracts, 818-822 

milk, 810 

sugars. 816-817 

sweetened condensed milk. 811 
Detection of, 

gums, 634-636 

preservatives, 609-613 

thickeners, 633-636 
Determination of, 

acidity of cheese, and milk, 601- 
604, 622 

adulteration of milk, 564-566 

albumin in milk, 575 

ash in milk, 576 

ash in cheese, 622 

casein in milk, 568-570 

citric acid in milk, 593-596 

fat in dairy products, 106-111 

of fat in cheese, 621 

of fatty acids in butter, 619 

foreign fat in milk fat, 626-632 

freezing point of milk, 656-660 



Indkx of Subjects 



899 



hydrogen ion concentration, 665- 

'682 
lecithin in milk, 592 
h'nie in dairy products, 576-578 
melting point of fat, 624-626 
milk fat in milk chocolate, 632 
moisture in butter, 614 
moisture in cheese, 621, 622-624 
nitrogen in milk, 570-572 
preservatives in milk, 609 
quality of casein. 573-575 
salt in butter, 615-619 
salt in cheese, 624 
sediment in milk, 605 
specific gravity of dairy products, 

554-564 
solids in dairj^ products, 120-129 
sugar in dairy products, 579-596 
viscosity of dairy products, 566 
Dextrose, sweetening power of, 286 

Directions, 

for making fat test on Mojonnier 
Tester, 93-119 

for making solids test on Mojon- 
nier Tester, 120-129 
Dishes, for Mojonnier test. 64, 65, 
n, 78, 79 

care of. 79 

weighing, 78 

influence of temperature on 
weight of, n 
Drip sample, 83 



Eggs, in ice cream mix, 286 
Elements, constants of the, 866-869 
Entrainment losses in the vacuum 

pan, 715 
Equipment, 

for making bacteriological counts, 

498 
for making culture buttermilk, 

532, 544-547 
laboratory, 5-7 

sweetened condensed milk, 233- 
238 
Ether, 7, 44-48 

function of, in Mojonnier test, 45, 

46 
purity of, 44 
Evaporated milk, 

action of, on tin and iron, 862 
adding sodium bicarbonate before 

sterilizing, 747, 740 
calculating Baume readings of, 
176-178 



calcium citrate as affecting quality 
of, 761-764 

changing temperature when mak- 
ing, 748 

coagulating point of, 725-737 

composite samples of, 164 

constants for, 165 

Controller, Mojonnier, 725, 740- 
747 

cooling, 179, 180 

definition of and standard for, 811 

effect of sterilizing temperatures 
on the nitrogeneous constitu- 
ents of: 754 

effect of acid content upon the 
coagulating point of, 726-728 

factors influencing color of, 764- 
769 

factors influencing failure of, to 
react to sodium bicarbonate, 
749, 750 

factors influencing heat coagula- 
tion of. 12S-lp 

factors influencing quality of, 761- 
764 

gases in, cans, 769, 770 

influence of concentration upon 
the coagulating point of, 734, 
735 

influence of freezing temperatures 
upon, 766 

influence of mineral constituents 
upon the coagulating point of, 
730-734 

influence products of bacterial 
growth the coagulating point of, 
735 

influence of method of forewarm- 
ing upon the coagulating point 
of, 736, 11>1 

laboratory report for, 169 

report blank for standardizing 
data, 169 

relation specific gravity, composi- 
tion and temperature in, 174- 
177 

sampling, 87 

score card for, 802-804 

spoilage of, 760, 761 

standardizing, 162-219 

standardizing before condensing. 
165-167, 192-210 

standardizing after condensing, 
211-219 

standardization tables, 180-190 

steam distribution when steriliz- 
ing, 738, 739 

sterilizing equipent for, 719-721 

sterilization of, 719-755, 758 



900 



Index of Subjects 



temperature to heat and hold, 

titratable acidity of, 765-766 
variations in the coagulating point 

of, 752-754 
viscosity of, 755-760, 767-769 
Evaporation, rate of, in the vacuum 

pan, 685, 686 
Extracts, definition of and stand- 
ards for, 812-822 
analysis of, 641-643 



Factors, of safetv, in standardizing, 

192, 249 
Farm inspection, score card for, 778 
Farm, regulations relating to scor- 
ing, 840 
Fat, (milk) 

acids in, 19 

color of, 17 

composition of, 19, 56 

detecting foreign in, 626-632 

defects in ice cream due to, 289 

estimation of, in milk chocolate, 
632 

function of, in ice cream, 281 

globules, 17, 18 

glycerine in, 19. 20 

homogenized, 18 

microscopical exammation of, 17, 
484 

melting point of, 19, 624 

specific heat of, 654, 655 

standards, 824-826. 830 

test for butter, 110 

test for cocoa, 110 

test for cheese, 110 

test for condensed milks, 107, 108 

test for cream, 109 

test for ice cream, 109 

test for malted milk and milk 
chocolate, 110 

test for milk powders, 111 

test for skim-milk, whey and but- 
termilk, 106 

test for whole milk, 106 
Fat constants, 626 
Federal standards, 810-822 
Flavors, in ice cream mixes, 286, 

288 
Flasks, Mojonnier, 64 

weighing, 96 

hanger for, 96 
Flow sheets of, 

butter, 850 



casein, 854 

cheddar cheese, 853 

condensed milk, 851 

cream, 850 

culture buttermilk, 854 

evaporated milk, 851 

general, of milk, 849 

ice cream, 852 

milk chocolate, 854 

milk powder, 853, 

milk sugar, 854 

sweetened condensed milk. 851 

whole milk, 850 

Formaldehyde, 84 

Formulas for standardizing cream 

and milk. 
Formula 1; Pounds of milk to 

separate, 153 
Formula 2; For lowering fat and 

solids. 154 
Formula 3; For raising fat. 157 
Formula 4; for fat, 159 
Formula 5; for solids. 160 

Formulas for standardizing evapo- 
rated milk. 
Formula 6; For lowering fat, 193 
Formula 7; For raising fat, 195 
Formula 8; For raising fat, 196 
Formula 9; For determining fat 

and solids in a mixed batch, 

202 
Formula 10; For lowering fat and 

solids, 205 
Formula 11; For lowering fat and 

solids. 205 
Formula 12; For lowering fat, 207 
Formula 13; For lowering solids 

not fat, 209 
Formula 14; For raising solids 

not fat. 212 
Formula 15; For using cream and 

condensed whole milk, 216 
Formulas for standardizing sweet- 
ened condensed milk. 
Formula 16; Using whole milk 

and skim-milk, 249 
Formula 17; Using cream. 252 
Formula 18; Using cream, 255 
Formula 19; Using cream, 257 
Formula 20; Using sweetened 

condensed skim-milk, 261 
Formula 21; Using unsweetened 

condensed skim-milk, 263 
Formula 22; Using unsweetened 

condensed whole milk, 266, 267 
Formula 23; Amount of sugar to 

use. 266, 267 



Index of Subjects 



901 



Formulas for standardizing ice 
cream mixes. 

Formula 24; For making a de- 
finite weight in the vacuum oan. 
316 

Formula 25; For making an in- 
definite weight in the vacuum 
pan, 319 

Formula 26; For low fat and high 
solids not fat, 321 

Formula 27; Both fat and solids 
not fat high but the fat in 
higher ratio, 324 

Formula 28; Both fat and solids 
not fat under standard, 328 

Formula 29; Both fat and solids 
not fat under standard, 332 
Freezer, ice cream, 

speed of, 458 

t3^pe of, 456 
Freezing point, 

of ice cream mixes, 275, 278 

of milk, 656-660 

of sugar on, 275 
Fruits, 

in ice cream mixes, 287, 288 
Fuchsin, 7 



Galalith, 12 
Galactose, 32 
Gas, 

relation of, consumption to steam 
production, 703, 704 
Gases, in evaporated milk, 769, 770 
Gauge, 

Green, 170, 171 

Gelatin, 

analysis of, 645-647 

condition of, 281 

defects in ice cream due to, 298 

function of, in ice cream mixes, 

281-284 
properties of a good gelatin, 

286 
relation of, to food value, 283 
relation of. to incorporation of 

air, 281, 282 
relation of, to overrun, 462' 
relation of, to smoothness in ice 

cream, 283, 284 
relation of, to viscosity. 282 
variation in qualit}^ of. 284 
viscosity of, water solutions of, 

282, 283 
Glass, heat transmission of. 863 



Globules, fat, 

homogenized. 18 

in ice cream, 18 

milk. 15. 17, 18 
Glycerin, 7 
Gums, 

detection of, 633-636 
Gum arabic, 

analysis, 647 
Gum tragacanth, 

analysis of, 648 

H 

Heat of combustion, 

in ice cream, 274, 275, 278 
Heat of Transmission, 

of metals, alloj^s and glass, 863 
Homogenization of, 

ice cream mix, 453-456 
Hood, for laboratory, 3 
Hot well, 

forewarming and heating in, 705- 
706 

heating milk in, 737, 738 

types of, 699 
Hydrochloric acid, 7 
Hydrogen ion concentration, 665- 

682 
Hydrometer, Baume, 

for evaporated milk, 179 



Ice cream, 

application of cultures in making, 

548 
available heat of combustion in, 

274. 278 
cause of sandiness in, 289-298 
defects due to composition, 289- 

300 
defects due to fat, 289 
defects due to gelatin, 298 
defects due to solids not fat, 289 
defects due to sugar, 298 
defects due to water, 299-300 
factors causing loss in overrun. 

460-462 
factors influencing overrun in. 

447-460 
fat globules in. 18 
fat globules in homogenized in, 

18^ 
fat test for, 109 
flow sheet of manufacture, 852 
freezing point of, 275. 278 



902 



Indkx of Subjects 



general facts reg'ardinp: overrun 

in, 443 
heat units required to melt. 276 
latent heat of, 276 
Alojonnier overrun tester for, 463- 

475 
normal heat of, 276 
nutritive ratios of, 276, 278 
overrun in, 443-475 
percentages of overrun, 274, 277, 

278 
phases in the freezing- of, 444-447 
plans for plant laboratory, 9 
prevention of sandiness in, 289-298 
]iroportion of water frozen in, 300 
sandiness, in, 289-298 
sampling, 87 
score card for, 798-801 
solids test for, 126 
specific heat of. 275, 278 
weight of, per gallon, 274, 277, 

278 

Ice cream mixes, 

acidity of, as affecting overrun, 
450-452 

aging of, as affecting overrun, 
450-452 

amount of, to draw into freezer, 
456 

available heat of combustion of, 
274, 278 

bacteria in, when prepared in the 
vacuum pan, 303 

causes of variation of composi- 
tion of, 272 

composition of, as affecting over- 
run, 447-450 

composition of products used in 
making, 313 

compositon ratios of, 273 

composition and standardization 
of, 272-432 

eggs as filler in, 286 

freezer, type of, 456 

freezing point of, 275, 278 

function of fat in, 281 

function of gelatin, in, 281-284 

function of solids not fat in, 281 

function of sugar in, 281 

importance of pasteurization in 
making, 292 

improvers in, 286 

influence of age on viscositv of 
273 

inlluence of gelatin on viscositv 
of, 273 

influence of solids not fat on vis- 
cosity of, 273 



influence of temperature on vis- 
cosity of, 273 

homogenization of, 453-456 

keeping qualities of, when pre- 
pared in the vacuum pan, 3Q3 

methods for compounding, 302- 
305, 312-316 

Mojonnier vacuum pan method, 
for preparing, 302-304 

nutritive ratios of, 276, 278 

raw materials in, 272 

specific gravity of, 274, 304 

specific heat of, 275, 278 

starch, as filler in, 286 

steps involved in standardizing, 
301 

temperature to hold. 855 

thirteen compositions of. 273 

titratable aciditv of, 274 

viscosity of. 273. 277. 452 

vitamincs in, 281 

weight per U. S. Gallon of, 274 
Incubation, 

period of, when making bacteria, 
count, 507 

temperature of, when making 
bacteria count, 514 

of culture, 540 
Inspection of milk, 

score cards for. 772>-779 
Invert sugar, 

sweetening power of, 285 

percentage composition of, 285, 
286 

K 

Keys to formula, 

for cream, 151-152 

for evaporated milk, 191-192 

ice cream mix, 311, 312 

sweetened condensed milk, 248 

whole milk, 151, 152 
Laboratory, 1-9 

apparatus and chemicals for, 4, 7 

general plans for, 7-9 

lighting for. 3 

tables and desks for, 2 

ventilation and temperature of, 2 
Lactic acid, 21, 22, 26, 27, 32 
Lactometer, 

Board of Health, 558, 560 

determining specific gravity by 
means of, 557-564 

Quevenne, 57, 558, 560 
Lactose, sec milk sugar 
Lecithin, 15, 30 

(ktermination of. in milk, 592 



IndKX of SUBIKCTS 



903 



Levulose, sweetened power of, 286 
Lime in dairy products. 576-378 

M 

Macroscopical colony count, 500-515 
Malted milk, 

composition of, 441 

condensing, in the vacuum pan, 
718 

fat tests for, 110 

sampling, 91 

solids tests for, 127 
Maltose, sweetening power of, 286 
Mammals, composition of milk from 

ditterentv 888 
Measures, tables for conversion of, 

876-882 
Melting point, of milk fat, 624 
Metals, 

action of milk on, 856-863 

solubility of, in milk, 858 

transmission of heat of, 863 
Metallic lactates, 

amount required to impart taste 
to water, 857 

amount actually dissolved, 861 

Micfrcscope, 

bacteria count bv means of, 515- 

520 
directions for use of, 476-483 
examination of milk fat bv means 

of. 484 
examination of milk sugar b^' 

means of, 484 
names of various parts of, 477 
standardization of, 517 
use of. in the dairy industrv. 476. 

483 
Milk, 

analysis of. 568-572. 575-609 

albumin, in, 29 

ash. in, 29 

bacteriological counts on. 500-521 

certilicd, score card for. 784-786 

citv regulations relating to. 842- 

848 
critric acid in, 32 
color test for, 609 
composite sample of, 83 
composition of, from different 

mammals, 888 
composition, variations, in, 12, 13 
condensing, in the vacuum pan, 

705-715 
constituents of. 10-33 



constituents, preparation of pure, 
660-665 

detection of specific pathogens in, 
522 

distribution of constituents of, 
14-15 

drip sample of, 83 

fat in, 11, 12, 17 

fat globules in, 18 

fat tests for, 11-20 

11 ow sheet of, 849-850 

freezing point of, 656-660 

gases in, 14 

heated tests for, 609 

inspection, 77?>-777 

key to formulas for standardiz- 
ing, 151 

metallic taste in, 861 

mineral constituents of, 29 

physical properties of, 10 

regulations relating to, 831-834 

sampling, 80-87 

sediment test for, 605 

solubilty of metals in, 858 

specific heat of, 652-656 

standardization of, 142-159 

state standards of, 822 

testing for adulteration, 564 

testing for acidity in, 601-603 

test for solids in, 124 

types of bacteria found in. 485-498 

unsalable, 834 

vitamines in, 31 

Milk chocolate, 

composition of, 440 
estimation of milk fat in. 632 
fat test for, 110 
riow sheet of, 854 
sampling, 91 
solids test for, 127 

Milk, evaporated, see evaporated 
milk 

Milkers, regulations relating to, 833 
Milk foods, composition of, 441 
Milk house, regulations relating to. 

837 
Milk plants, regulations relating to, 

839 
Milk powder, 

fat test for. 111 

fiow sheet of, 853 

sampling, 91 

score card for, 808 

solids test for, 128 

standardization of, 435-438 

temperature to heat and hold, 856 



904 



Index of Subjects 



Milk sugar, 

available heat of combustion of, 

275 
crystalline condition of, 25, 26, 27 
crystallization of, in sweetened 

cond. milk, 236 
decomposition of, 226 
determination of, 579-591 
form of crystallization of, 289 
flow sheet of, manfacture, 854 
factors influencing solubility of, 

290-298 
photomicrographs of, crystals. 236 
preparation of pure, 664 
microscopical examination of, 484 
relation of sandiness in ice cream 

to, 289-298 
solubility of, 23-25, 296 
sweetening power of, 286 
uses of, 27-28 

Milk tester, Mojonnier 
description of, 64-68 
directions for making fat test, 

using, 93-119 
directions for making solids test. 

using, 120-129 
illustrations of, 62-64, 68, 69 
operation of, 72-79 
wiring for, 72 

Milk utensils, regulations relating 
to, 838 

Mineral constituents in milk, 29 

Mixers, ice cream batch, 308-310 

Mojonnier, 

fat tests, 43-56 

Culture Controller, 531-534 

Evaporated Milk Controller, 725, 

740-747 
Ice Cream Packaging Machine. 

286 
Ice Cream Overrun Tester, 463- 

475 
solids test, 56-61 
sweetened cond. milk equipment, 

235 
Tester, 4, 35, 43-61, 62-69. 164 
Vacuum Pan, 687 
Vacuum Pan, method for making 

ice cream mixes, 302-304 
Viscosimeter, 273 

Mojonnier fat test, 

adding reagents in. 97-98 

causes of high and low results 

when making, 115 
directions for, 93-119 
for buttermilk, skim-milk, and 

whey. 106 



for cheese, cocoa, butter, malted 
milk, milk chocolate, 110 

for condensed milk, 108 

for evaporated milk, 93-106 

for ice cream, and cream. 109 

for milk, 93 

for milk powder, HI 

for unsweetened cond. milk, 107 

precautions in making, 112 
Mojonnier Milk Tester, 

description of parts, 64-68 

dimensions of, 68-69 

directions for making fat tests on, 
93-119 

directions for making solids tests 
on. 120-129 

illustrations of. 62-69 

operation of, 72-79 

power unit of, 70 

N 

Nitrogen, determination of, in milk. 
570-572 

Nutritive ratios, of ice cream. 276- 
278 



Oil, relation of. consumption to 

steam production, 703-704 
Olein, 15, 19 
Operation of, 

microscope, 481-483 

Mojonnier Culture Controller, 

532-543 
Mojonnier Evap. Milk Controller. 

725. 740-747 
Mojonnier Milk Tester, 62-69, 70- 

79 
Moionnier Overrun Tester, 463- 

475 
sterilizers. 719-724 
vacuum pan. 705-718 
Overrun, in ice cream, 280, 443-475 
facts regarding, 443 
factors influencing proper, 447-460 
how to retain, 460 
loss in, 460-462 
phases in the freezing of ice 

cream and obtaining, 444-446 
proper, 447 
standardizing the, 473 
'iV\stcr. .Mojonnier. 463-475 



Palmatin, 15, 19 
Pan, Vacuum, see Vacuum Pan 
Pasteurization, state standards for, 
823 



IXDKX OF vSuBjECTS 



905 



of ice cream mixes, 292 
Pepsin, in ice cream mix, 286 
Petroleum ether, 44, 48 
Physical constants of the elements, 

866-869 
Physical properties, of ice cream 
mixes, 272-300 
of milk, 10, 11 

Pipettes, 

directions for weighing, 95 
Piping, for vacuum pan, 692-693 
Plans, for dairy laboratories, 7-9 
Plate (Petri) method, for making 

bacteriological counts, 500-515 
Powders, milk, 

fat test for. 111 

sampling, 91 

solids test for, 128 

standardizing of, 435-438 
Power unit, for Mojonnier Milk 
Tester, 6, 64, 66 

Proper,ties, 

chemical, of milk, 12-33 
chemical, of ice cream mixes, 272- 
300 

physical, of milk, 10, 11 
physical, ice cream mixes, 272-300 
Proteins, available heat of combus- 
tion of, 275 

R 

Reagents, for ]\lojonnier Test, 6, 7, 

44-48, 98. 99, 106 
Regulations, see standards 
Rennet, in ice cream mix, 286 
Rheostats, for Mojonnier Tester, 66 
Report blanks, 

cost, of ice cream mix, 307 
laboratory, 105, 168, 169, 225 
Rose Gottlieb, fat tests, 35, 39, 41, 43 



Salt, analysis of, 638-641 

test for butter, 615-618 
Samplers, 81 
Samples, composite, see composite 

samples 
Sampling, 

accessories, for, 80, 81 

butter, 88 

Ijuttermilk, 89 

cheese, 89 

cocoa, 92 



cream, 83 

evaporated milk, 87 

ice cream mix, 87 

milk, 82-86 

milk powder, malted milk and 

milk chocolate, 91 
sweetened condensed milk, 87 
whey, 90 
Sandiness, in ice cream, 

causes and prevention of, 289-298 
influence of size of milk sugar 

crystals on, 290-293 
influence of amount of overrun 

on, 293 
influence of composition of milk 

on, 293 
influence of miscellaneous factors, 

on, 293 
influence solubilitv of milk sugar 

on, 294-298 
relation of milk sugar to, 289-298 
summary of conclusions on causes 

of, 296-297 
Score cards, 

development of, 772 

for butter. 790-792 

for cheese, 794-795, 796, 798 

for cream, 788 

for culture, 792 

for evaporated milk, 802-804 

for milk, m-m, 787 

for milk powder, 808-809 

for stores, handling milk. 783 

for sweetened condensed milk. 

804-808 
for veterinarian, 780 
value of, 772 
Sediment test for milk and cream, 

605 
Shakers, for evaporated milk, 757- 

758 
Sherbet, for use, with Mojonnier 

Packaging Machine, 287 
Skim-milk, 

fat test for, 11, 16 
sampling, 86 
score card for, 787 
solids test for. 124 
specific heat of. 652-653-656 
Sodium bicarbonate, use of, in 

evaporated milk. 740, 747-751. 

714 
Solids, in dairy products, 120-129 
defects in ice cream due to, 289 
function of, in ice cream mixes. 

281 
standards for. 824-826, 829 



906 



Indkx of Subji:cts 



variations in, 13, 15 
Solids, not fat, 

defects in ice cream due to, 289 
composition ratios of, for ice 

cream mixes, 273 
in milk, 11 

specific gravity of, 16 
standards for, 824-826, 830 
variations in, 13, IS 

Solubility, of milk sugar, 23, 25, 

294, 296 
Solutions, standard, preparation of. 

596-600 
Specific gravity, 

calculation, in evaporated milk. 

176-178 
conversion to Twaddell, 865 
conversion to Baume, 870-874 
determination of. in dairy prod- 
ucts, 649-652 
determinations, 554-560 
instruments for determining, 179. 

554-564 
of alcohol, 44, 884, 886 
of ammonia, 44 
of butter, 654-656 
of butter fat, 654-655 
of evaporated milk, 172-181 
of ice cream, 275 and 278, 304 
of milk, 59, 652, 656 
of sweetened condensed milk. 

22S-235 
of unsweetened condensed milk, 

434-437 
of whey, 654 

solids in milk by formula, 58 
standards relating to, 833 
Spoilage, detection of, in (.vapor- 

ated milk, 760-761 
Standards, 810-848 
citv, 828-848 
state, 822-828 
state, on bacteria content, of milk. 

822 
state, on pasteurization. 823 
U. S. Department of Agriculture. 

810-822 
Standardization, 
definition of, 130 
obtaining weights for, 132 
order of operations in, 140, 141 
use of tables for, 132 
successive steps in, 131 
Standardization, of milk and cream, 

142-161 
by Pearson's method, 143-145 
by Cross's method, 146-149 



by Erf's method, 150, 151 
problems, 151-161 

Standardization of evaporated milk, 

order of operations, 166-169 
problems for, 192-219 
tables, 180-190 

Standardization of ice cream mix, 

301-432 
definition of, 301 
methods of compounding, 302-305 
problems, 310-432 
steps involved in, 301 

Standardization of sweetened con- 
densed milk, 220-271 
principles underlying, 162, 220 
problems in, 249-271 
steps in, 221-222 

Standardization problems, 

problems 1-6, for cream and 

whole milk, 143-161 
problems 7-17, for evaporated 

milk, 192-219 
problems 18-24, for sweetened 

condensed milk, 249-270 
])roblems 26-36, for ice cream 

mixes, 316-350 
problems 2>7, example 39, proof 

of accuracy of standardizing 

tables, 366 
problem i7. example 40, proof, 

of accuracy of standardizing 

tables, 366 " 

Starch, in ice cream mix. 286 

State Standards, 822-828 

Steam, available heat units in, va- 
rious pressures, 708 

condensed into whole milk, in the 
hot wells, 700 

distribution in sterilizer, 738-739 

relation of. to fuel production, 
703-704 

reciuired to condense milk in the 
vacuum pan, 698-705 

re(|uired to forewarm and con- 
dense, 701-702 

saturated, properties of, 874-875 
Sterilization, of evaporated milk. 

719-755, 758 
Sterilizers, 

for use with Mojonnier Culture 
Controller, 534 

for sterilization of evaporated 
milk, 720-721 

steam distribution in evaporated 
milk. 7,^^8-739 



IXDF.X OF SUBM'XTS 



90/ 



Store, score card for, handling 
milk, 783 

Striking the batch, of evaporated 
milk, 171-181 
of s\\eetcncd condensed milk, 
225-233 

Sucrate of lime, in milk and cream. 
636 

Sucrose, (cane sugar), (beet sugar) 
available heat of combustion, of. 

275 
crystals, 226 

defects in ice cream due to, 298 
determination of. 583-591 
function of, in ice cream mix. 285 
sweetening power of, 285, 286 

Sugars, definition of, and standard 

for, 816-818 
Sugar, cane, see sucrose 

Superheating milk, in the vacuum 
pan, 710-712 

Sweetened condensed milk, 

capacity and size of standard 

equipment for manufacture of, 

234 
composition of. 239 
composite samples of. 222 
condensing, in the vacuum pan, 

716 
constants for, 221 
definition of, 811 
factor of safety in standardizing. 

249 
Federal standard for, 811 
kev to formulas for standardiz- 

i'ng. 248 
methods of testing. 222 
ot)taining weights of. 225 
operation of vacuum pan when 

making. 716 
order of operations when stand- 
ardizing, 223 
pycnometer cup for, 233 
problems in standardizing. 249- 

271 
relations of specific gravitv in, 

226-232 
sampling, 87 
score card for, 804-808 
standardization of, 220-271 
solids test for, 125 
test for fat in, 108 
temperature to heat and hold. 856 
types of coolers for. 235-238 



Tanks, 

capacity of cylindrical, 887 
evaporated milk holding, 179-180 
ice cream holding, 308-310 
ice cream batch mixing, 308-310 

Temperature, 

for holding manufacturing and 
storing dairy products, 855 

freezing, 832 

inlluence of, on the solubilitj^ of 
metals in milk, 858 

of brine, for freezing ice cream, 
457. 458 

of mix. 459 

of ice cream. 459 

of hardening room, 460 

of incubation, 514, 524 

of sterilization. 721, 722-724, 742 

table for conversion from Centi- 
grade to Fahrenheit and visa 
versa, 883 

Test, 

acid, for milk and cream. 601 
alcohol for milk. 606 
bacteriological, 498-521 
color. 609 

fat, 35-41. 43-61. 93-119 
heated milk, 609 
microscopical, 515-521 
salt, for butter, 615-618 
sediment for milk, 605 

Tester, 

Mojonnier Milk, 4. 35, 43-61, 62- 

72, 93-129, 169 
Mojonnier Overrun Tester, 463- 

475 
sediment, 605 

Thermometers, 6, 65 
Reckman, 275 

Thickeners, detection of, 633-636 

Total solids, 

by formula. 59 

cause of low and high results 

when making, 128-129 
composition ratios of, 273 
for butter milk, 124 
for evaporated milk, 124 
for ice cream, cream, cheese and 

butter, 126-128 
for milk chocolate, malted milk 

and cocoa, 127 
for sweetened condensed milk. 

125 



908 



Index of Subjects 



for whole milk powder, skim-niilk 
powder, and buttermilk powder, 

128 
tests. 56-58 

Trier, butter and cheese, 81 

U 

Unsweetened condensed milk, 

action of, on tin and iron, 862 
definition of, 811 
fat test for, 108 
flow sheet of, manufacture, 851 
processing score card for, 801 
solids test for, 124 
specific gravity of. 434, 436. 437 
standardization of. 433-444 
temperatures to heat and hold. 
856 

V 

Vacuum pan, air leaks in, 713 

cleaning, 713, 714 

condensing buttermilk in, 718 

condensing ice cream mix in. 302, 
303, 717. 718 

condensing malted milk in, 718 

condensing whey in. 718 

condensing whole and skim-milk 
in, 716-717 

condition of heating surfaces, 712 

description of, 686-689 

economic advantage of, 684, 686 

entrainment losses in, 715 

history of, 684 

how to strike the liatch in, 710 

how to superheat the batch in, 
710, 711, 712 

increase of water required due to 
the decrease in the temperature 
of the w^ater vapors, 697, 698 

location of control devices on, 
693, 694 

method, Mojonnier, for making 
ice cream mixes, 302-304 

operation of, 705-718 

precautions in operation of, 712- 
715 

purpose and use of, 684-718 

rate of evaporation in, 687, 688 

relation of the water required in 
the condenser to the water re- 
moved from the milk in, 694, 
695, 696 

sizes and capacities of, 689, 690 

sizes of piping for, 692-694 

sizes of vacuum pumps for, 692 



steam required to condense milk 

in, 702 
striking devices for, 178 
striking the evaporated milk 

batch in, 171-181 
striking the sweetened condensed 
milk batch in. 225-233 
water, steam and fuel required to 

operate, 703, 704 

Vacuum oven, 

vacuum in, for solids test, 122, 

123 
valves controlling, 103 
temperature for solids, 122 

Vacuum pump, care of, 70 

filling with oil, 104 

for jMojonnier Tester, 70 
Vacuum pump, wet. 691-692 

sizes of. 692 
Vanilla extracts, 

analysis of, 641-645 
Ventillation, for laboratory. 2 
Veterinarian score card, 780 
Viscogen, see sucrate of lime 
Viscosimeter, 

Mojonnier-Doolittle, 273, 566-568 
Viscosity, 

determination of, in dairv prod- 
ucts, 566-568 

of evaporated milk. 743-751, Kil- 
led 

of ice cream mixes. 273. 277 

relation of gelatin to. in ice cream 
mixes. 282 
Vitamines, 

in milk, 30 

in ice cream mix, 281 

W 
Wagons, regulations relating to de- 
livery, 839 
Water, amount of metal required to 
impart taste to, 857 
circulating unit, 70 
defects in ice cream due to, 289- 

300 
filling tank with, 104 
in milk, 11. 12. 16 
in Mojonnier test. 44. 45 
puritA' of. 45 
required in the vacuum i)an. 694- 

698 
supplv. regulations relating to, 
833 
Water circulating unit, 
for iNIojonnier Tester, 70 



Index of Subjects 



909 



Weighing, 

cross, 94 

directions for, 73-78. 94-97 

evaporated milk, 170 

extraction flask, 96 

fat dishes. 102 

influence of temperature in, 73, 77 

pipettes, 94, 95 

samples for solids test, 120, 121 

Weights, tables for conversion of. 
876-882 

Weights, 

care of. 74 

directions for recording. 76 

for chemical balance. 74. 75 

metric, 76 

of evaporated milk, methods for 

obtaining. 170 
of ice cream mixes, 274, 277 



of various dairy products used in 
standardizing ice cream mixes, 
306 

Whey, 

condensing, in the vacuum pan, 

718 
fat test for. 106 
sampling, 90 
specific heat of, 654 
temperature to hold, 855 
total solids test for. 124 



X 



Xylol, 7 
Yogurt, 27 
Zinc dust, 7 



